Dissertations / Theses on the topic 'Phenacoccus'

Comme d'autres Homoptères, Phenacoccus manihoti est un insecte principalement phloémophage. L'utilisation, pour la première fois sur une cochenille, de l'électrographie de pénétration -EPG- a permis de révéler et de quantifier les interactions pré-phloémiennes entre les stylets de l'insecte et les tissus de la plante. Sur une gamme d'hôtes naturels (Manihot) et de substitution (Talinum, Poinsettia), un comportement de rejet précoce, dû aux délais et obstacles à atteindre le phloème, a été mis en évidence. Une analyse de certaines substances secondaires des liquides foliaires des hôtes a permis de préciser que les composés cyanés et les acides phénoliques du mésophylle seraient plus particulièrement impliqués dans les mécanismes de fixation de P. Manihoti sur la plante. Les flavonoïdes ne semblent pas intervenir dans celle phase précoce. Nous avons ensuite précisé le rôle des composés allélo-chimiques dans la relation d'antibiose du manioc sur la cochenille. Il s'est avéré que les glucosides cyanogéniques, transportés par la sève phloémienne, ont plus probablement un rôle phago-stimulant que toxique, alors que la rutine, flavonoïde glycosylé également trans-loqué, pourrait affecter le développement de P. Manihoti. Des expérimentations au champ et au laboratoire ont permis de déceler une réponse défensive du manioc contre l'attaque de la cochenille, se traduisant par une augmentation de la teneur en rutine lors de l'infestation, notamment chez les génotypes les moins favorables à P. Manihoti. Cette réponse est variable et dépend notamment du facteur saisonnier: elle s'amoindrit en saison sèche, à la fin de laquelle sont souvent observées sur le terrain les pullulations de la cochenille
As do other Homopterous insects, Phenacoccus manihoti feeds mainly on phloem sap. The use of electrical penetration graphs -EPG -, for the first time on a mealy-bug, shows that pre-phloem interactions between the insect sytles and the plant tissues are an important step for the host-plant acceptation. Precocious plant rejection due to delays in phloem finding may result in global "antixenosis". A chemical analysis of some secondary plant compounds in leaves of host plants and substitue plants revealed that cyanide compounds and phenolic acids, as opposed to flavonoids, were mainly correlated with host recognition by P. Manihoti. We tryed to specify the action of allelo-chemical compounds present in the phloem sap. The cyanogen glucosides (linamarin and lotaustralin in Cassava) seem to play a phagostimulatory (vs toxic) function, while rutin is likely to induce some inhibiting role in the development of the insect. Field and laboratory experiments showed the occurence of a putative defensive response of cassava against meyly-bug, which displayed significant increases in rutin levels with infestation, especially with the less favourable genotypes. This induced response clearly depended mainly on seasonal factor. It decreased in the dry season, at the end of which most population increases could be observed in field conditions

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia / UL
O objetivo deste trabalho foi estudar a dinâmica de infestação de Phenacoccus madeirensis em cafeeiro, em estufa, e sua interação com o parasitoide Anagyrus amnestos. Procedeu-se à monitorização de cochonilhas-algodão, numa estufa do Centro de Investigação de Ferrugens do Cafeeiro, em Oeiras, entre setembro de 2016 e novembro de 2017. Foram colhidas amostras para determinação da taxa de parasitismo, por A. amnestos. A especificidade do parasitoide foi estudada, através de ensaios biológicos, sem escolha, em placa de Petri, expondo, durante períodos de 30 minutos, uma fêmea do parasitoide, previamente fecundada, a 10 fêmeas jovens ou 3º instares de uma de três espécies de cochonilhas-algodão: P. madeirensis, Planococcus ficus (Signoret) e Pseudococcus calceolariae (Maskell). Foram realizadas 40 repetições. A percentagem de plantas infestadas variou entre 0,6% e 56,9%. Foram identificadas três espécies de cochonilhas-algodão: Planococcus citri (Risso), P. madeirensis e Pseudococcus longispinus (Targioni Tozzetti). Planococcus citri foi a espécie mais frequente. Phenacoccus madeirensis foi a segunda espécie mais frequente. A taxa de parasitismo por A. amnestos variou entre 1% e 100%, com um valor médio de 19%. Anagyrus amnestos só parasitou P. madeirensis, tendo rejeitado como hospedeiros P. ficus e P. calceolariae. A proporção do tempo de procura do parasitoide representou cerca de 47%, no caso de P. madeirensis, em comparação com mais de 80%, em P. ficus e P. calceolariae. A percentagem de tempo de antenação também permite diferenciar a espécie hospedeira. No caso de P. madeirensis, este comportamento (6,5%) representou cerca de três a quatro vezes mais a percentagem de tempo alocado pelo parasitoide no caso da interação com P. calceolariae (2,1%) e P. ficus (1,5%), respetivamente
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Cotton crop has been well known to man since ancient times, but one of the main problems of this culture is the attack of pests. Phenacoccus solenopsis Tinsley (Hemiptera:Pseudococcidae) has a high morphological diversity, biological adaptations and ecological adjustments that give this species a high capacity to feed host plants. Chemical control is the main method used to control population outbreaks of this mealybug. However, it is difficult to fully control this mealybug with conventional insecticides because of the waxy material that covers the bodies of adult females. The objective of this research was to study the biological aspects of P. solenopsis in cotton leaf discs with and without kaolin. Kaolin is a white clay mineral with various agricultural applications. The film of kaolin particles creates a physical or mechanical barrier of protection against arthropods and pathogens. The work was carried out in the Embrapa Algodão Entomology Laboratory, Campina Grande, State of Paraíba, Brazil, in climatic chamber of type B.O.D. (Biochemical Oxygen Demand), adjusted to a temperature of 25 ± 1 °C, relative humidity of 60 ± 10% and photophase of 12 hours. The experimental design was completely randomized with two treatments and fifty replicates. The treatments consisted of spraying the immature and newly emerged adult stages of P. solenopsis and immersing cotton leaf discs in kaolin suspension (with kaolin) in distilled -1 water at 60 gL the immature stages of P. solenopsis were determined and, in the adult phase, the periods of or in distilled water (control, without kaolin). The duration and survival of pre-oviposition, oviposition, post-oviposition, longevity, fecundity, number of eggs/day, number of eggs/female/day. The parameters of the fertility and life expectancy tables of P. solenopsis were also estimated to determine the population growth potential of this mealybug in both treatments. The results obtained in this research demonstrate that the survival of the immature stages of P. solenopsis in cotton leaves disks was not affected by kaolin. However, it was observed a shorter duration of development of the second and third instars and of the egg period to the adults of P. solenopsis females in the treatment with kaolin suspension and a longer period of oviposition, fecundity and number of eggs per female in that same treatment. In addition, the shortest time required for the P. solenopsis population to double time (TD) associated with the highest values of gross (TBR) and net reproductive rate (Ro), intrinsic (rm) and finite rates of increase (λ), survival, specific fertility (mx), reproductive value (VRx) and life expectancy (ex) in treatment with kaolin suspension indicate that spraying of this product on cotton plants infested by mealybug should be avoided because they favor its growth populational.
A cultura do algodão é bem conhecida do homem desde antiguidade, porém um dos principais problemas dessa a cultura é o ataque de pragas. A cochonilha Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) apresenta uma grande diversidade morfológica, adaptações biológicas e ajustes ecológicos que conferem a essa espécie uma alta capacidade de se alimentar de plantas hospedeiras. O controle químico é o principal método empregado para controlar os surtos populacionais dessa cochonilha. No entanto, é difícil controlar plenamente essa cochonilha com inseticidas convencionais, devido ao material ceroso que recobre os corpos das fêmeas adultas. O objetivo deste trabalho foi estudar os aspectos biológicos de P. solenopsis em discos de folhas de algodão com e sem caulim. O caulim é um mineral de argila branca com diversas aplicações agrícolas. O filme de partículas de caulim cria uma barreira física ou mecânica de proteção contra os artrópodes e patógenos. O trabalho foi conduzido no Laboratório de Entomologia da Embrapa Algodão, município de Campina Grande, Estado da Paraíba, Brasil, em câmaras climatizadas do tipo B.O.D. (Biochemical Oxygen Demand), ajustadas para à temperatura de 25 ± 1 ºC, umidade relativa de 60 ± 10% e fotofase de 12 horas. O delineamento experimental foi inteiramente casualizado com dois tratamentos e cinquenta repetições. Os tratamentos consistiram da pulverização dos estágios imaturos e adultos recém-emergidos de P. solenopsis e da imersão dos discos de folhas de -1 algodoeiro em suspensão de caulim (com caulim) em água destilada a 60 gL destilada, testemunha (sem caulim). sobrevivência dos estágios imaturos de P. solenopsis e, na fase adulta, os períodos de pré- ou em água Foram determinados o tempo de duração e a oviposição, oviposição, pós-oviposição, longevidade, fecundidade, número de ovos/dia, número de ovos/fêmea/dia. Foram também estimados os parâmetros das tabelas de fertilidade e de esperança de vida de P. solenopsis para se determinar o potencial de crescimento populacional dessa cochonilha em ambos os tratamentos. Os resultados obtidos nesta pesquisa demonstram que a sobrevivência dos estágios imaturos de P. solenopsis em discos de folhas de algodoeiro não foi prejudicada pelo caulim. No entanto, observou-se menor duração do desenvolvimento dos segundo e terceiro instares e do período de ovo à adultos de fêmeas de P. solenopsis no tratamento com suspensão de caulim e um maior período de oviposição, fecundidade e número de ovos por fêmea nesse mesmo tratamento. Além disso, o menor tempo necessário para a população de P. solenopsis duplicar em número de indivíduos (TD) associado aos maiores valores das taxas bruta (TBR) e líquida de reprodução (Ro), razões intrínseca (rm) e finita de crescimento (λ), sobrevivência, fertilidade específica (mx), valor reprodutivo (VRx) e esperança de vida (ex) no tratamento com suspensão de caulim, indicam que as pulverizações desse produto nas lavouras de algodoeiro infestadas pela cochonilha devem ser evitadas porque favorecem seu crescimento populacional.

Phenacoccus peruvianus (Hemiptera: Pseudococcidae) is an invasive mealybug of Neotropical origin, first reported in the Mediterranean Basin in Almeria (Spain) in 1999. In the following years the mealybug spread into other Mediterranean regions and has also been recorded in Portugal and France, as well as in Sicily, Corsica and the Balearic Islands. Phenacoccus peruvianus is a polyphagous species and damages economically important ornamental plants. Since this was a relatively unknown species, during the first years of invasion, the mealybug was managed by the application of chemical treatments with wide-spectrum pesticides. However, the latest European directive on pesticide use reduces or even forbids pesticide applications in a wide range of urban green areas, giving significant priority to biological control (European Parliament and Council 2009). This thesis sets the basis for introducing biological control into a P. peruvianus management program in urban landscapes, focusing on its characterization, sampling, biology and control. In order to facilitate the identification of this and other mealybug species, we characterised 33 mealybug populations infesting crops and ornamental plants in Eastern Spain, using a combination of molecular and morphological techniques. This characterisation led to the identification of ten mealybug species and made routine identification possible through DNA sequencing or the use of derived species-specific molecular tools. The sequences obtained also add to the phylogenetic knowledge of the Pseudococcidae family and provide insight into the invasion history of some species. Phenacoccus peruvianus populations were high in bougainvillea plants during spring and summer, declining to almost undetectable levels in autumn and winter. The mealybug was mainly found in bracts and there were no significant migrations between plant strata. Phenacoccus peruvianus showed a high aggregated distribution on bracts, leaves and twigs. We recommend a binomial sampling of 200 leaves and an action threshold of 55% infested leaves for IPM purposes in urban landscapes. Its most abundant natural enemies were found to be the primary parasitoids Acerophagus n. sp. near coccois and Leptomastix epona Walker (Hymenoptera: Encyrtidae). We also identified several predator species from the Anthocoridae, Coccinellidae, Chamaemyiidae, and Chrysopidae families. Phenacoccus peruvianus populations were lower during the second and third year of the survey, coinciding with an increase in the parasitoid Acerophagus sp. populations, which displaced the native L. epona. Differential female offspring and resource preemption are discussed as the main reasons for this displacement. To obtain further information on the biology of the new parasitoid Acerophagus sp. we determined some traits of its reproductive and feeding strategies. Acerophagus sp. egg load reached its maximum when it was 5 days old with almost 30 mature eggs. Phenacoccus peruvianus second and third nymphal instars and adults were suitable for parasitism and efficient encapsulation was low (10.76 ± 0.31 %). The parasitoid always preferred older instars when different host instars were available. Acerophagus sp. developed as a solitary parasitoid in the second instar and as a gregarious parasitoid in older instars (2¿4 parasitoids per host). Moreover, it reproduced parthenogenetically and all the emerged offspring were females. Immature development lasted between 20 and 22 days at 25°C and 65% HR. Under these conditions, adults lived for longer than 20 days when fed on honey, but fewer than 3 days when fed on naturally occurring sugar sources (host honeydew and Bougainvillea glabra flowers).
Beltrà Ivars, A. (2014). Biology and management of the invasive mealybug Phenacoccus peruvianus (Hemiptera: Pseudococcidae) in urban landscapes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37233
TESIS

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia
The main objective of Centro de Investigação das Ferrugens do Cafeeiro, Instituto de Investigação Científica Tropical (CIFC/IICT) is to contribute for the development of coffee varieties resistant to coffee leaf rust, Hemileia vastatrix. Mealybugs are a major phytossanitary problem of coffee varieties maintained by CIFC/IICT, due to their interference with the production of young coffee leafs necessary for the inoculation of fungi. The aims of the present work were: a) to identify the mealybug species associated with commercial varieties of coffee, such as Catimor and Sarchimor, in the greenhouses of CIFC/IICT; b) to study the dynamics of infestation of Planococcus citri in the varieties Catimor and Sarchimor, under greenhouse conditions; c) to compare the colonization rate and development of P. citri in two coffee genotypes, one resistant to coffee leaf rust (Catimor CIFC 45) and one susceptible (Caturra vermelho CIFC 19/1). Two species of mealybugs were identified, Phenacoccus madeirensis and P. citri. The variety Catimor was the most susceptible to P. citri. No significant differences were observed in the development time of P, citri among the studied varieties. Nevertheless, the rate of colonization by mealybugs was higher in Caturra CIFC 19/1

L’enroulement de la vigne cause des pertes de rendement et de la qualité des vins au niveau mondial. Il est causé par quatre espèces de Grapevine leafroll-associated virus(GLRaVs) ; GLRaV-1, -2, -3, -4-like. Si le GLRaV-2 (genre Closterovirus) ne possède pas de vecteur connu, les trois autres espèces (genre Ampelovirus) sont transmises par cochenilles(Coccoidea) qui contribuent à leur dispersion dans et entre les vignobles. Les vignobles de la France septentrionale (Alsace, Bourgogne, Champagne) sont les plus impactés par l’enroulement viral. Ce travail a porté sur le rôle vecteur de Phenacoccus aceris, espèce connue pour son efficacité de transmission et de dispersion des ampélovirus, ainsi que de vitivirus souvent associés. Les interactions cellulaires et moléculaires entre virus et cochenille restent peu connues. Une approche pluridisciplinaire combinant entomologie,virologie, biologie cellulaire et moléculaire a été développée pour étudier la biologie de la vection du GLRaV-1 et du Grapevine virus A (GVA) par P. aceris. Des expériences de transmission ont montré que ces virus sont transmis selon le mode semi-persistant non circulant. L’étude préliminaire du comportement alimentaire de P. aceris sur vigne par électropénétrographie a révélé une activité similaire à celle d'autres espèces de cochenilles déjà décrites et suggère un effet de l’infection sur le comportement alimentaire. L’anatomie des pièces buccales de P. aceris, organes directement impliqués dans la transmission et la rétention de virus non-circulants a été décrite et une méthode basée sur l’acquisition de virus purifié sur membrane a été développée pour rechercher les sites de rétention virale dans le vecteur
Grapevine leafroll disease affects grape yield and wine quality worldwide. It is caused by four species of Grapevine leafroll-associated virus (GLRaVs) (GLRaV-1, -2, -3, -4-like).While GLRaV-2 (genus Closterovirus) has no known vector, the other three (genus Ampelovirus) are transmitted by mealybugs (Coccoidea) and thus prone to be dispersed within and between vineyards. In north-eastern France (Alsace, Bourgogne et Champagne),vineyards are more impacted by Grapevine leafroll disease. This thesis focusses on the vector role of the species Phenacoccus aceris, known for its efficiency in transmission and dissemination of ampeloviruses, as well as often associated vitiviruses. Molecular and cellular interactions between viruses and mealybugs remain poorly known. A multidisciplinary approach, combining entomology, virology, molecular and cellular biology, was developed to analyse the vector biology of GLRaV-1 and Grapevine virus A (GVA) by P. aceris.Transmission experiments showed that GLRaV-1 and GVA transmission follows the semipersistent non-circulative mode. A preliminary study of P. aceris feeding behavior on grape using electropenetrography revealed an activity similar to that of other mealybug species already described and suggested a potential effect of infection on Ph. aceris feeding behavior. The anatomy of mouth parts, directely implied in transmission and retention of non circulative viruses was described and a method for membrane acquisition of purified virus was developed to search for virus retention sites within the vector

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This study aimed to evaluate the action of entomopathogenic fungi and plant protection products used in alternative agroecological on nymphs of P. manihoti in cassava. The four upper leaves of cassava plants infested with nymphs of the mealybug P. manihoti application of treatments received in the lower surface of leaves on the nymphs, using a spray nozzle attached to an air compressor. After application, the plants were kept in semi-conditioned room (temperature 25 ± 5 º C and a photoperiod of 12h) and other insects on the leaves with the aid of prepared leaf cages per screen anti-aphids. The pesticides were evaluated by the insect mortality at 3, 5, 7 and 9 days after application. The mortality caused by strains of entomopathogenic fungi and commercial insecticides on nymphs was assessed daily for 10 days. For confirmation of death by the pathogen, the bodies were immersed in 70% alcohol and then in distilled water, transferred to Petri dishes and maintained at temperature (26 ± 1 ° C and a photoperiod of 14 hours). It was observed that all pesticides tested on nymphs proved efficient when the final assessment, however, differ in the mortality rate, and the products Pironim®, Lime sulfur®, Compostonat® and Plant Clean® presented the efficiency causing at least 50% mortality of nymphs of P. manihoti. Among isolates tested, only three were pathogenic to P. manihoti causing the corrected mortality varied from 15,2 to 28.5%, following 10 days of application. The other isolates tested showed low activity or were not pathogenic to Scale. The commercial biopesticides based on fungi were pathogenic to the nymphs of P. manihoti, causing mortality of 10 to 45.8%, and the best result was obtained with the product based on B. bassiana (Bovenat®) which provided 45.8% mortality confirmed
Este estudo teve como objetivo avaliar a ação de fungos entomopatogênicos e de produtos fitossanitários alternativos utilizados no sistema agroecológico de produção sobre ninfas de P. manihoti na cultura da mandioca. As quatro folhas apicais de plantas de mandioca infestadas com ninfas da cochonilha P. manihoti receberam aplicação dos tratamentos na face abaxial, sobre as ninfas, utilizando-se um micro pulverizador acoplado a um compressor de ar. Após a aplicação, as plantas foram mantidas em sala semi-climatizada (temperatura de 25 ± 5ºC e fotoperíodo de 12h) e os insetos mantidos nas folhas com auxílio de gaiolas. Os produtos fitossanitários foram avaliados através da mortalidade dos insetos aos 3, 5, 7 e 9 dias após a aplicação. A mortalidade causada pelos isolados de fungos entomopatogênicos e bioinseticidas comerciais sobre ninfas foi avaliada diariamente pelo período de 10 dias. Para confirmação da mortalidade pelo patógeno, os cadáveres foram imersos em solução de álcool 70% e posteriormente em água destilada, transferidos para placas de Petri e mantidas em câmara climatizada (26±1°C e fotoperíodo de 14 horas). Verificou-se que todos os produtos fitossanitários testados sobre as ninfas mostraram efeito ao final da última avaliação, no entanto, diferiram quanto a porcentagem de mortalidade, sendo que os produtos Pironim®, Calda fertilizante foliar®, Compostonat® e Planta Clean® apresentaram a maior mortalidade de ninfas de P. manihoti causando no mínimo 50%. Dentre os isolados testados, apenas três foram patogênicos à P. manihoti causando mortalidade corrigida que variou de 15,2 a 28,5%. Os demais isolados testados apresentaram baixa atividade ou não foram patogênicos à cochonilha. Os bioinseticidas comerciais à base de fungos foram patogênicos às ninfas de P. manihoti, causando mortalidade de 10 a 45,8%, sendo que o melhor resultado foi obtido com o produto à base de B. bassiana (Bovenat®) que proporcionou 45,8% de mortalidade confirmada

Un criblage pratique au champ sur 25 varietes de manioc a permis d'identifier des cultivars presentant differents degres d'antibiose et d'antixenose. L'evaluation au laboratoire de la composante antibiotique sur 7 varietes de manioc, du faux-caoutchouc et de 2 plantes de substitution, talinum (talinum triangularae jacq) et poinsettia (euphorbia pulcherrima willd) montre que l'expression du potentiel biotique du ravageur est influencee par la plante-hote. L'infestation par la cochenille modifie peu la croissance de la plante traduisant la tolerance du manioc a p. Manihoti. Les modifications des teneurs en substances primaires (acides amines et sucres) et secondaires (composes cyanes et phenoliques) suite a l'infestation varient avec la plante-hote. La resistance de type antibiose qui n'a pas pu etre reliee aux teneurs en substances primaires semble etre correlee aux teneurs en substances secondaires. Les composes cyanes auraient un role phagostimulant, alors que les flavonoides glycosyles totaux et la rutine un role phagodissuadant. Enfin, l'etude de quelques techniques agronomiques montre que les augmentations de teneurs de l'acide cyanhydrique de la rutine et des flavonoides glycosyles totaux de l'extrait de feuilles de manioc (zanaga) apres infestation sont plus importantes avec le paillage, la fumure organique et l'amendement calcique qu'avec du npk ou du kcl en toute saison. Cependant, la plus forte augmentation intervient en saison seche

O trabalho teve como objetivos gerais avaliar o efeito da poda, da adubação nitrogenada e os compostos químicos secundários presentes em genótipos de mandioca industrial no manejo da cochonilha Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). O primeiro experimento teve como objetivo específico avaliar o efeito de diferentes formas de poda e de manejos da parte aérea da mandioca sobre a incidência da cochonilha P. manihoti no segundo ciclo da cultura e na produção e renda de raízes tuberosas. O experimento foi conduzido nos municípios de Nova Londrina e Diamante do Norte/PR, sob o delineamento de blocos ao acaso com quatro repetições e sete tratamentos: poda total, rente ao solo sem permanência de material vegetal na parcela; poda total, rente ao solo com permanência do material vegetal na parcela; poda convencional (15 cm do solo) sem permanência do material vegetal na parcela; poda convencional com permanência do material vegetal na parcela; poda convencional, com a parte mediana da planta na parcela, com retirada do terço superior da planta; poda convencional, com a retirada da parte mediada da parcela e permanência do terço superior da planta; testemunha - sem poda. Foi realizado o acompanhamento da incidência da praga, a cada 15 dias por 2 meses, atribuídindo-se uma nota de dano. As avaliações foram realizadas em quatro pontos ao acaso em zigue e zague em 16 plantas. No momento da colheita foram avaliados a produtividade e a renda de raízes tuberosas. O segundo experimento teve como objetivo avaliar o efeito de doses de adubação nitrogenada sobre a produção de compostos secundários ao longo do tempo. O experimento foi realizado em casa de vegetação semiclimatizada da Embrapa Soja em Londrina/PR, com cultivo das plantas em vasos, em esquema fatorial 2x4x3, com 5 repetições. Foram utilizados dois genótipos de mandioca (Baianinha e Caiuá) e quatro doses de nitrogênio (0, 30, 60 e 90 kg ha-1), com avaliações aos 15, 30 e 45 dias após a adubação. A adubação nitrogenada foi realizada com ureia, 60 dias após o plantio das manivas. Nas folhas apicais foram avaliados os teores de rutina e de ácidos caféico, p-cumárico e ferúlico em cromatógrafo líquido de alto desempenho (HPLC). O terceiro experimento teve como objetivo identificar e quantificar compostos secundários, bem como as alterações nos teores destes, em folhas apicais e basais, de cultivares de mandioca ao longo do tempo após a infestação com a cochonilha da parte aérea P. manihoti. Para cada, foram realizados dois ensaios, ambos sob delineamento inteiramente casualizado com cinco repetições. O primeiro ensaio deste foi esquema fatorial 3x2x2, sendo três cultivares de mandioca: Baianinha, Santa Helena e IAC-12, suscetível, moderadamente resistente e resistente a P. manihoti, respectivamente, duas partes da planta (apical e basal) com e sem a presença de P. manihoti (infestado e não infestado). O segundo ensaio deste, foi realizado em esquema fatorial 3x2x5, sendo três genótipos de mandioca: Baianinha, Santa Helena e IAC-12, com e sem a presença de P. manihoti (nfestado e não infestado com o inseto), cinco coletas de folhas ao longo do tempo (24, 48, 72, 96 e 120 h) após infestação do inseto. As plantas foram cultivadas em vasos com capacidade para cinco litros de solo em casa de vegetação. Para a infestação, folhas contendo cinco ninfas de primeiro para segundo instar, oriundas de criação massal, foram acomodadas no ápice das plantas por 24 h. As folhas apicais e basais de cada planta foram coletadas em cada tempo e congeladas em N líquido. Os extratos foliares obtidos foram levadas ao cromatógrafo líquido de alto desempenho (HPLC), onde foram identificados e quantificados os teores de ácido caféico, p-cumárico, ferúlico, gálico e rutina. Os dados foram submetidos à análise de homogeneidade e normalidade, análise de variância e comparação de médias (Tukey 5%), e dados de doses, de tempo de infestação e N ao teste de regressão. A cochonilha da parte aérea da mandioca P. manihoti tem maior incidência e causa maior dano quando não é realizada a poda da cultivar Caiuá. Os danos causados pelas cochonilhas e os tipos de poda e manejo da parte aérea da planta não afetam a produtividade e renda de raízes tuberosas na variedade de mandioca Caiuá. A cultivar Caiuá apresenta maior teor de ácido ferúlico. O teor de ácido caféico diminui ao longo do tempo após a aplicação de N. O teor de rutina nas cultivares de mandioca Baianinha e Caiuá são aumentam com o acréscimo das doses de nitrogênio. As cultivares de mandioca Baianinha, Santa Helena e IAC 12 expressam ácido caféico, ácido p-cumárico, ácido ferúlico e ácido gálico em folhas apicais e basais. Folhas basais apresentam maior concentração de ácido caféico que folhas apicais de mandioca. Folhas basais apresentam maior teor de ácido ferúlico nas cultivares Baianinha e Santa Helena. A presença de P. manihoti aumenta a produção de ácido ferúlico até as 65 h e p-cumárico até as 75 h, na cultivar Baianinha e reduz linearmente o teor de ácido p-cumárico na cultivar IAC 12. Plantas de mandioca apresentaram maiores teores de rutina as 24 h de coleta na região apical, independente da presença de P. manihoti. A presença de P. manihoti aumentou a produção de rutina em folhas apicais da cultivar de mandioca Baianinha as 24 h. Os maiores teores de rutina são observados na cultivar Baianinha, e os menores na IAC 12. A cultivar Santa Helena infestada com P. manihoti apresenta acréscimo linear na concentração de rutina ao longo do tempo e as cultivares Baianinha e Santa Helena não infestadas apresentaram acréscimo na produção de rutina até 99 e 114 h, respectivamente.
The objective of this work was to evaluate the effect of pruning, nitrogen fertilization and secondary chemical compounds present in industrial cassava genotypes in the management of Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). The first experiment had as objective to evaluate the effect of different forms of pruning and manioc management on the incidence of P. manihoti cochineal in the second crop cycle and in the production and yield of tuberous roots. The experiment was conducted in the municipalities of Nova Londrina and Diamante do Norte/PR, under a randomized block design with four replications and seven treatments: total pruning, close to the soil without permanence of plant material in the plot; Total pruning, close to the soil with permanence of the vegetal material in the plot; Conventional pruning (15 cm of the soil) without permanence of the vegetal material in the plot; Conventional pruning with permanence of the vegetal material in the plot; Conventional pruning, with the middle part of the plant in the plot, with removal of the upper third of the plant; Conventional pruning, with the removal of the mediated part of the plot and permanence of the upper third of the plant; Witness - without pruning. The incidence of the pest was monitored every 15 days for 2 months, assigning a damage note. The evaluations were carried out in four random points in zigzag and zag at 16 plants. At the time of harvest, productivity and yield of tuberous roots were evaluated. The second experiment had as objective to evaluate the effect of doses of nitrogen fertilization on the production of secondary compounds over time. The experiment was carried out in a greenhouse of Embrapa Soja in Londrina/PR, with potted plants cultivation, in a 2x4x3 factorial scheme, with 5 replicates. Two cassava genotypes (Baianinha and Caiuá) and four nitrogen doses (0, 30, 60 and 90 kg ha-1) were used, with evaluations at 15, 30 and 45 days after fertilization. Nitrogen fertilization was carried out with urea, 60 days after the planting of the roots. In the apical leaves, the levels of rutin and of coffee, p-coumaric and ferulic acids were evaluated in a high performance liquid chromatograph (HPLC). The third experiment had as objective to identify and quantify secondary compounds, as well as the changes in their contents, in apical and basal leaves, of cassava cultivars over time after infestation with the P. manihoti shoot. For each, two trials were performed, both under a completely randomized design with five replicates. The first experiment was a 3x2x2 factorial design, with three manioc cultivars: Baianinha, Santa Helena and IAC-12, susceptible, moderately resistant and resistant to P. manihoti, respectively, two parts of the plant (apical and basal) with and without Presence of P. manihoti (infested and non-infested). The second trial was carried out in a 3x2x5 factorial scheme, with three cassava genotypes: Baianinha, Santa Helena and IAC-12, with and without P. manihoti (nfested and not infested with the insect), five leaves (24, 48, 72, 96 and 120 h) after infestation of the insect. The plants were grown in pots with a capacity of five liters of soil in a greenhouse. For infestation, leaves containing five nymphs from first to second instar, originating from mass rearing, were accommodated at the apex of the plants for 24 h. The apical and basal leaves of each plant were collected at each time and frozen in liquid N. The leaf extracts obtained were submitted to high performance liquid chromatography (HPLC), where the levels of coffee, p-coumaric acid, ferulic acid, gallic acid and rutin were identified and quantified. The data were submitted to analysis of homogeneity and normality, analysis of variance and comparison of means (Tukey 5%), and data of doses, time of infestation and N to the regression test. The P. manihoti cassava mealybug have a higher incidence and cause greater damage when pruning of the Caiuá cultivar is not performed. The damages caused by the mealybug and the types of pruning and management of the aerial part of the plant do not affect the productivity and income of tuberous roots in the variety of cassava Caiuá. The cultivar Caiuá presents higher content of ferulic acid. The content of caffeic acid decreases over time after the application of N. The rutin content in the cassava cultivars Baianinha and Caiuá are increased with the addition of nitrogen doses. Baianinha, Santa Helena and IAC 12 cassava cultivars express caffeic acid, p-coumaric acid, ferulic acid and gallic acid in apical and basal leaves. Basal leaves have a higher concentration of caffeic acid than mandioca apical leaves. Basal leaves present higher ferulic acid content in Baianinha and Santa Helena cultivars. The presence of P. manihoti increases the production of ferulic acid up to 65 h and p-coumaric up to 75 h in the Baianinha cultivar and linearly reduces the content of p-coumaric acid in cultivar IAC 12. Cassava plants presented higher levels of rutin The 24 h of collection in the apical region, independent of the presence of P. manihoti. The presence of P. manihoti increased routine yield on apical leaves of the Baianinha cassava cultivar at 24 h. The highest levels of rutin are observed in the Baianinha cultivar, and the lowest in the IAC 12. The cultivar Santa Helena infested with P. manihoti presents a linear increase in the rutin concentration over time and the non-infested cultivars Baianinha and Santa Helena presented an increase in Production of rutin up to 99 and 114 h, respectively.

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Phenacoccus manihoti is an important pest of cassava in the region Center-South of Brazil, causing damage mainly cultivated during the second cycle. The use of resistant genotypes and biological control agents are the most promising techniques in the control of this pest. The objective of this research was to evaluate the resistance of genotypes of cultivated cassava and obtained in breeding programs to mealybug P. manihoti and its influence on the parasitoid A. lopezi. The biological aspects of P. manihoti and A. lopezi were evaluated in different cassava genotypes and with these data tables of life and fertility of both were prepared. To verify the occurrence of resistance induction of infestation of P. manihoti genotypes were evaluated on the activity of peroxidase, polyphenol oxidase , amino acids and reducing sugars . In the absence of mealybug was also rated the content (CN-) of different genotypes. Although P. manihoti and A. lopezi showed differences in their biological aspects when reared on different genotypes of cassava has not been possible to verify the action of resistance of genotypes evaluated on these parameters. There was a positive correlation between fecundity of A. lopezi and its host P. manihoti in different genotypes, indicating that genotypes susceptible to mealybug positively influence the reproduction of its parasitoid . We observed an increased incidence of plant defenses due to inoculation with P. manihoti associated with increases in the activity of peroxidase, polyphenol oxidase, amino acids and reducing sugars in most genotypes. However, only the activities of peroxidase and polyphenol oxidase appear to be involved in the resistance of the genotypes evaluated
Phenacoccus manihoti é uma importante praga de mandioca na região Centro-Sul do Brasil, causando danos principalmente nos cultivos de segundo ciclo. O uso de genótipos resistentes e do controle biológico são as técnicas mais promissoras no controle dessa praga. O objetivo desta pesquisa foi avaliar a resistência de genótipos de mandioca cultivadas e obtidas em programas de melhoramento genético à cochonilha P. manihoti e sua influência sobre o parasitoide A. lopezi. Os aspectos biológicos de P. manihoti e Anagyrus lopezi foram avaliados em diferentes genótipos de mandioca e com estes dados foram elaboradas as tabelas de vida e fertilidade de ambos. Também foram avaliados a atividade de peroxidase, polifenoloxidase, aminoácidos e açúcares redutores em plantas infestadas e na ausência da cochonilha foi avaliado o teor de (CN-) dos diferentes genótipos. Embora P. manihoti e A. lopezi apresentaram diferenças em seus aspectos biológicos quando criados em diferentes genótipos de mandioca não foi possível verificar ação da resistência dos genótipos avaliados sobre estes parâmetros. Houve correlação positiva entre a fecundidade de A. lopezi e seu hospedeiro P. manihoti nos diferentes genótipos, indicando que genótipos suscetíveis à cochonilha influenciam positivamente a reprodução de seu parasitoide. Observou-se a ocorrência de aumento das defesas das plantas em função da inoculação com P. manihoti associada a aumentos na atividade de peroxidase, polifenoloxidase, aminoácidos e açúcares redutores na maioria dos genótipos. Porém, apenas as atividades de peroxidase e polifenoloxidase parecem estar envolvidas na resistência dos genótipos avaliados

Hyperaspis raynevali et Exochomus flaviventris sont deux coccinelles prédatrices de la cochenille du manioc Phenacoccus manihoti Matile-Ferrero (Hom. Pseudoccocinae). Différents aspects concernant l'activité prédatrice et la bioécologie de ces coccinelles sont abordées dans ce mémoire. Une étude de la prédation des larves d'H. Raynevali et d'E. Flaviventris sur les colonies de la cochenille du manioc a été conduite a l'échelle de parcelles paysannes. Un premier lâcher de larves de prédateurs au début de la gradation influence significativement l'évolution des effectifs moyens de P. Manihoti. Un second lâcher est réalisé deux et trois semaines plus tard sur les mêmes plants en péridode de forte multiplication des colonies ; son influence sur l'évolution des colonies de cochenilles n'a pu être décelée car l'apport de coccinelles intervient simultanément avec d'autres facteurs de régulation responsables de la réduction des effectifs du ravageur. D'après cette étude, la prédation des larves de coccinelles dépend essentiellement de la densité et de la structure d'âge des colonies du ravageur. Cependant la difficulté de contrôler simultanément les facteurs d'ambiance et ceux propres à la dynamique des colonies de cochenilles, n'a pas permis de comparer les deux espèces de coccinelles entre elles. Une expérimentation a donc été conduite en condition de laboratoire afin de préciser l'importance des paramètres précédemmment cités, ainsi que celle du rapport proie/prédateur, sur la prédation des larves d'E. Flaviventris et d'H. Raynevali. La prédation des larves de coccinelles est plus importante sur des colonies de 45 cochenilles / plant que sur celles de 25 cochenilles par plant. L’apport de prédateur permet de limiter significativement la multiplication des colonies de P. Manihoti constituées d'adultes et de larves néonates, et de réduire significativement les effectifs de cochenilles composés de 2ème et 3ème stades larvaires. Pour les deux espèces de coccinelles, les lâchers effectués avec le rapport proie-prédateur de 3 cochenilles pour 1 larve de coccinelle (3/1) ont une influence plus grande sur la réduction des effectifs de cochenilles que ceux réalisés avec un rapport de 7/1. Pour tous les paramètres étudiés, la coccinelle exotique H. Raynevali maintient les densités de P. Manihoti a des niveaux inférieurs à ceux obtenus avec l'espèce indigène E. Flaviventris. Pour les deux espèces étudiées, la prédation intervient dès le lâcher et se prolonge pendant quelques jours, puis, les larves de coccinelles ont tendance à quitter les plants de manioc. Une étude bioécologique des coccinelles est entreprise afin d'essayer de préciser certains facteurs limitants potentiels de l'activité prédatrice, et d'établir leur spécificité trophique. Dans la région de Brazzaville, la présence des fourmis ne semble pas constituer un facteur limitant de l'activité prédatrice des coccinelles E. Flaviventris et H. Raynevali. L'association entre les fourmis et les cochenilles serait liée a la présence de miellat qui constituerait une source de nourriture saisonnière. Un suivi des ennemis naturels d'E. Flaviventris permet de déceler le parasitisme du stade nymphal par deux Hymenoptères Encyrtidae. La polyphagie de ce prédateur est spécifiée par l'inventaire des proies qu'il exploite en conditions naturelles, tout au long de l'année. Des essais d'introduction de la coccinelle neo tropicale H. Raynevali sont effectués. Un seul adulte, issu d'un lâcher en 1989, est retrouvé en 1990. Au Congo, ce prédateur semble capable de se maintenir dans les conditions naturelles mais il ne peut être considéré comme appartenant à l'entomofaune prédatrice de la cochenille du manioc. L'etude bioécologique d'H. Raynevali n'a pu être menée avec autant de précision que celle du prédateur local en raison de sa présence éphémère a la suite des lâchers d'introduction. Ll'utilisation des coccinellles E. Flaviventris et H. Raynevali dans la perspective d'une lutte biologique contre la cochenille du manioc est évoquée en discussion. Des voies de recherches sont également proposées.

E. Flaviventris est une espece coccidiphage capable de se nourrir d'aphides. Polyphage et sedentaire, elle adopte une strategie de reproduction du type r et peut developper dans les conditions optimales d'elevage, 7 a 8 generations par an. Elle presente l'avantage de consommer beaucoup de proies tous stades de developpement confondus. Malgre une capacite d'accroissement assez faible, un cycle de developpement et une maturation sexuelle relativement longs, une fecondite assez moyenne, une constante thermique et un seuil thermique theorique tres eleves, e. Flaviventris presente des qualites antagonistes interessantes. Son utilisation en lutte biologique et son role dans la maitrise des populations de la cochenille farineuse du manioc sont largement justifies par rapport aux autres especes de coccinelles. Elle presente, en effet, de meilleures chances sur le plan de l'occupation spatiale du terrain grace a sa polyphagie qui lui offre ainsi des garanties supplementaires de survie dans les ecosystemes les plus divers, meme en l'absence periodique de p. Manihoti. Sa grande voracite devrait lui permettre de jouer un role de regulation des les premieres pullulations de la cochenille du manioc. Son aptitude a pouvoir se multiplier massivement sur une nourriture de substitution (les ufs d'e. Kuehniella) contribue a augmenter ses potentialites biologiques et a faciliter le renforcement periodique de ses populations naturelles.

Les virus de l'enroulement de la vigne (Grapevine leafroll-associated virus, GLRaV) sont répandus mondialement et transmis à la vigne uniquement par cochenilles (Coccoidea). En France, l'enroulement viral affecte particulièrement les vignobles des régions septentrionales.L'approche biologique de la vection a montré la capacité de Phenacoccus aceris à transmettre à la vigne les GLRaV-1, -3, -4, -5, -6, -9 et ceux du bois strié Grapevine virus A et B. Cette étude est la première démonstration de la transmission du GLRaV-6 et confirme l'absence de spécificité des cochenilles dans la transmission des Ampelovirus. Les larves néonates de P. aceris et de Neopulvinaria innumerabilis représentent un stade de développement efficace pour la transmission de ces virus. En conséquence, leurs capacités vectrices, associées à leur fort potentiel de dissémination anémophile, impliquent un risque important de dispersion naturelle de ces virus dans un vignoble infesté. Les relevés sur quatre parcelles distinctes montrent que Parthenolecanium corni, Pulvinaria vitis, Heliococcus bohemicus et P. aceris sont communes, chaque vignoble différant par la diversité spécifique, le taux de ceps infestés et l'abondance des cochenilles. L'étude épidémiologique prouve le rôle des cochenilles dans la dispersion de l'enroulement viral dans les vignobles septentrionaux. A Bonzon, la responsabilité de P. aceris dans la diffusion rapide du GLRaV-1 est mise en évidence. Cette découverte représente la première preuve en Europe d'une dispersion naturelle du GLRaV-1. A Marsannayla-Côte, l'incidence du GLRaV-1 reste faible, la colonie de P. aceris ne semblant avoir qu'un rôle très limité dans la diffusion de la maladie. L'épidémiologie moléculaire à Bonzon révèle une diversité génétique importante du GLRaV-1 à l'échelle parcellaire et fournit pour la première fois des données sur le polymorphisme génétique d'une population de GLRaV-1 ayant été dispersée par des cochenilles.

D'origine neotropicale, la cochenille du manioc phenacoccus manihoti a ete introduite accidentellement en afrique intertropicale vers les annees 70. Des predateurs locaux se sont adaptes a ce nouveau phytophage et on les observe presque dans toutes les parcelles de manioc. Malheureusement on ne sait rien de leur fonction de predation avant l'introduction de p. Manihoti. Comme on ne les avait pas etudies avant, on peut faire l'hypothese de predateurs se developpant habituellement aux depens des proies ayant des niveaux d'abondance et des variations d'amplitude numerique relativement faibles. Dans cette hypothese, ces entomophages devraient presenter des traits biologiques communs a savoir: 1) une fecondite faible; 2) une periode de ponte longue; 3) un pouvoir d'accroissement de leur population relativement modeste. C'est effectivement ce qu'on a constate chez exochomus flaviventris et hyperaspis senegalensis hottentotta (col. : coccinellidae). Diomus hennesseyi (col. : coccinellidae) est une espece recoltee en amerique du sud pour etre introduite en afrique. Notre etude montre que ses traits biologiques (duree du developpement, fecondite et potentiel d'accroissement de population) sont differents et plus interessants que ceux releves chez les predateurs locaux

L'influence de la plante-hote de phenacoccus manihoti (hem. , pseudococcidae) sur le comportement de recherche de l'hote et l'expression du potentiel biotique du parasitoide epidinocarsis lopezi (hym. , encyrtidae) a ete etudiee en conditions experimentales de laboratoire. L'experimentation a porte sur quatre plantes caracterisees par differents niveaux de resistance antibiotique et antixenotique vis a vis de la cochenille: 2 varietes de manioc manihot esculenta (incoza et zanaga) ; le faux-caoutchouc (hybride de m. Esculenta et m. Glaziovii) et le talinum (talinum triangularae). L'influence de la plante-hote sur le comportement locomoteur de recherche de l'hote par e. Lopezi a ete etudiee a l'aide d'un olfactometre tubulaire a flux d'air continu et d'un olfactometre en y. En olfactometre tubulaire, les odeurs des plantes saines et infestees ainsi que celles des cochenilles elevees sur chacune des plantes stimulent l'activite locomotrice des femelles. Par contre, seules les plantes infestees et les cochenilles elevees sur manioc sont attractives. En olfactometre en y, les femelles d'e. Lopezi preferent l'odeur du manioc m. Esculenta sain a celle de t. Triangularae sain. Au sein de m. Esculenta, l'hymenoptere ne fait pas de discrimination entre les deux varietes incoza et zanaga. Par contre, il prefere cette derniere a l'hybride faux-caoutchouc. A l'etat infeste, les femelles preferent incoza et zanaga aux deux autres plantes. Par ailleurs, e. Lopezi ne fait pas de discrimination entre les cochenilles elevees sur les plantes du genre manihot (. . . )

The incidental introduction of alien phytophagous insects and mites has become quite a common event in the world owing to intensive commercial exchanges of plants and goods and ever-increasing tourist traffic. There is evidence that this phenomenon is increasing, in spite of the control measures of the EU phytosanitary system in order to minimize unintentional introductions. The introduction of an alien species in a new ecosystem and the interaction between an alien species and the autochthonous species usually has many disadvantages. The alien species can dominate the invaded ecosystems and eventually become an invasive species due also to the absence or paucity of natural enemies. These invasions can affect the native species that become less common or threatened with extinction. Apart from the environmental impacts alien species are known for their economic and health impacts. In this study were investigated mostly 3 recently introduced alien species in Italy, namely Tuberocephalus (Trichosiphoniella) tianmushanensis Zang (Hemiptera Aphididae), Cydalima perspectalis (=Glyphodes) (Walker, 1859) (Lepidoptera Crambideae), the box caterpillar and Phenacoccus defectus Ferris (Rhynchota Pseudococcidae). The first chapter is a background of invasive ecology and presents with graphs the high number of alien species introduced in Europe the last years.. The second chapter is dealing with Tuberocephalus (Trichosiphoniella) tianmushanensis Zang, an Asiatic heteroecious species so far not recorded in Italy. This species was collected in the University Botanical Garden of Padova in spring 2012. On May 30, 2012 reddish-pink galls, with aphids inside, were observed on the leaves of two Prunus subhirtella cv. pendula trees (Rosaceae) (Weeping Higan Cherry), about 40 years old. Once mounted on slides the aphids were identified as Tuberocephalus (Trichosiphoniella) tianmushanensis Zang. The purposes of this study were to collect data on species distribution over the territory, by monitoring ornamental cherry trees in the Veneto region, to observe the phenology and biology of the Asiatic aphid, to study the life-cycle in screen houses and outdoors, to verify if its secondary host plant was an Artemisia sp., as reported in bibliography. Another aspect of the work was to provide an overview of the species belonging to the genus Tuberocephalus so far described, by consulting the available literature. It was made an effort to gather all the currently available information for each species, its distribution and information on their biology mainly regarding the first and secondary host plants. Results showed that Tuberocephalus (T.) tianmushanensis, is now considered acclimatized in our environment. The aphid is closely related to the presence of its primary host Prunus subhirtella v. pendula with pink flowers. The aphid can carry on two generations on Prunus and can induce two types of leaf galls. The gall A is induced by the fundatrix, while the gall B is induced by the fundatrigeniae. The trial of colonization on Artemisia vulgaris, failed for the second successive year so possibly Artemisia vulgaris is not the secondary host plant of the aphid, as reported in literature. The third chapter concers Cydalima perspectalis (Lepidoptera, Crambiidae) (Walker, 1859), an asiatic pest of Buxus. It was reported for the first time in Europe in Germany in 2007. In Italy it was detected in 2011, in Lombardy, Como province. In a very short time it invaded the other northern regions and was recorded in Veneto in 2012. The larvae feed on leaves and shoots of the box trees and the infestations lead to defoliation of the plants. The objective of this study was to investigate the phenology of C. perspectalis. More precisely we examined the biological cycle of life, the number of molts and the overwintering stage. In addition host plants were monitored by regular samplings, from late winter to late fall to collect data on species distribution over the territory. The life-cycle was studied in screen houses and in the field, to investigate the role of potential predators and parasitoids. Additionally experiments were conducted with pheromones traps with the purpose of checking, monitoring and collecting data on species distribution over the territory, finding any possible differences based on climate, checking the potential differences between types of traps. According to the results of 2014 and 2015 in the Veneto Region C. perspectalis develops three generations / year. In 2014 the overwintering larvae started their activity early in February until mid-April while in 2015 one month later until end of April probably due to different climate conditions between these years. C. perspectalis overwinters in a silk cocoon in-between the leaves as a larva of 2nd instar and the number of larval instar is 5. The number of captures from the sex pheromones traps was low. No differences were observed between the two types of pheromones. C. perspectalis has spread quickly in our environment proving that it has acclimatized. So far, it seems there has been no adaptation by indigenous natural enemies (parasitoids) to C. persectalis. The next chapter is focued on the difficulty to separate the Phenacoccus solani Ferris and P. defectus Ferris (Hemiptera: Pseudococcidae). They are morphologically similar and the microscopic morphological characters of the adult female alone are not enough. In order to resolve their identity, a canonical variates morphological analysis of 199 specimens from different geographical origins and host plants and a molecular analysis of the CO1 and 28S genes were performed. The morphological analysis supported synonymy of the two species, as although the type specimens of the "species" are widely separated from each other in the canonical variates plot, they are all part of a continuous range of variation. The molecular analysis showed that P. solani and P. defectus are grouped in the same clade. On the basis of the morphological and molecular analyses, P. defectus is synonymized under the senior name P. solani, syn. n. Finally a zoogeographic analysis of the Greek scale insects fauna (Hemiptera, Coccoidea) was carried out with the aim to highlight how many alien scale insects species are so far present in the Greek territory. According to the last data, the scale insect fauna of whole Greek territory comprehends 207 species; a total of 187 species are recorded in mainland Greece and minor islands, whereas only 87 scale species are known so far in the island of Crete. The most numerous families are the Diaspididae, with 86 species in total, followed by Coccidae, with 35 species and by Pseudococcidae, with 34 species. The results of a first zoogeographical analysis of scale insect fauna of mainland Greece and the island of Crete is also presented. Five scale species, respectively four in mainland Greece and one in Crete, are considered as endemic. This analysis demonstrated that alien scale insects, introduced and acclimatized a long time ago or recent invaders, make up 30% of the Greek scale insects fauna.
Tra le specie di Phenacoccus neartiche, P. defectus Ferris, P. solani Ferris è P. solenopsis Tinsley condividono l’insolito carattere morfologico dell’assenza di pori pentaoculari è sono morfologicamente simili da rendere difficile l’ identificazione. Il problema della loro identificazione è stato evidenziato da diversi autori (McKenzie, 1967; Williams & Granara de Willink, 1992; Culik & Gullan, 2005; Pellizzari & Porcelli, 2013), benché sia generalmente riconosciuto che P. solenopsis possieda un maggior numero di pori multiloculari e un circulus di maggiori dimensioni rispetto alle altre due specie; inoltre quest’ultima è una specie bisessuale mentre le altre due si riproducono per partenogenesi. Le tre specie di cocciniglie condividono diverse piante ospite. In accordo con Hodgson et al. (2008) ci sono elementi che supportano l’ipotesi che si tratti di varianti di una singola specie. Per definire meglio il loro status tassonomico, abbiamo amplificato mediante PCR e sequenziato il frammento di DNA ‘barcode’ di P. solani, P. solenopsis, e P. defectus.

碩士
國立臺灣大學
昆蟲學研究所
94
Phenacoccus madeirensis Green (Hemiptera: Pseudococcidae) is a newly invaded pest in Taiwan. Now it has been found in Yilan, Taipei, Taichung, Nantou, Changhua, Chiayi, Tainan and Pingtung. P. madeirensis has wide host range, including 57 species belonging to 19 families in Taiwan. Knowledge of the life cycle of P. madeirensis is essential to the success of its management program. The thesis investigated the effects of constant temperature (15, 20, 25, 28, 30, 32 and 35℃), with 70% RH and 12L: 12D photoperiod, on the development, survival, and reproduction of P. madeirensis on three representative host plants, namely tomato (Lycopersicon esculentum, Solanaceae), mung bean (Phaseolus radiatus, Fabaceae), and hairy beggarticks (Bidens pilosa, Asteraceae). P. madeirensis which reared on tomato at 15 and 35℃ and on mung bean and hairy beggarticks at 35℃ could not successfully complete the life cycle. The mealybug had the fastest development of all stages on three host plants at 30℃. The total duration of development of female mealybugs on tomato, mung bean and hairy beggarticks was about 25, 19 and 20 days, respectively. Males took about 3-7 days longer to develop than females. Developmental threshold (α,℃) from egg to adult on three host plants was 15.6, 19.1 and 18.0℃ for males, and 13.8, 16.6 and 17.4℃ for females, respectively. Adult males required a cumulated effective temperature (K, day-℃) of 399, 425 and 400 day-℃, respectively, while females 477, 411 and 404 day-℃, respectively. Cumulative mortality of the mealybug on tomato at 15 and 35℃ were 100%, on mung bean and hairy beggarticks at 15℃ was 100%, too. The lowest mortality on the three host plants were at 28℃, 25∼30℃ and 25∼30℃, respectively. The mean longevity of P. madeirensis decreased with increasing temperature. The highest fecundity was 67 eggs on tomato at 30℃, 493 eggs on mung bean at 28℃ and 141 eggs on hairy beggarticks at 25℃. Empty ovisac occurred at 28 and 32℃ on tomato, 32℃ on mung bean, and 30 and 32℃ on hairy beggarticks. The highest net reproductive rate (R0) on tomato was at 30℃, on mung bean at 28℃, and 25℃ on hairy beggarticks. The highest intrinsic rate of natural increase (rm ) was 0.0282, 0.0679 and 0.0229 respectively on tomato and mung bean at 30℃ and on hairy beggarticks at 25℃. Accordingly, the shortest doubling time (Dt) respectively on tomato and mung bean was 24.6 and 10.2 days at 30℃, and 30.3 days on hairy beggarticks at 25℃. The shortest mean generation time (T) was 28, 25 and 25 days at 30℃ on three plants, respectively. Thus, I concluded that the optimal range of temperature for P. madeirensis population growth was 25~30℃, and mung bean was the most suitable host plant among the three plants tested. But maybe hairy beggarticks was the most important host plant during the year.