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Journal articles on the topic 'Larval stages'

Author: Grafiati
Published: 4 June 2021
Last updated: 11 February 2022

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1

CURIEL, JOSEFINA, and JUAN J. MORRONE. "Association of larvae and adults of Mexican species of Macrelmis (Coleoptera: Elmidae): a preliminary analysis using DNA sequences." Zootaxa 3361, no. 1 (June 29, 2012): 56–62. http://dx.doi.org/10.11646/zootaxa.3361.1.5.

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Insect life stages are known imperfectly in many cases, and classifications are usually based on adult morphology. This isunfortunate as information on other life stages may be useful for biomonitoring. The major impediment to using elmid(Coleoptera) larvae for freshwater biomonitoring is the lack of larval descriptions and illustrations. Reliable molecular proto-cols may be used to associate larvae and adults. After adults of seven species of Mexican Macrelmis were identified morpho-logically, seven larval specimens were associated to them based on two gene fragments: Cox1 and Cob. The phylogeneticanalysis allowed identifying the larval specimens as Macrelmis leonilae, M. scutellaris, M. species 7, M. species 10, and M.species 11. Two species based on adults associated uncertainly with one larva, and one larva did not match with any adult. Adult/larval association in elmids using DNA sequence data seems to be promising in terms of speed and reliability.
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2

Gosik, Rafał, Peter Sprick, and Michael G. Morris. "Descriptions of immature stages of four species of the genera Graptus, Peritelus, Philopedon, and Tanymecus and larval instar determination in Tanymecus (Coleoptera, Curculionidae, Entiminae)." ZooKeys 813 (January 7, 2019): 111–50. http://dx.doi.org/10.3897/zookeys.813.30336.

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The mature larva and pupa of Graptustriguttatustriguttatus and the mature larva of Peritelussphaeroides are described for the first time. The larvae of Philopedonplagiatum and Tanymecuspalliatus are re-described. Five larval instars were determined in Tanymecus, thereby correcting doubtful data in the literature. The relationship between larval growth, number of larval instars, head width of the mature larva, and the adult weevil is explained using the example of Tanymecus. The nearly constant ratio of subsequent larval instars in head width ratio, termed “growth factor” and derived from Dyar’s ratio, is used for the determination of larval instars. Larval collecting and breeding data are discussed in relation to their significance for the clarification of life-cycles.
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3

Zavala-Leal, I., S. Dumas-Lapage, and R. Peña-Martinez. "ORGANOGÉNESIS DURANTE EL PERIODO LARVAL EN PECES." CICIMAR Oceánides 26, no. 2 (December 4, 2011): 19. http://dx.doi.org/10.37543/oceanides.v26i2.100.

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La presencia de un periodo larval caracteriza a los peces con ontogenia indirecta. Este periodo de desarrollo implica una serie de transformaciones encaminadas a la adquisición de las características biológicas y ecológicas propias de la especie; y en muchos casos culmina con cambios de distribución y hábitos alimenticios. El periodo larval incluye cuatro estadios de desarrollo: larva vitelina, larva pre-flexión, larva flexión y larva post-flexión. Cada estadio de desarrollo presenta características asociados a cambios en las diferentes prioridades durante el crecimiento. De esta forma, durante los estadios de larva vitelina y larva pre-flexión, la prioridad es incrementar las posibilidades de supervivencia a través de enfatizar la capacidad alimenticia y de evasión de depredadores, lo cual se ve reflejado en una mayor diferenciación de estructuras asociadas a estas funciones. La larva flexión se caracteriza por presentar un mayor grado de funcionalidad de los órganos y estructuras desarrolladas anteriormente. Finalmente, durante el estadio de larva post-flexión se presentan los cambios más agudos con respecto a la funcionalidad de los órganos ya desarrollados. En el presente trabajo se realiza la descripción del desarrollo de estos órganos para cada uno de los estadios de desarrollo larval, haciendo referencia en las diferencias y semejanzas entre distintas especies de importancia comercial. Organogenesis during the larval period in fishes The presence of a larval period is characteristic of fishes with an indirect ontogeny. Many transformations involved in this period lead to the acquisition of biological and ecological characteristics of each species, that culminate in changes in distribution and feeding habits. Larval period includes four developmental stages: viteline larvae, pre-flexion larvae, flexion larvae and post-flexion larvae. Each developmental stage showed inherent characteristics associated with changes in priorities during growth. During the viteline larvae and pre-flexion larval stages, priority is about increasing the survival possibility through an increase in the capacity of feeding and escaping predators which is reflected in the development of structures involved in these activities. The flexion larva is characterized by a greater degree of functionality of organs and structures previously developed. Finally, the post-flexion larvae show the most drastical changes in the functionality of developed organs. In this work, we present a description of the development of these organs, taking into account differences and similarities between species.
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4

TORII, TAKAAKI, and MASATOSHI NAKAMURA. "DNA identification and morphological description of the larva of Eoneureclipsis montanus (Trichoptera, Psychomyiidae)." Zoosymposia 10, no. 1 (August 9, 2016): 424–31. http://dx.doi.org/10.11646/zoosymposia.10.1.39.

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Six genera of Psychomyiidae (Trichoptera) are known from Japan: Psychomyia, Tinodes, Lype, Metalype, Eoneureclipsis and Paduniella. A psychomyiid larva presumed to be Eoneureclipsis montanus was collected in Japan. We compared the COI sequence data of this putative E. montanus larva with those of identified adults to associate adult and larval life stages. Molecular evidence is presented to support the relationship between adults and larvae of E. montanus in Japan. Illustrations of E. montanus larval characters and a key and character matrix to genera of mature larvae of Japanese psychomyiids are provided.
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5

ARCHANGELSKY, MIGUEL, and MARIANO C. MICHAT. "Morphology and chaetotaxy of the larval stages of Andogyrus seriatopunctatus Régimbart (Coleoptera: Adephaga: Gyrinidae)." Zootaxa 1645, no. 1 (November 23, 2007): 19–33. http://dx.doi.org/10.11646/zootaxa.1645.1.2.

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The larval stages of Andogyrus seriatopunctatus Régimbart are described and illustrated, including morphometric and chaetotaxic characters. A larval ground pattern for the chaetotaxic characters is presented; it is based on first instar larvae of A. seriatopunctatus. Unidentified larvae of Dineutus MacLeay and a third instar larva of Gyrinus argentinus Steinheil were also inspected. For chaetotaxic homologization comparisons with other adephagan families were performed, mainly with Carabidae and Dytiscidae. The ground pattern is considered provisional due to the lack of previous studies in this family. Larvae of A. seriatopunctatus are briefly compared to those of A. buqueti (Aubé). Notes on the biology of A. seriatopunctatus are also included.
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6

MAGALHÃES, Célio, and Nelma MEDEIROS. "The Larval Development of Palaemonid Shrimps from the Amazon region reared In the laboratory. VII. Abbreviated development of Pseudopalaemon amazonensis Ramos-Porto, 1979 (Crustacea: Decapoda: Caridea)." Acta Amazonica 28, no. 4 (December 1998): 433. http://dx.doi.org/10.1590/1809-43921998284448.

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Larval development of the freshwater shrimp Pseudopalaemon amazonensis Ramos-Porto was studied in the laboratory based on the offspring of ovigerous females collected in a small “terra-firme” forest stream near Manaus, Brazil. Ovigerous females with a mean total length of 36.5 ± 1.9 mm carried 13-19 eliptical, yolk-rich eggs measuring 2.55 ± 0.16 x 1.64 ± 0.11 mm. The larval period consisted of 3 benthie stages and the larvae accomplished metamorphosis after 7-8 days without feeding. The newly-hatched larva had sessile eyes and all appendages, except for the uropods; chelipeds were present as uniramous buds, but walking legs were fully developed and functional. Descriptions and illustrations of the 3 larval and first juvenile stages are presented.
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7

M, Madhavi, Babu Rao G, and Srinivas V. "Morphological Abnormalities of Betulinic Acid from Ziziphus Jujuba Against the Callasobruchus Chinensis (Coleoptera: Bruchidae)." Biosciences, Biotechnology Research Asia 16, no. 2 (June 28, 2019): 411–16. http://dx.doi.org/10.13005/bbra/2756.

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Betulinic acid is a compound isolated from bark of Ziziphus jujuba. Betulinic acid,a triterpenoid. Betulinic acid exhibits a broad range of biological activities. It is an insect growth regulator, we observed the effect of different concentrations (10, 8, 6, 4and 2 μg / μl doses) Betulinic acid on Callosobruchus chinensis growth and development, in our observations we observed various morphological abnormalities like degeneration, deformation in larval, pupal stages. Untreated Callosobruchus chinensis showed normal in the developmental stages with the larval instar stages and henceforth developimg into pupa without any deformities. However Betulinic acid affected larval instars showed disrupted structures of the cuticle like tanning of cuticle and abnormal larvae over-aged larva with either complete or partial damage of pupa. The results demonstrated that Betulinic acid causes rapid cessation of growth due to disruption of larval structure and inhibition of growth following topical treatment on 4th 5th instar and pupae of Callosobruchus chinensis.
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8

XU, TIAN, CHAOSHU ZENG, and KATE S. HUTSON. "Morphological descriptions of the larval and first juvenile stages of the decorator crab Camposcia retusa (Latreille, 1829) from laboratory-reared material." Zootaxa 4577, no. 2 (April 5, 2019): 295. http://dx.doi.org/10.11646/zootaxa.4577.2.4.

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The complete larval and first crab stages of the decorator crab Camposcia retusa (Latreille, 1829) are described and illustrated based on laboratory-reared material for the first time. Specimens were obtained from larvae hatched from adult crabs collected from coral reefs of Queensland, Australia. Newly hatched larvae were successfully reared to settlement as the first-stage crabs. Larval development consisted of two zoeal stages and one megalopal stage. The morphology of each larval stage was compared with those available from a previous study using material from the Red Sea. Due to substantial differences in morphology of the second zoeal and megalopal stages between the two studies, we argue that these larval stages described by the earlier report may not be that of C. retusa. Finally, the morphological characters of both larval and first crab stages of C. retusa are also compared with the corresponding stages of previously reported Inachidae.
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9

Einer, H., and E. Ellegård. "Nasal myiasis by Oestrus ovis second stage larva in an immunocompetent man: case report and literature review." Journal of Laryngology & Otology 125, no. 7 (May 24, 2011): 745–46. http://dx.doi.org/10.1017/s002221511100096x.

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AbstractObjective:We report a case of an Oestrus ovis larva which developed into the second larval stage within a healthy, immunocompetent human, and we review the relevant literature.Methods:Clinical case report and Pubmed search of reports of human nasal myiasis due to Oestrus ovis, especially those describing the larval stage.Results:Humans are not normally hosts of the sheep nasal bot fly, but infestations by its larvae have been described. The eye is the most common site, but larvae have occasionally been found in the human nose. Transformation of larvae into the second and third stages, within the human nose, is even more uncommon.Conclusion:To the best of our knowledge, we report the first Swedish case, and the third case world-wide, of Oestrus ovis larval development beyond the first larval stage, within an immunocompetent, healthy human.
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10

Wehrtmann, Ingo S., and Luis Albornoz. "Larvae of Nauticaris magellanica (Decapoda: Caridea: Hippolytidae) reared in the laboratory differ morphologically from those in nature." Journal of the Marine Biological Association of the United Kingdom 83, no. 5 (September 19, 2003): 949–57. http://dx.doi.org/10.1017/s0025315403008130h.

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The variability of larval morphology in the caridean shrimp Nauticaris magellanica cultivated in the laboratory was analysed, and its applicability for the identification of larval stages collected from the plankton evaluated. Both morphometric and meristic variability of selected appendages was analysed comparing larvae from the rearing experiment with those obtained from the plankton. Larval development in the laboratory consisted of at least nine zoeal and five decapodid stages, followed by the first juvenile stage. Larvae collected from the plankton, comprising individuals from zoea II to, presumably, zoea VIII, were generally more developed and had a larger size than the corresponding stages reared in the laboratory. Cultured larvae showed a high exophenotypical variability starting with zoea IV, which impeded an immediate determination of larval stages obtained from the plankton.
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11

RONDEROS, MARÍA M., CARLA G. CAZORLA, and GUSTAVO R. SPINELLI. "The immature stages of the biting midge Culicoides debilipalpis Lutz (Diptera: Ceratopogonidae)." Zootaxa 2716, no. 1 (January 22, 2019): 42. http://dx.doi.org/10.11646/zootaxa.2716.1.3.

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The fourth instar larva and pupa of Culicoides debilipalpis Lutz, 1913 are described, illustrated, and photomicrographed from material collected in tree-holes of Salix sp. in Entre Rios Province, Argentina by using binocular, phase-contrast, and scanning electron microscopy. Measurements of instars I–IV are also presented. The larva shows features typical to carnivorous-predatory larvae, as well as characters typical of larvae occurring in tree holes and clean water. Details on larval biology, habitat, and feeding behavior are given.
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12

STUR, ELISABETH, and TORBJØRN EKREM. "Exploring unknown life stages of Arctic Tanytarsini (Diptera: Chironomidae) with DNA barcoding." Zootaxa 2743, no. 1 (January 18, 2011): 27. http://dx.doi.org/10.11646/zootaxa.2743.1.2.

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We present the first results from a project on Spitsbergen and Bear Island where the ultimate goal is to provide genetic and morphological identification keys to all species. Five Tanytarsini species have been recorded from Svalbard. By sequencing partial COI gene sequences, we have associated larvae of all of these, and describe the hitherto undescribed larval stages of Microspectra insignilobus Kieffer, M. radialis Goetghebuer and Tanytarsus heliomesonyctios Langton. We also present keys to larva, pupa and imagines of all Tanytarsini species found on Svalbard and discuss larval morphology in relationship to characters preserved in subfossil material. Of particular interest is the mandible and mentum of T. heliomsonyctios which show close resemblance to the tentatively associated larvae of Corynocera oliveri Lindeberg. An overview over Tanytarsus species with “lugens-type” larvae is given and the phylogenetic value of mandibular accessory teeth is briefly discussed.
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13

Rötzer, Marie A. I. N., and Joachim T. Haug. "Larval Development of the European Lobster and How Small Heterochronic Shifts Lead to a More Pronounced Metamorphosis." International Journal of Zoology 2015 (2015): 1–17. http://dx.doi.org/10.1155/2015/345172.

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We redescribe the larval stages of the European lobster,Homarus gammarus, based on autofluorescence composite imaging. We focus on larval stages (II) to (IV). Compared to the American lobster,Homarus americanus, differences are most apparent in stage (III). This stage appears more mature inH. gammarus; for example, the rostrum is already curved and bears spines, and the appendages are better developed and longer and more differentiated. InH. americanusstage (III) shows a stronger resemblance to stage (II). As a result of the morphology of stage (III), the “metamorphic” moult between stage (III) and stage (IV) inH. gammarusis less drastic than inH. americanus. Metamorphosis is characterised by two criteria. It involves (1) a drastic change in morphology in (2) a short amount of time. It has hence been suggested that a more pronounced metamorphosis evolves by two factors affecting these criteria, namely, (1) the evolution of specialised larval features, which increase the morphological disparity between larva and adult that makes the change of morphology more drastic, and (2) the skipping of entire stages. This means larval forms ancestrally moult over several intermediate forms into the definite adult morphology. Yet, in more derived forms the stages with intermediate morphologies are no longer expressed; highly specialized larvae moult into the adult within a single moult (in the most extreme case) hence bridging the morphologies of larvae and adult in a shorter amount of time. The example of the twoHomarusspecies demonstrates that this explanation is not the only possible one. Additionally, differences of a single larval stage (in this case larval stage (III)) can lead to a more or less metamorphic-appearing ontogenetic sequence.
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14

Flyachinskaya, L. P., and P. A. Lezin. "Larval and juvenile development of the Iceland cockle Ciliatocardium ciliatum (Fabricius, 1780) (Bivalvia: Cardiidae)." Proceedings of the Zoological Institute RAS 324, no. 2 (June 25, 2020): 242–51. http://dx.doi.org/10.31610/trudyzin/2020.324.2.242.

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The paper considers the development of Ciliatocardium ciliatum from the stage of straight hinge to juvenile. In the White Sea the spawning of C. ciliatum begins at the end of June, larvae at different stages of development occur in plankton until the end of September. The earliest of the larvae found had shell lengths of 123–130 µm. The paper first examined the anatomy and structure of the larval shell of C. ciliatum. During the development, the main stages of organogenesis were described and special attention was paid to the formation of the digestive and muscular systems. The digestive system begins to function when the larva reaches a size of 170–180 µm. The digestive gland has a two-blade shape and is shifted to the right side. The foot is formed at a size of 230 µm, the gill rudiments appear when the larva reaches 270 µm. The development of the larval shell and larval hinge of the mollusc is considered in detail. The development of the larval shell of C. ciliatum is similar to the development of other family members. Throughout all the larval stages, the shell has a rounded shape with a low umbos, and the prodissoconch II has a clearly visible concentric structure. The C. ciliatum larval hinge is characterized by weak differentiation and the absence of pronounced cardinal teeth typical for other Cardiidae. However, the lateral structures of the castle – ridges and flanges – are well developed. The ligament begins to form at a size of 240–250 µm and occupies a lateral position. The settlement of the cockle takes place in September in the subtidal zone. After the metamorphosis, a large radial sculpture is formed on the dissoconch and a number of small spikes are formed at the rib of the posterior shoulder.
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15

Heckford, R. J., and S. D. Beavan. "Coleophora arctostaphyli Meder, 1934 (Lepidoptera: Coleophoridae): observations on the early stages." Entomologist's Gazette 69, no. 2 (April 28, 2018): 115–18. http://dx.doi.org/10.31184/g00138894.692.1680.

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The ovum and larva of the case-bearing stage of Coleophora arctostaphyli Meder, 1934, are apparently undescribed, unlike the larva of the leaf-mining stage, larval case and biology. Descriptions of the ovum and final instar are provided but for reasons given in the text only a limited account is given of the final instar. We also record finding several mines on the foodplant, Arctostaphylos uva-ursi (L.) Spreng., containing dead larvae.
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16

Egan, EA, and DT Anderson. "Larval development of Elminius covertus Foster and Hexaminius popeiana Foster (Cirripedia : Archaeobalanidae : Elminiinae) reared in the laboratory." Marine and Freshwater Research 36, no. 3 (1985): 383. http://dx.doi.org/10.1071/mf9850383.

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The presence of embryos in the mantle cavity of E. covertus and H. popeiana has been monitored over a 2-year period. E. covertus has a clearly defined seasonal pattern with peak breeding during the winter and early spring. H. popeiana shows high levels of breeding activity throughout the year. The larval stages of E. covertus and H. popeiana are described from larvae reared in the laboratory. Morphological differences in each larval stage allow the larvae of the two species to be distinguished without difficulty. Differences between the larval stages of E. covertus and E. modestus are more minor, but are sufficient to distinguish most stages. Similarities in the larval morphology of the genera Elminius and Hexaminius support their inclusion in the subfamily Elminiinae. The larvae of H. popeiana also share features with the larvae of archaeobalanines, especially Conopea galeata.
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17

OROZCO, JESUS, and LUIS C. PARDO-LOCARNO. "Description of immature stages of three species of American Cetoniinae (Coleoptera: Scarabaeidae: Cetoniinae)." Zootaxa 769, no. 1 (December 14, 2004): 1. http://dx.doi.org/10.11646/zootaxa.769.1.1.

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The larvae and pupae of three Cetoniinae scarab beetles, Gymnetis pantherina Blanchard, 1837; Gymnetis holosericea (Voet, 1779), and Euphoria precaria Janson, 1881 from Colombia are described. Multiple color patterns of adults and key larval characters are illustrated for each species for the first time. The described larvae of Gymnetis MacLeay are included in a key to the larvae of the genus, now with five species; and Euphoria precaria is added to the extant key of the known Euphoria larvae. New distributional records for the country are presented and some comments on the biology of the species in captivity are provided.Se describe la larva y la pupa de tres escarabajos cetoninos: Gymnetis pantherina Blanchard, 1837; Gymnetis holosericea (Voet, 1779), y Euphoria precaria Janson, 1881 de Colombia. Los caracteres larvales estudiados y las multiples formas de coloraci n de los adultos de las especies tratadas son ilustrados por primera vez. Una clave para las larvas de las especies de Gymnetis descritas al momento es elaborada y la clave existente para las larvas de Euphoria es actualizada con la nueva informaci n. El rango distribucional de las especies en Colombia es ampliado con nuevos registros y se presenta informaci n sobre la biolog a de las especies en cautiverio.
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18

Kobayashi, K., R. M. Rompas, N. Imada, and Y. Oshima. "Mechanism of Abrupt Increase in Toxicity of Organophosphorothionates to Tiger Shrimp Larvae with Progress of Stages." Water Science and Technology 23, no. 1-3 (January 1, 1991): 487–96. http://dx.doi.org/10.2166/wst.1991.0448.

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To elucidate the cause of an abrupt increase in the toxicity of organophosphorus pesticides to tiger shrimp Penaeusjaponicus with the progress of larval stages, the toxicity of the pesticides to the shrimp larvae and the inhibition of larval acetylcholinesterase (AChE) by the pesticides, and the metabolism of fenitrothion(FS) in the larvae were studied at different stages, respectively. The toxicity of thiono-forms to the larvae increased abruptly with the progress of stages, whereas that of oxo-forms was unchanged from nauplius to postlarva. The susceptibility of larval AChE to each pesticide was almost unchanged in these stages. FS metabolic activity of zoea was very low, but the activity increased abruptly with their growth and resulted in the increase of fenitro-oxon which displays extremely high toxicity as compared with FS, i.e., the increase in the toxicity of thiono-forms to shrimp larvae with the progress of the stages must be due to the increase in the oxidative desulfuration activity.
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19

harizia, Abdelkader, Abdelkader Benguerai, and Yahia Boukhari. "Larvicidal activity of Bacillus Thuringiensis Kurstaki against Tuta Absoluta (Lepidoptera: Gelechiidae)." Lebanese Science Journal 20, no. 3 (December 27, 2019): 352–62. http://dx.doi.org/10.22453/lsj-020.3.352-362.

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A commercial formulation of Bacillus thurengiensis var Kurstaki (BTK) (IAB Bt) has been shown to be effective in controlling Tutaabsoluta Zeller larvae under laboratory conditions. Five concentrations are tested ((200, .350;500;650et800ppm)by ingestion, on the various larval stages (L1, L2, L3, L4 and L5). The larval mortality caused by BTK swelledwith increasing concentrations. The high concentrations of 650 and 800 ppm give 100% mortality rates for the early stages L1, L2, L3 and L4. Theacute toxicity (LC50) of BTK calculated for all larvae is 517 ppm. The lethal efficacy of BTK is noted 02 days, after the ingestion treatment, for the young stages (L1 and L2) and 04 at 6 days for the older larvae (L3 and L4) with a LT50, all larval stages combined equal to 2.6 days.
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20

Hudon, Christiane, and Pierre Fradette. "Wind-Induced Advection of Larval Decapods into Baie de Plaisance (Îles de la Madeleine, Québec)." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 7 (July 1, 1993): 1422–34. http://dx.doi.org/10.1139/f93-163.

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Abundance and spatial distribution of the larvae of the American lobster (Homarus americanus), the common rock crab (Cancer irroratus), and the toad crab (Hyas spp.), were monitored weekly during the summer of 1980 at a grid of 12 stations located in Baie de Plaisance. Following a period of winds ≥ 30 km∙h−1 shifting from the north to the southeast, large numbers of late-stage larvae of the three species were advected in the bay, concurrently with an intrusion of low-salinity water. Weekly abundances of consecutive larval stages were highly correlated, indicating that larvae tended to remain in the same water mass. Spatial association tended to be highest among the early stages within each species. The late larval stages of both lobster and rock crab behaved differently from the early stages with respect to light intensity and their horizontal distribution. Although the advection of water masses under the influence of wind events determines the overall abundance of larval decapods in Baie de Plaisance, larval behaviour (vertical migration and swimming ability) also affected distribution of older stage larvae but at a smaller scale. The dependence of advection on sporadic wind events occurring at the time of peak larval abundance reduces the chances of modelling yearly recruitment using average summer climatic conditions.
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21

Vijayasamundeeswari, Ayyathurai, Duraisamy Ladhalakshmi, Ambalavanan Sankaralingam, and Ramasamy Samiyappan. "Plant Growth Promoting Rhizobacteria of Cotton Affecting the Developmental Stages of Helicoverpa Armigera." Journal of Plant Protection Research 49, no. 3 (September 1, 2009): 239–43. http://dx.doi.org/10.2478/v10045-009-0036-y.

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Plant Growth Promoting Rhizobacteria of Cotton Affecting the Developmental Stages ofHelicoverpa ArmigeraRhizobacteria isolated from cotton roots exhibiting antagonism towards seedling blight and leaf blight of cotton were tested for their efficiency against the insect pest American bollworm (Helicoverpa armigera). The bioformulation developed usingBacillus subtilis(isolate DGL9) + chitin was found to be detrimental to the developmental stages ofH. armigera(larva, pupa and adult) by causing larval mortality, pupal and adult malformation with reduced adult emergence. Generally, the larvae exhibited antifeeding behaviour when fed on bolls collected from rhizobacterial treatments. Hence, the developmental stages were altered leading to early pupation. Further, the efficacy of the isolate DGL9 was confirmed by culturing the bacteria in a suitable medium and incorporating the cell suspension and supernatant obtained form the broth culture in larval diet. The larvae fed to the diet exhibited defective developmental stages which was more significant in case of diet incorporated with supernatant. The percentage of pupal malformation, adult emergence and adult malformation was high at 96 h of incubation with the supernatant.
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22

Rye, Leslie A., and Michael R. Baker. "The life history of Hysterothylacium analarum Rye and Baker, 1984 (Nematoda: Anisakidae) in Lepomis gibbosus (Pisces: Centrarchidae) in southern Ontario, Canada." Canadian Journal of Zoology 70, no. 8 (August 1, 1992): 1576–84. http://dx.doi.org/10.1139/z92-217.

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Larval stages of Hysterothylacium analarum are described from Lepomis gibbosus in Dawson Pond, Ontario (45°10′N, 78°50′W). Second-stage larvae were easily distinguished from all other stages by the presence of a conical boring tooth. Third-stage larvae lacked both a boring tooth and lips. Fourth-stage larvae had well-developed lips. The ratio of ventricular appendage length to intestinal caecum length varied greatly between larval stages and adults. Prevalence and intensity of larval stages and adult H. analarum showed a distinct seasonal pattern, with one generation of adult worms per year. In spring, third-stage larvae left nodules on the intestinal serosa of L. gibbosus and migrated to the intestinal lumen, where they rapidly moulted to the fourth-stage and then to adult worms. Eggs collected from gravid females developed to second stage larvae in approximately 5 days under laboratory conditions. In natural infections in the late summer second-stage larvae were found in nodules on the serosa and in the mesentery. Larvae apparently moulted to the third stage and overwintered in the nodules as third-stage larvae.
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Heckford, R. J., and S. D. Beavan. "Thisanotia chrysonuchella (Scopoli, 1763) (Lepidoptera: Crambidae): a review of the early stages." Entomologist's Gazette 71, no. 3 (July 31, 2020): 167–80. http://dx.doi.org/10.31184/g00138894.713.1771.

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An account is given of the ovum and larva of Thisanotia chrysonuchella (Scopoli, 1763) together with photographs of both, including the latter in various instars. Except for a description of the first instar, all other accounts of the larva in the British literature appear to be based on a German publication of 1865 that does not entirely agree with our observations. We review cited larval foodplants, all in the Poaceae, and set out our observations on larvae feeding on moss in captivity.
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24

Winch, Judith M., and J. Riley. "Studies on the behaviour, and development in fish, ofSubtriquetra subtriquetra: a uniquely free-living pentastomid larva from a crocodilian." Parasitology 93, no. 1 (August 1986): 81–98. http://dx.doi.org/10.1017/s0031182000049842.

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SUMMARYThe primary larva of the porocephalid pentastomidSubtriquetra subtriquetra, which infects the nasopharynx ofCaiman sclerops, is uniquely free-living. Eggs hatch within the nasal passages and the emergent larvae can remain infective to the fish intermediate host for 4–5 days. During this period larvae exhibit very stereotyped behaviour, alternating between a characteristic stationary ‘fishing’ posture and very brief periods of movement. Larval activity increases significantly at 3 days, probably effecting dispersal to a more favourable site for host invasion. Host location is passive and invading larvae penetrate to the swim-bladder where subsequent larval development, which involves 7 moults, occurs. All 8 larval stages are freely mobile in the swim-bladder and possess hooks. Sensilla, disposed in characteristic patterns, are present throughout development, increasing in number to the infective stage; the majority of sensilla are located on sensory papillae.
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25

Abrunhosa, Fernando A., Darlan J. B. Simith, Joely R. C. Monteiro, Antonio N. de Souza Junior, and Pedro A. C. Oliva. "Development and functional morphology of the larval foregut of two brachyuran species from Northern Brazil." Anais da Academia Brasileira de Ciências 83, no. 4 (October 21, 2011): 1269–78. http://dx.doi.org/10.1590/s0001-37652011005000045.

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Feeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory. During larval development, the foreguts of the larvae in the first and last zoeal stages and in the megalopa stage were microscopically examined, described and illustrated. The zoeal foreguts of both species were well developed, showing specialization with a functional cardiopyloric valve and a filter press. The megalopa stage had a complex and specialized gastric mill similar to that found in adult crabs with the appearance of rigidly calcified structures. These results support the hypothesis that the feeding behaviour of each larval stage is directly related to the morphological structure of the foregut. Such facts strongly indicate that all larval stages of both . vocator and P occidentalis need an external food source before completing the larval development in a planktonic environment.
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26

Duneau, David F., and Brian P. Lazzaro. "Persistence of an extracellular systemic infection across metamorphosis in a holometabolous insect." Biology Letters 14, no. 2 (February 2018): 20170771. http://dx.doi.org/10.1098/rsbl.2017.0771.

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Organisms with complex life cycles can differ markedly in their biology across developmental life stages. Consequently, distinct life stages can represent drastically different environments for parasites. This difference is especially striking with holometabolous insects, which have dramatically different larval and adult life stages, bridged by a complete metamorphosis. There is no a priori guarantee that a parasite infecting the larval stage would be able to persist into the adult stage. In fact, to our knowledge, transstadial transmission of extracellular pathogens has never been documented in a host that undergoes complete metamorphosis. We tested the hypothesis that a bacterial parasite originally sampled from an adult host could infect a larva, then survive through metamorphosis and persist into the adult stage. As a model, we infected the host Drosophila melanogaster with a horizontally transmitted, extracellular bacterial pathogen, Providencia rettgeri . We found that this natural pathogen survived systemic infection of larvae (L3) and successfully persisted into the adult host. We then discuss how it may be adaptive for bacteria to transverse life stages and even minimize virulence at the larval stage in order to benefit from adult dispersal.
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Rasmussen, Tone, and Michaela Aschan. "Larval stages ofPandalus borealis." Marine Biology Research 7, no. 2 (February 2011): 109–21. http://dx.doi.org/10.1080/17451001003764004.

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Tkachenko, O. V. "Eight Species of Anuran Amphibians (Amphibia, Anura) Found in Ukraine: Comparative Morphology and Classification of Larval Development Stages." Vestnik Zoologii 51, no. 4 (August 28, 2017): 343–48. http://dx.doi.org/10.1515/vzoo-2017-0039.

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Abstract Morphological characteristics typical for larval development stages of eight species of anuran amphibians found in Ukraine have been compared. Outer morphological features common for these species have been identified. Morphological features are suggested for determining the stages of larval development of various anuran amphibian’s species, as well as the numbering of the stages aft er the larvae exit from the spawn membranes.
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29

Journal, Baghdad Science. "The effect of Bacillus thuringiensis in Phthorimaea operculella (Zeller) (Lepetoptera:Gelechiidae)." Baghdad Science Journal 8, no. 1 (March 6, 2011): 7–12. http://dx.doi.org/10.21123/bsj.8.1.7-12.

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The following dilutions -710X46, -610X46, -510X46 of Bacillus thuringiensis were used for bioassay against the different larval instar of the potato tuber moth Phthorimaea operculella by the spraying method, the results showed that there was no significant influence in the percentage of egg hatching in comparison with the control. The sensitivity of larval stages was reduced with the increasing the age and exposure period. The study also showed that the larvae infected with B.t. stopped feeding, movement and a general paralysis causing the death of larva after (24-48) hours , and the larva color was changed from the natural waxy colour to brown finally to the black after death.
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30

Muratori, Frédéric, Jo Le Lannic, Jean-Pierre Nénon, and Thierry Hance. "Larval morphology and development of Aphidius rhopalosiphi (Hymenoptera: Braconidae: Aphidiinae)." Canadian Entomologist 136, no. 2 (April 2004): 169–80. http://dx.doi.org/10.4039/n03-057.

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AbstractThe aphid parasitoid Aphidius rhopalosiphi is the most abundant species of Aphidiinae in cereal fields in northern Europe. Although the larval morphology of other Aphidiinae has been described, the morphology and immature development of A. rhopalosiphi remain unknown. Our goal is to relate growth and larval developmental stages to morphological changes during parasitoid development, using light and scanning electron microscopy. Aphidius rhopalosiphi develops through three larval stages with clear differences in the morphology of the mouthparts, tegument sculpturing, and respiratory features that can be related to the different constraints that the larvae have to face. In the first instar, adaptations to physical combat with competitors take the form of strong mandibles, active caudae, and dorsal spines that allow crawling motion. In the third instar, the larva is adapted to tear tissues with short hooked mandibles and to face aerial respiration. All instars possess sensory structures. The "three instars" hypothesis is supported here by the observation of larvae in exuviation. No differences were found between our observations and descriptions of other Aphidius species, supporting the idea that species of this genus cannot be distinguished by larval morphology but only by morphometric analysis. Some new features of the genus are presented for the first and second instars.
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31

Hudon, Christiane, and Pierre Fradette. "Planktonic Growth of Larval Lobster (Homarus americanus) off îles de la Madeleine (Quebec), Gulf of St. Lawrence." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 5 (May 1, 1988): 868–78. http://dx.doi.org/10.1139/f88-105.

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The carapace length of the three planktonic larval and one postlarval stages of Homarus americanus was measured for larvae collected off îles de la Madeleine over three summers. Mean larval size did not vary between years or locations around the islands. The size of stages I and II remained constant throughout the summer, but after molting into stages III and IV, larvae diminished in size through the summer. Size frequency distribution became more scattered as larvae grew into more advanced stages. The increase of variance with size between stages I–IV followed the same progression as that observed between stages V–XIII, allowing prediction of the variance associated with mean size at each stage. The size of stage I larvae collected in nine regions along the Atlantic coast was not correlated with the July surface water temperature or with the smallest female size at maturity. Comparison of various body proportions suggested that a single morphometric measurement is not sufficient to describe geographical variations in size. Percentage growth per molt decreased with each successive molt. During summer, increment at molt decreased and molt frequency increased. Larval growth rates followed closely the temperature regime, with maximum growth rate attained during the warmest period of the summer (July 30 – August 9). The duration of the first three larval stages estimated from field data was of 24 d compared with 21 d calculated from previous laboratory studies. The maximum abundance of stage I larvae was synchronized with the period of most rapid increase in summer temperature, thus insuring that larvae achieved highest net growth rates through their planktonic phase.
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32

Priyadarshana, Tharaka Sudesh, and Ishara Harshajith Wijewardhane. "Lifecycle and fecula measurements of Cheritra freja (Lepidoptera: Lycaenidae), as relevant to the different larval stages." Journal of Threatened Taxa 9, no. 3 (March 26, 2017): 10011. http://dx.doi.org/10.11609/jott.1991.9.3.10011-10013.

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Here we present some hitherto undescribed details of the habitat, lifecycle, immature stages and a new method for finding different larval stages of Cheritra freja by analyzing the fecula measurements of various larval instars. This study should be very useful in helping researchers to find larvae and new food plants.
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33

Pedersen, Eric J., Ryan R. E. Stanley, Paul V. R. Snelgrove, and Frédéric Guichard. "Experimental evidence for concentration-dependence and intraspecific variation of movement behaviour in American lobster (Homarus americanus) larvae." Canadian Journal of Zoology 95, no. 10 (October 2017): 759–70. http://dx.doi.org/10.1139/cjz-2016-0100.

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Predicting dispersal paths of marine larvae with extended pelagic durations, such as American lobster (Homarus americanus H. Milne Edwards, 1837), requires understanding the cues to which larvae respond, and how that response reflects changes in larval behaviour. If larvae respond to conspecific presence by varying their movement, then this behaviour can bias laboratory estimates of environmental responses. We tested whether larvae actively decreased their local intraspecific density by measuring how the vertical distribution of larvae changed under high versus low concentrations of conspecifics. We observed weak increases in vertical dispersion at higher concentrations both in newly hatched larvae and in postlarvae, but not in intermediate larval stages. We also tested for differences in horizontal swimming behaviour in high and low concentrations, by fitting a novel random walk model that allowed us to model both larval interactions and persistent turning behaviours. We showed substantial reduction in diffusive behaviour under high concentration conditions resulting from more frequent turns by each larva, but no evidence for consistent avoidance of conspecifics. Our study is the first to demonstrate concentration-dependent behaviours in lobster larvae.
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CARVALHO, Thaís Billalba, Ellen Cristina Monteiro de SOUZA, Jaquelinne PINHEIRO-DA-SILVA, and Marle Angélica VILLACORTA-CORREA. "Effect of body size heterogeneity on the aggressive behavior of larvae of matrinxã, Brycon amazonicus (Characiformes, Bryconidae)." Acta Amazonica 48, no. 4 (December 2018): 304–10. http://dx.doi.org/10.1590/1809-4392201800541.

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ABSTRACT Brycon amazonicus is a native Amazonian fish that is important for aquaculture in South America. Larval mortality is high in this species in intensive breeding systems due to aggressiveness among larvae. The present study investigated experimentally the effects of body size heterogeneity on the aggressive behavior and survival of B. amazonicus during the early stages of larval development. Two treatments (larvae groups with homogeneous and heterogeneous body size) were evaluated throughout early larval stages tested at six time points: 12, 24, 36, 48, 60 and 72 hours after hatching (HAH). Two experiments quantified, respectively, aggressive interactions and mortality rates among larvae at each time point. The frequency of aggressive interactions exhibited by the less aggressive larvae in each replicate was higher in the homogeneous size treatment. Aggressiveness was higher at 12 HAH, decreasing thereafter, and increasing again at 72 HAH. The mortality rate significantly increased with the larval stage, and was higher in the homogeneous than in the heterogeneous sized groups. Our results showed that aggressiveness in B. amazonicus larvae is affected by size variability and larval development stage. This knowledge about larval behavior is important to develop measures to improve larval health and survival in intensive production systems for this species.
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35

Benítez, Sergio A., Thomas M. Iliffe, Salvador Martínez, Juan Carlos Ojeda, José Luis Villalobos, and Fernando Alvarez. "Larval development of the stygobitic shrimp Creaseria morleyi (Creaser, 1936) (Decapoda: Caridea: Palaemonidae) from the Yucatán Peninsula, Mexico." Journal of Crustacean Biology 40, no. 3 (February 20, 2020): 221–29. http://dx.doi.org/10.1093/jcbiol/ruaa006.

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Abstract Although the larval development of epigean palaemonid shrimps has been studied extensively, only a few investigations deal with stygobitic species. We present the larval development of the cave-adapted Creaseria morleyi (Creaser, 1936) from anchialine caves in the Tulum area, Quintana Roo, Yucatán Peninsula, Mexico. Through the discovery of a series of larvae at different stages of development, we constructed a sequence extending through the juvenile stage. The larvae (41) were captured in plankton tows above the halocline at depths ranging between 11 and 15 m during eight surveys conducted between 2013 and 2016. Six larval stages and the first juvenile were identified; however, it is clear from the gradual modification of structures and appendages that more stages exist. The first larvae have a large quantity of vitellum and do not feed, since they have only rudimentary, and possibly non-functional, mouthparts. In the sixth stage and the juvenile, when the stages have no vitellum left, the mouthparts, chelae, and pleopods develop entirely. A comparison with other palaemonid shrimps suggests that C. morleyi has a greater affinity with those palaemonid species possessing extended larval development as is seen in species of MacrobrachiumSpence Bate, 1868.
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36

ANASTASIADOU, CHRYSSA, ALEXANDROS NTAKIS, and IOANNIS D. LEONARDOS. "Larval development of the freshwater shrimp Atyaephyra desmarestii (Millet, 1831) sensu lato (Decapoda: Caridea: Atyidae) and morphological maturation from juveniles to adults." Zootaxa 2877, no. 1 (May 13, 2011): 41. http://dx.doi.org/10.11646/zootaxa.2877.1.2.

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A complete serial of larval staging of Atyaephyra desmarestii (Millet, 1831) sensu lato from Louros River (north-western Greece) was obtained in the laboratory and described in detail. Thirty berried females were collected and transferred to an aquarium containing water and vegetation from the sampling site. The newly hatched larvae were transferred into small sterile aquaria and mass cultured. After each moult, several larvae were photographed and preserved with their exuviae. The reared larvae of A. desmarestii sensu lato passed through six zoeal stages and one megalopal stage. At the experimental conditions, the durations of each larval stage were as follows: three days for the 1 st larval stage; three to four days for 2 nd larval stage; six to eight days for 3 rd ; seven to nine days for 4 th ; nine to ten days for 5 th , 6 th and megalopal stages. All the obtained stages were described in detail. The larval morphological characters of the described material and the larvae specimens collected from natural populations were compared with the literature data on closely related species. Morphological description of the different phases for juveniles, immature, female and male mature individuals of A. desmarestii sensu lato are also presented in detail.
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37

Kapila, Rohit, Mayank Kashyap, Soumyadip Poddar, Shreya Gangwal, and N. G. G. Prasad. "Evolution of pathogen-specific improved survivorship post-infection in populations of Drosophila melanogaster adapted to larval crowding." PLOS ONE 16, no. 4 (April 14, 2021): e0250055. http://dx.doi.org/10.1371/journal.pone.0250055.

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The environment experienced by individuals during their juvenile stages has an impact on their adult stages. In holometabolous insects like Drosophila melanogaster, most of the resource acquisition for adult stages happens during the larval stages. Larval-crowding is a stressful environment, which exposes the larvae to scarcity of food and accumulation of toxic waste. Since adult traits are contingent upon larval stages, in larval-crowding like conditions, adult traits are prone to get affected. While the effect of resource limited, poor-developmental environment on adult immune response has been widely studied, the effect of adaptation to resource-limited developmental environment has not been studied, therefore in this study we assayed the evolution of ability to survive infection in adult stages as a correlated response to adaptation to larval crowding environments. Using four populations of Drosophila melanogaster adapted to larval crowding for 240 generations and their respective control populations, we show that populations adapted to larval crowding show an improved and evolved post-infection survivorship against a gram-negative bacteria Pseudomonas entomophila. Whereas, against a gram-positive bacteria Enterococcus faecalis, no difference in post-infection survivorship was observed across control and selected populations. In this study, we report the co-related evolution of pathogen-specific increased survivorship post-infection in populations of Drosophila melanogaster as a result of adaptation to larval crowding environment.
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38

Rodrigues-Galdino, Alana Marielle, Camila Valente Maiolino, Mariana Forgati, Lucélia Donatti, Jorge Daniel Mikos, Paulo César Falanghe Carneiro, and Flavia Sant'Anna Rios. "Development of the neotropical catfish Rhamdia quelen (Siluriformes, Heptapteridae) incubated in different temperature regimes." Zygote 18, no. 2 (October 27, 2009): 131–44. http://dx.doi.org/10.1017/s096719940999013x.

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SummaryThe developmental stages for the embryonic and larval periods of the silver catfish (Rhamdia quelen) kept at different temperatures (21, 24, 27 and 30°C) are described. Fish were analysed under light and scanning electron microscopy. For embryonic development, we described 25 stages, which were grouped into seven periods named zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching periods. For larval development, we defined three stages (early, mid, and late larvae). Additionally, the main ontogenetic events during the post-larvae and early juvenile periods were also described. This species presents a well developped lateral line and chemosensory systems that grow up during the larval period, maturing in the post-larvae. All tested temperatures are viable to R. quelen development, but a shorter incubation period was necessary to complete the development at lower temperatures. However, some malformations (heart edema) were verified at 30°C.
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39

Marco-Herrero, Elena, Klaus Anger, and Liliam Hayd. "Extended larval development in the hololimnetic shrimp Macrobrachium pantanalense (Decapoda, Palaemonidae) reared in the laboratory." Crustaceana 92, no. 6 (May 31, 2019): 693–723. http://dx.doi.org/10.1163/15685403-00003899.

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Abstract The postembryonic development of Macrobrachium pantanalense, a freshwater shrimp from central South America, was experimentally studied in the laboratory. In contrast to most other hololimnetic Caridea, this species passes through an extended larval phase with intraspecific variability in the number and morphology of stages. Here we describe the shortest developmental pathway comprising nine zoeal stages, the first post-zoeal stage (morphologically transitional between a late larva and an early juvenile), and an early juvenile with vestiges of larval traits. Post-zoeal development is characterized by a gradual reduction of the natatory exopods of the pereiopods (a larval character) and a concurrent transformation of the endopods to walking legs (juvenile trait). A comparison with the larvae of a closely related, often confused estuarine species from northern South America, M. amazonicum, revealed consistent interspecific differences, especially in the morphology of the fifth pereiopod, allowing for an unambiguous distinction of these two allopatric congeners.
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40

LIU, RONGSONG, GERGELY RÖST, and STEPHEN A. GOURLEY. "Age-dependent intra-specific competition in pre-adult life stages and its effects on adult population dynamics." European Journal of Applied Mathematics 27, no. 1 (August 12, 2015): 131–56. http://dx.doi.org/10.1017/s0956792515000418.

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Intra-specific competition in insect and amphibian species is often experienced in completely different ways in their distinct life stages. Competition among larvae is important because it can impact on adult traits that affect disease transmission, yet mathematical models often ignore larval competition. We present two models of larval competition in the form of delay differential equations for the adult population derived from age-structured models that include larval competition. We present a simple prototype equation that models larval competition in a simplistic way. Recognising that individual larvae experience competition from other larvae at various stages of development, we then derive a more complex equation containing an integral with a kernel that quantifies the competitive effect of larvae of ageāon larvae of agea. In some parameter regimes, this model and the famous spruce budworm model have similar dynamics, with the possibility of multiple co-existing equilibria. Results on boundedness and persistence are also proved.
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41

Grioche, A., P. Koubbi, X. Harlay, and B. Sautour. "Sole larval distribution (Solea solea) in the eastern English Channel and Southern Bight of the North Sea." Journal of the Marine Biological Association of the United Kingdom 81, no. 4 (August 2001): 673–78. http://dx.doi.org/10.1017/s0025315401004350.

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The distribution of sole (Solea solea) eggs and larvae were described from two cruises conducted in April and May 1995 along the French coast of the eastern English Channel and the Belgian coast of the Southern Bight of the North Sea. Sole migration was investigated using larval stages and univariate spatial analysis as geostatistics (variograms). Important environmental parameters were selected by comparison with larval distribution. Path analysis was used to remove spatial correlation and to define links between abundance and environmental variables. Sole larvae were found to be coastal throughout their development. Strong links between larval distribution and environmental parameters were identified, particularly for the younger stages which were found in higher abundance in areas of high chlorophyll-a concentration. The association was not direct, suggesting that the larval spatial distribution was influenced by an undetermined, intermediate variable, such as larval prey. Sole larvae are retained in the coastal area throughout ontogeny despite the strong hydrodynamics which characterize the region. Larval distribution resulted from behavioural mechanisms as well as environmental influences.
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42

Baranov, Viktor A., Mario Schädel, and Joachim T. Haug. "Fly palaeo-evo-devo: immature stages of bibionomorphan dipterans in Baltic and Bitterfeld amber." PeerJ 7 (October 9, 2019): e7843. http://dx.doi.org/10.7717/peerj.7843.

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Larvae of flies and gnats (Diptera) form a crucial component of many terrestrial and freshwater ecosystems in the extant biosphere. Larvae of Diptera play a central role in water purification, matter and energy transfer in riparian ecosystems in rivers, carbon cycling in lakes and forests as well as being major decomposers of dead organic matter. Despite all these important roles, dipteran larvae are most often ignored in palaeoecological studies, due to the difficulty of the taxonomic identification of fossil larvae, but also due to the perceived importance of adult dipterans in palaeoentomological and taxonomic studies. Despite that, much information on palaeoecosystems can be gained from studying fossil dipteran larvae, in particular for well preserved specimens from fossil resins (ambers and copals). Since ambers are selectively preserving fauna of trunks and leaf litter, it allows us to learn a lot about xylophages and saprophages of amber forests, such as Eocene Baltic amber forest. Here we present immature stages (larvae and pupae) of the dipteran ingroup Bibionomorpha, from Baltic and Bitterfeld amber forests. We have recorded at least four different larval morphotypes, one with four distinct instars, and at least three pupal morphotypes. One larva is recognised as a new species and can be interpreted either as a representative of a highly derived ingroup of Bibionidae or as a sister species to Bibionidae. Also represented by single larval specimens are the groups Pachyneura (Pachyneuridae) and Sylvicola (Anisopodidae). The majority of the recorded specimens are representatives of the group Mycetobia (Anisopodidae). Due to the abundance of immature stages of Mycetobia, we have been able to reconstruct the number of larval stages (4) and relative growth rate of these fossil dipterans. We discuss implications of these finds.
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43

Ren, Qilin, Muhammad Haseeb, Jingyu Fan, Pengxiang Wu, Tianqi Tian, and Runzhi Zhang. "Functional Response and Intraspecific Competition in the Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae)." Insects 11, no. 11 (November 16, 2020): 806. http://dx.doi.org/10.3390/insects11110806.

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Functional responses of the fall armyworm (FAW) larvae at each stage, and their intraspecific competition associated with cannibalism, provide insights into developing pest management strategies for the FAW. To help use insecticides more sparingly, the functional response and intraspecific competition of the FAW larvae were evaluated under the laboratory conditions. The results showed that all stages of the FAW larvae displayed a type II functional response to diet. Based on Holling’s disc equation, the search rate (a) and handling time (Th) of sixth instar larvae (a = 0.493; Th = 0.37 min) were the highest, and the shortest of all larval stages, respectively. Intraspecific competition curves fitted the data for fourth to sixth larval stages of the FAW, and the coefficient of intraspecific competition (m) assessed by the intraspecific competition equation were highest for fifth instar larvae (m = 0.48). The present study indicates that 5th and 6th instar larvae can cause the most plant damage (accounted for 88.9% of larval consumption), and these stages should be the focus of any pest management strategy. Intraspecific competition, especially cannibalism, impacts the feeding patterns of the FAW larvae and needs close attention. Understanding the functional response and intraspecific competition of the FAW larvae contributes greatly to practical applications of insecticides, increasing the effectiveness of chemical sprays and decreasing ecological damage.
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44

Zhu, Guan-Heng, Yaoyu Jiao, Shankar C. R. R. Chereddy, Mi Young Noh, and Subba Reddy Palli. "Knockout of juvenile hormone receptor, Methoprene-tolerant, induces black larval phenotype in the yellow fever mosquito, Aedes aegypti." Proceedings of the National Academy of Sciences 116, no. 43 (September 30, 2019): 21501–7. http://dx.doi.org/10.1073/pnas.1905729116.

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The yellow fever mosquito, Aedes aegypti, vectors human pathogens. Juvenile hormones (JH) control almost every aspect of an insect’s life, and JH analogs are currently used to control mosquito larvae. Since RNA interference does not work efficiently during the larval stages of this insect, JH regulation of larval development and mode of action of JH analogs are not well studied. To overcome this limitation, we used a multiple single guide RNA-based CRISPR/Cas9 genome-editing method to knockout the methoprene-tolerant (Met) gene coding for a JH receptor. The Met knockout larvae exhibited a black larval phenotype during the L3 (third instar larvae) and L4 (fourth instar larvae) stages and died before pupation. However, Met knockout did not affect embryonic development or the L1 and L2 stages. Microscopy studies revealed the precocious synthesis of a dark pupal cuticle during the L3 and L4 stages. Gene expression analysis showed that Krüppel homolog 1, a key transcription factor in JH action, was down-regulated, but genes coding for proteins involved in melanization, pupal and adult cuticle synthesis, and blood meal digestion in adults were up-regulated in L4 Met mutants. These data suggest that, during the L3 and L4 stages, Met mediates JH suppression of pupal/adult genes involved in the synthesis and melanization of the cuticle and blood meal digestion. These results help to advance our knowledge of JH regulation of larval development and the mode of action of JH analogs in Ae. aegypti.
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45

León, Roxana, Leonardo R. Castro, and Mario Cáceres. "Dispersal of Munida gregaria (Decapoda: Galatheidae) larvae in Patagonian channels of southern Chile." ICES Journal of Marine Science 65, no. 7 (June 16, 2008): 1131–43. http://dx.doi.org/10.1093/icesjms/fsn093.

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Abstract León, R., Castro, L. R., and Cáceres, M. 2008. Dispersal of Munida gregaria (Decapoda: Galatheidae) larvae in Patagonian channels of southern Chile. – ICES Journal of Marine Science, 65: 1131–1143. The dispersal of Munida gregaria larvae in Chilean Patagonian channels was assessed in spring 2002 and 2003, and winter 2003. In winter 2003, zoea I was the most abundant stage in all channels and there were no larval stages older than zoea IV. In spring 2002 and 2003, there were six larval stages in all channels, and the greater abundance of older larvae suggested that reproduction takes place in winter and larval development in spring. Further, analysis of spatial distribution by stage revealed that early zoeae moved seawards. Generalized Additive Models analyses showed that most larval stages were temperature-dependent, and that the salinity range of the youngest zoea was wider than that of older larvae and post-larvae, coinciding with an ontogenetic distribution change from estuary to shelf. Residual flows determined with an acoustic Doppler current profiler revealed two layers of opposite flow: the shallowest layer moved seawards and the deeper layer onshore. The surface layer was wider in spring than in winter because of seasonal increase in fresh-water input. The dispersal pattern of M. gregaria consisted of an inner channel larval release in winter, followed by an along-channel larval drift and subsequent export to the shelf in spring. The mechanism by which juveniles return to the channels seemed to be associated with the onshore subsurface flow.
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46

Webb, C. M. "Post-Larval Development of the Tellinacean Bivalves Abra Alba, Tellina Fabula and Donax Vittatus (Mollusca: Bivalvia), With Reference to the Late Larva." Journal of the Marine Biological Association of the United Kingdom 66, no. 3 (August 1986): 749–62. http://dx.doi.org/10.1017/s0025315400042338.

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The post-larval shell and hinge development of the bivalves Abra alba (Wood), Tellina fabula Gmelin and Donax vittatus (da Costa) from the recently metamorphosed size to a juvenile size of 1·2–1·4 mm shell length has been examined using scanning electron microscopy. Early post-larval development in the stages up to 1·0–1·2 mm size can involve considerable morphogenetic change and requires careful description with photographic developmental series. The form of the pediveliger larva is present in the early post-larval shell and confirms the identity of the larvae of A. alba and T. fabula. The veliger and pediveliger larvae of A. alba are described. The similar larval form of the tellinacean bivalves is modified by differential margin growth early in post-larval development. Comparison of these bivalves with allied species reveals that the post-larvae are distinguishable at even the smallest sizes by the shell and hinge form. The metamorphic size of A. alba ranges from 0·26 to 0·31 mm, of T. fabula from 0·25 to 0·28 mm and of D. vittatus from 0·25 to 0·35 mm. The bivalve post-larvae were collected from the shallow sublittoral of Oxwich Bay, Bristol Channel, U.K., and the larvae from the overlying waters, during the years 1980–2.
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47

SCHMIDT, ROBERT E., and ROBERT A. DANIELS. "Description of the larval stages of the Shield Darter, Percina peltata (Pisces: Percidae), in New York." Zootaxa 774, no. 1 (December 17, 2004): 1. http://dx.doi.org/10.11646/zootaxa.774.

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A series of larvae of Percina peltata (Pisces: Percidae) was collected from the Neversink River, a Delaware River tributary, in spring of 2001 and 2002. We provide descriptions and illustrations of yolk sac larvae and post yolk sac larvae through the end of larval development. The larval morphology of P. peltata is plesiomorphic for the clade of the Etheostomatinae which we correlate with the plesiomorphic position afforded P. peltata in other studies. We do not consider the larval morphology of this species to be an adaptation to its environment.
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48

Kalesaran, Ockstan J. "PEMELIHARAAN POST LARVA (PL4-PL9) UDANG VANNAMEI (Penaeus vannamei) DI HATCHERY PT. BANGGAI SENTRAL SHRIMP PROVINSI SULAWESI TENGAH." JURNAL PERIKANAN DAN KELAUTAN TROPIS 6, no. 1 (April 30, 2010): 58. http://dx.doi.org/10.35800/jpkt.6.1.2010.121.

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White shrimp culture have been developed in some part of brackish water pond area in Indonesia, either in extensive, semi intensive or intensive technology and it resulted increasing on Indonesian shrimp culture production. At post larval stages, the pleopods become fully developed and functional. The animals grow very fast in terms of size and are able to swim freely although early post larvae are still planktonic. This research was done to know post larval rearing in Hatchery of PT. Banggai Sentral Shrimp. Preparation of basic facilities such as larval rearing tanks, water supply and aeration system is one of the most important activities in hatchery operation. Good water quality should be strictly maintained especially during this phase of larva rearing.
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49

Critchlow, Justin T., Adriana Norris, and Ann T. Tate. "The legacy of larval infection on immunological dynamics over metamorphosis." Philosophical Transactions of the Royal Society B: Biological Sciences 374, no. 1783 (August 26, 2019): 20190066. http://dx.doi.org/10.1098/rstb.2019.0066.

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Insect metamorphosis promotes the exploration of different ecological niches, as well as exposure to different parasites, across life stages. Adaptation should favour immune responses that are tailored to specific microbial threats, with the potential for metamorphosis to decouple the underlying genetic or physiological basis of immune responses in each stage. However, we do not have a good understanding of how early-life exposure to parasites influences immune responses in subsequent life stages. Is there a developmental legacy of larval infection in holometabolous insect hosts? To address this question, we exposed flour beetle ( Tribolium castaneum ) larvae to a protozoan parasite that inhabits the midgut of larvae and adults despite clearance during metamorphosis. We quantified the expression of relevant immune genes in the gut and whole body of exposed and unexposed individuals during the larval, pupal and adult stages. Our results suggest that parasite exposure induces the differential expression of several immune genes in the larval stage that persist into subsequent stages. We also demonstrate that immune gene expression covariance is partially decoupled among tissues and life stages. These results suggest that larval infection can leave a lasting imprint on immune phenotypes, with implications for the evolution of metamorphosis and immune systems. This article is part of the theme issue ‘The evolution of complete metamorphosis'.
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50

Pattirane, Chrisoetanto P., and Bethzy J. Pattiasina. "Morphology Characteristic, Growth And Survival Rate Of The Early Larval Stages Of Mud Crab, Scylla serrata (Forsskal, 1775) For The Rearing Process." Jurnal Ilmiah PLATAX 8, no. 1 (May 27, 2020): 140. http://dx.doi.org/10.35800/jip.8.1.2020.28597.

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The availability of female adult mature will continuously support mud crab hatchery to produce the best quality of larvae. Bray et al., (1990b) proposed that zoea length can be used as an index of larval quality. Larval quality is dependent on the physiology condition related to the growth and survival rate of several larval development stages (Racotta et al., 2003). The mortality in all development stages was due to the high sensitivity of larvae for the environment changes. Two aquariums and sterilized water were used in all rearing process and larvae of Scylla serrata fed once a day. It was fed by rotifer (Branchionus plicatilis) and Artemia sp on the third and fifth days. The results showed that the eye was a distinguishing characteristic between zoea I and zoea II. Development of zoea I range about 0 (zero) to fourth days and zoea II about fifth to seventh days. Observation of growth for six days indicate an increasing significantly on the fourth to sixth days. The survival rate of Scylla serrata larvae without food holds three days out. Otherwise, larvae that were fed on everyday hold seven days out. ABSTRAKKetersediaan induk yang matang telur secara berkesinambungan akan sangat mendukung usaha pembenihan kepiting bakau dalam menghasilkan larva dengan kualitas yang baik. Bray et al., (1990b) bahwa panjang zoea dapat digunakan sebagai suatu indeks kualitas larva. Selain itu, kualitas larva juga bergantung kepada kondisi fisiologis larva dan berkaitan dengan rata-rata pertumbuhan dan sintasan selama beberapa tahapan larva (Racotta et al., 2003). Seluruh proses pemeliharaan digunakan air steril dengan menggunakan wadah berupa akuarium sebanyak dua buah. Larva kepiting bakau, S. serrata selama pemeliharaan diberi pakan satu kali sehari. Pakan yang diberikan berupa rotifer (Branchionus plicatilis) dan artemia pada hari kelima dan ketiga. Hasil penelitian menunjukkan bahwa ciri morfologi pembeda antara tahap zoea I dan zoea II adalah mata. Perkembangan zoea I berkisar antara hari 0 sampai dengan hari 4 selanjutnya zoea II antara hari kelima sampai hari ketujuh. Pertumbuhan yang diamati selama masa pemeliharaan hari pertama sampai hari keenam, menunjukkan adanya peningkatan yang signifikan pada hari keempat sampai hari keenam. Tingkat kelangsungan hidup larva S. serrata yang tidak diberi pakan dapat bertahan mencapai tiga hari. Sebaliknya untuk larva yang diberi pakan selama masa pemeliharaan mampu bertahan hingga mencapai tujuh hari.Kata kunci: Larva zoea, Scylla serrata, pertumbuhan, tingkat kelangsungan hidup
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