Capsazepine is a competitive antagonist of capsaicin, a TRPV1 agonist responsible for the spicy taste of pepper. TRPV1 agonists and antagonists are known to affect mammalian body temperature, but their action on thermoregulation in insects is poorly known. In this study we evaluated the effect of capsazepine on the thermal preference of the American cockroach, Periplaneta americana using a thermal gradient. Our results revealed that capsazepine in submicromolar concentrations induces a preference for higher ambient temperatures when compared to the control insects. To assess whether capsazepine may act also as an antagonist of capsaicin in insects, we determined this insects' thermal behaviour when capsazepine was applied before capsaicin. The hypothermic response to capsaicin was clearly blocked by pre-treatment with capsazepine only in female American cockroaches. Our results indicate the involvement of structures functionally similar to TRPV1 in insect thermosensation., Justyna Maliszewska, Eugenia Tęgowska., and Obsahuje bibliografii
We investigated the variation in body colour and its thermoregulatory function in Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae), a parasitoid wasp of Spodoptera and other free-living lepidopteran larvae. We show that the body colour of adult wasps darkens when cocoons are kept at low temperatures. The range in the variation in colour, however, differs for different parts of the body and among uniparental (thelytokous) strains. This melanism enables these wasps to attain a body temperature in sunshine up to 2°C. Moreover, this small gain in body temperature can markedly increase the flight activity of wasps at low ambient temperatures. We conclude that the variation in body colour that resulted from rearing the cocoons at different temperatures enable the wasps to adapt to changing thermal environments. The ecological significance of the difference in the degree of melanism of the different strains is discussed., Yosuke Abe, Takuma Nishimura, Kaoru Maeto., and Seznam literatury
The term cellular immune response refers to haemocyte-mediated responses, including phagocytosis, nodulation, and encapsulation. In the present study, we identified five types of circulating haemocytes in larvae of the haemolymph of the Asian corn borer, Ostrinia furnacalis (Guenée), including granulocytes, oenocytoids, plasmatocytes, prohaemocytes, and spherulocytes. The relative number of total free haemocytes per larva decreased significantly 0.5, 24, and 36 h after the injection of Beauveria bassiana conidia. Upon conidia challenge, both phagocytosis and nodulation were observed in the collected haemolymph from O. furnacalis larvae. In addition, plasma was found to be necessary for both phagocytosis and nodulation. Therefore, we here confirm that phagocytosis and nodulation are involved in O. funacalis larvae during their fight against infection by B. bassiana, and further, that the cellular immune response of O. furnacalis helps eliminate the invading organisms despite the fact that not all the fungal conidia are killed., Dongxu Shen, Miao Li, Yuan Chu, Minglin Lang, Chunju An., and Obsahuje bibliografii
Currently it remains difficult to obtain robust microsatellite markers for Lepidoptera. In an attempt to overcome the problems associated with developing microsatellite markers for this insect order we combined (i) biotin-enrichment protocol, (ii) next generation pyrosequencing (through 454 GS-FLX Titanium technology) and (iii) the use of individuals collected from eight geographically distant European populations representing three subspecies of Euphydryas aurinia. Out of 96 stringently designed primer pairs, 12 polymorphic microsatellite loci amplified without obvious evidence of null alleles in eight individuals from different subspecies. Between five and seven of these loci showed full within population applicability and three revealed to be robust and transferable between populations and sub-species, providing a first step towards the development of a valuable and robust tool for studying conservation issues and evolution in E. aurinia populations. Nevertheless, as in most studies dealing with Lepidoptera microsatellites, null alleles were detected in most of the developed markers. Our results emphasize the need for further research in order to better understand the complex evolution and organization of Lepidopteran genomes. and Melthide Sinama, Vincent Dubut, Caroline Costedoat, André Gilles, Marius Junker, Thibaut Malausa, Jean-François Martin, Gabriel Nève, Nicolas Pech, Thomas Schmitt, Marie Zimmermann, Emese Meglécz.
Because nutrients accrued during larval stages represent the major limiting factor for egg production, the use of adult feeding to enhance the reproductive output in moths is considered to be largely weight-dependent. It is hypothesized, however, that feeding by adults could be adaptive and an effective means of increasing their reproductive success. In order to test this, the calling behaviour of Spodoptera littoralis females that differed in body weight and whether they had fed or not were recorded. Two experiments were carried out. In the first, the calling behaviour of food-deprived females of different body weights was recorded. A strong positive correlation was found between body weight at emergence and the total duration of calling of females on the second to the fifth night after emergence. In the second experiment, groups of female moths that varied in body weight were given access to water or sucrose. Feeding on sucrose significantly reduced the pre-calling period and increased the total time spent calling on the six nights after emergence. The increase in time spent calling associated with ingesting sucrose were proportionately similar for both small and large females, implying that feeding by adults can result in an increase in the time spent calling by moths irrespective of larval nutritional status. Female longevity was also correlated with moth weight at emergence and/or sucrose availability. It is concluded that it is advantageous for female S. littoralis to be large and/or have access to sucrose-rich food in the adult stage as they can spend more time attracting a mate, which increases their chances of mating in early adult life, and their longer adult life may indirectly result in an increase in fecundity., Medhat M. Sadek., and Obsahuje seznam literatury
Climatic conditions can modify the life history traits, population dynamics and biotic interactions of species. Therefore, adaptations to environmental factors such as temperature are crucial for species survival at different altitudes. These adaptive responses, genetically fixed or plastic (phenotypic plasticity), can be determined by physiological thresholds and might vary between sexes. The objective of this study was to determine whether the life history traits of the European Map butterfly (Araschnia levana) differ at different altitudes. A field experiment was carried out along an altitudinal gradient from 350 to 1010 m a.s.l. in a low mountainous region (Bavaria, Germany). 540 butterfly larvae were placed at different altitudes in 18 planted plots of their larval host plant, the stinging nettle (Urtica dioica). After three weeks the larvae were collected and reared under laboratory conditions. Developmental traits of the butterflies, mortality and percentage parasitism were measured. Larval development was generally slower at higher altitudes and lower temperatures and larval weight decreased with increasing altitude and decreasing temperature. However, there were no significant differences in pupation, adult lifespan and percentage mortality at the different altitudes and temperatures. Female larvae were heavier than those of males, and the pupal and adult lifespans were longer in females than in males. However, male and female butterflies reacted similarly to altitude and temperature (no significant interactions). None of the 188 larvae collected were parasitized. In conclusion, the phenotypic plasticity of European Map butterfly has enabled it to adapt to different temperatures, but the strategies of the sexes did not differ. and Kathrin D. Wagner, Jochen Krauss, Ingolf Steffan-Dewenter.
Chromosomes of the males of five species of Odontura, belonging to the subgenera Odontura and Odonturella, were analyzed. Intensive evolution of the karyotype was recorded, both in terms of changes in the numbers of chromosomes (from 2n = 31 to 27) and the sex chromosome system (from X0 to neo-XY and X0 to neo-X1X2Y). Karyotype evolution was accompanied by tandem autosome fusions and interspecific autosomal and sex chromosome differentiation involving changes in the locations of nucleolar organizer regions, NORs, which were revealed by silver impregnation and confirmed by FISH using an 18S rDNA probe. O. (Odonturella) aspericauda is a polytypic species with X0 and neo-X1X2Y sex determination. The latter system is not common in tettigoniids. It possibly originated by a translocation of a distal segment of the original X chromosome onto a medium sized autosome, resulting in a shortened neo-X1 and a metacentric neo-Y. The remaining autosome homologue became the neo-X2 chromosome. This shift from X0 to neo-X1X2Y is supported by the length of the X chromosome and location of the NOR/rDNA. and Elżbieta Warchałowska-Śliwa, Anna Maryańska-Nadachowska, Beata Grzywacz, Tatjana Karamysheva, Arne W. Lehmann, Gerlind U.C. Lehmann, Klaus-Gerhard Heller.
The oriental fruit fly, Bactrocera dorsalis, is a key economic insect pest reducing fruit yield and generating constraints in the international market. The application of the sterile insect technique (SIT) continues to reveal areas where new technologies can improve the effectiveness of fruit fly control. One such advancement concerns insect strains. In the present study, a mass-reared strain of the fly with a translocation-based genetic sexing character (Salaya1) based on a brown-white pupal colour dimorphism was genetically characterized using 11 microsatellite DNA markers. Subsequently, these markers were used to evaluate the maintenance of genetic variability in the strain under mass-rearing conditions. Mating competitiveness of this strain was also tested in field cages. Two of the newly characterized Y-pseudo-linked microsatellite markers were used for strain identification in field monitoring traps. The strain was also validated in a pilot integrated pest management (IPM) programme using male-only SIT in a fruit orchard. The programme resulted in the suppression of the fruit fly population., Siriwan Isasawin, Nidchaya Aketarawong, Sujinda Thanaphum., and Obsahuje seznam literatury