Academic literature on the topic 'Soft-winged flower beetles'

The soft-winged flower beetles genus Cerapheles Mulsant et Rey, 1867 and species C. terminatus (Ménétriés, 1832) are recorded for the first time for Ukraine (Lviv and Volyn Regions). The habitats and host plants of adults of this species are characterized. The main morphological differences of Cerapheles from the related genus Anthocomus Erichson, 1840, as well as the redescription of male and the brief characteristics of female of C. terminatus are provided based on the current approaches in the soft-winged flower beetles taxonomy.

Soft-winged flower beetles (Coleoptera, Malachiidae), Apalochrus femoralis pallipes Motschulsky, 1860 and Ebaeus Erichson, 1840 species, are recorded for the first time from Quaternary fossils in the deposit Ustyanka-1 near Ustyanka river, the right tributary of Alei river in Altaiskii Krai, West Siberia, Russia. The strata containing malachiid fragments belong to the warm phase of the late glacial succession. It is shown that soft-winged flower beetles are typical of Holocene deposits and practically unknown from cold phases of the Pleistocene, except in the case of Protapalochrus Evers, 1987 which has been recorded from the Pleistocene. Illustrations of the external appearance of both male and female of the beetles, and sub-fossil remains of Apalochrus femoralis pallipes Motschulsky, 1860 and three species from the Ebaeus rufipes-group distributed in the region are given, together with details of their position within the Ustyanka-1 deposit. Data on the Malachiidae in Quaternary deposits of the Northern Hemisphere are briefly reviewed.

A new malachiid beetle genus, Anthomalachius gen. n., is described for Clanoptilus spinosus species group. Figures of male habiti, special structures, genitalia, and a distribution map for all species are given.

The Melyridae (soft-winged flower beetles) are a diverse, abundant, and widespread family of beetles found throughout the world, with more than 300 genera and 6000 species worldwide (Mayor 2002). Melyrids are particularly abundant in dry, temperate regions of the world. Mayor's (2002) synopsis of the North American fauna includes 58 genera and 520 species. Bright (1991) tabulates 49 species in 14 genera in the Canadian fauna. Only one species, the introduced Palearctic Malachius aeneus (L.), was reported for Atlantic Canada, with records in New Brunswick, Nova Scotia, and Newfoundland.

The relationship between beetles and flowers is often mutually beneficial. Flowers provide not only edible rewards and favourable micro-environments, but may also be sites for mating and egg-laying activities. Even though beetles consume various parts of flowers, including pollen, and can sometimes cause considerable damage, they are in fact important pollinators of many flowers. Pollen was once considered indigestible but is actually a highly nutritious food source for many animals (including insects, birds and mammals) which use a variety of methods to digest it. Six basic methods are discussed in detail: mechanical damage, piercing and sucking, external digestion, enzymatic action, osmotic shock and pseudogermination. In this study I investigated the mechanism and efficiency of pollen digestion of two different kinds of pollen, that of maize Zea mays and sunflower Helianthus annuus, by the spotted maize beetle Astylus atromaculatus (Melyridae) an economically important pest in South Africa Histological observations were made of the gut contents and faeces of spotted maize beetles that fed on maize and sunflower. A high percentage of maize pollen grains (88%) was found to be empty and ruptured in the anterior midgut of these beetles, while sunflower pollen, although the contents were removed from most of the grains (84%), remained intact. Osmotic shock was apparently involved in digestion of maize pollen while another method, such as enzymatic action, may be used for the digestion of sunflower pollen by this beetle. Digestion efficiency of pollen, which corrects for the number of initially empty grains, was determined for the spotted maize beetle (67% for sorghum, 72% for sunflower and 74% for maize) and was found to be high in comparison to values for various mammals, birds and insects consuming pollen of other plant species. Kroon et al. (1974) proposed osmotic shock as a prerequisite for pollen digestion in honeybees and this hypothesis was accepted into the literature without question. I investigated the effect of osmotic shock on maize pollen by looking at behaviour of pollen grains under varying osmotic concentrations. Given that rainwater can sometimes cause irreversible damage to pollen grains, distilled water was used to simulate rain and sucrose solutions the stigmatic exudates of flowers. A small number of studies have focused on differences between cultivars, therefore in vitro studies were carried out subjecting maize pollen of different cultivars to different sucrose and glucose:fructose concentrations, using distilled water as a control. Results of this study indicated that maize pollen might burst in distilled water and sugar solutions of various concentrations did not decrease the amount of rupturing compared to that in water. Few studies have looked at pollen of a single plant species being digested by different animals. I compared the efficiency and mechanism of maize pollen digestion by honeybees (Apis mellifera) and spotted maize beetles. Digestive efficiency was high (80%) in beetles compared to that of bees (21 %). Maize pollen bursts early in the midgut of maize beetles but remained intact in honeybees: this suggests that osmotic shock is not as important for bees as previously suggested.
Dissertation (MSc (Entomology))--University of Pretoria, 2006.
Zoology and Entomology
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