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Ladybird Coccinella septempunctata (Coleoptera: Coccinellidae) prefers toxic prey in laboratory choice experimentOldøich NEDVÌD, Sara SALVUCCIEur. J. Entomol. 105 (3): 431-436, 2008 | DOI: 10.14411/eje.2008.055 In a laboratory experiment, we investigated the preference of larvae and adults of Coccinella septempunctata (Coleoptera: Coccinellidae) for three aphid species: two essential prey, Acyrthosiphon pisum and Aphis philadelphi, and a toxic prey Aphis sambuci. Surprisingly, the toxic aphid was consumed at twice the rate of the two essential prey species. The stages and genders of the ladybirds did not differ in their preference for aphid species. In the tritrophic interaction, in the field, on the elder host plant Sambucus nigra, A. sambuci is usually avoided by C. septempunctata. To measure ladybird preference, apterous females of the three selected aphid species were released in a Petri dish followed by a ladybird. After four hours, we removed the ladybird, counted the number of aphids of each species that survived, and calculated the number of aphids of each species consumed in total. We examined preference by considering separately the first two aphids consumed by a predator (early feeding), and all remaining aphids consumed thereafter (late feeding). The consumption rates of the first two individuals did not deviate from expected values with no preference; i.e., ladybirds fed on aphids without choice in the beginning of experiment when they were hungry. The ladybirds did express preference thereafter, but our hypothesis that the ladybirds should be able to distinguish among the aphids during later phase of the experiment and choose the most profitable species, or at least distinguish between essential and toxic prey, was rejected. |
Initial preference of oviposition sites: discrimination between living and dead plant material in Sympecma fusca and Coenagrion caerulescens (Odonata: Lestidae, Coenagrionidae)Andreas MARTENSEur. J. Entomol. 98 (1): 121-123, 2001 | DOI: 10.14411/eje.2001.021 Sympecma fusca and Coenagrion caerulescens mainly deposit their eggs into floating dead parts of emergent plants. In their initial choice of oviposition site (selection of landing site) S. fusca does not distinguish between fresh and dead plant material, whereas C. caerulescens significantly prefers dead material. In S. fusca, the missing discrimination of the plant condition in the choice of the landing site is explained by its oviposition period in the beginning of the vegetation period when the green plant material is rare. C. caerulescens reproduces in summer and finds dead and living plants side by side. I suggest that in the latter species an early recognition of dead material is advantageous because of the reduction of the expense in searching. |
Latitudinal variation in morphology in two sympatric damselfly species with contrasting range dynamics (Odonata: Coenagrionidae)Christopher HASSALL, David J. THOMPSON, Ian F. HARVEYEur. J. Entomol. 105 (5): 939-944, 2008 | DOI: 10.14411/eje.2008.120 Geographic range expansion is one of the best documented macroecological consequences of climate change. A concomitant change in morphology has been demonstrated in some species. The relationship between latitudinal variation in morphology (e.g. Bergmann's rule) and the morphological consequences of microevolutionary pressures at expanding range margins have received little attention in the literature. Here we compare morphology of males of two Palaearctic damselfly (Odonata: Zygoptera) species, Coenagrion puella (Linnaeus, 1758) and Pyrrhosoma nymphula (Sulzer, 1776). C. puella has recently expanded its range from the north of England into Scotland. P. nymphula does not exhibit a range margin in the United Kingdom and has established populations in northern Scotland. We demonstrate evidence for spatially correlated variation in body size across the sampling sites between the two species but a deviation in patterns of dispersal-related morphology. P. nymphula exhibited very weak relationships between dispersal-related morphology (wing loading and thorax : abdomen mass ratio) and latitude. However, the more southerly-distributed C. puella exhibited strong relationships between mass investment in dispersal-related morphology and latitude. These trends appear to indicate compensatory growth patterns in cooler environments like those demonstrated for other species. The limits of this compensation for conditions that are close to the limits of a species' tolerance may contribute to the determination of the range margin. Greater variation in morphology towards the range margin has been observed in previous studies in Odonata. As such, the location of the sampling sites relative to the range margin of each species (closer in C. puella than P. nymphula) is highlighted as a potential contributing factor to the variation observed. |
Introducing barley as aphid reservoir in sweet-pepper greenhouses: Effects on native and released hoverflies (Diptera: Syrphidae)Ana PINEDA, María ÁNGELES MARCOS-GARCÍAEur. J. Entomol. 105 (3): 531-535, 2008 | DOI: 10.14411/eje.2008.070 Habitat management is a form of conservation biological control, that includes strategies such as the provision of alternative prey for natural enemies. One example is the "banker plants" strategy, which consists of introducing cereals with aphids in horticultural crops. It is usually combined with parasitoid releases. In this work we evaluated whether aphid-infested barley as "banker plants" enhances native populations of aphidophagous syrphids and extends the residence time of Episyrphus balteatus (De Geer) following release. The work was performed in four replicated sweet-pepper commercial greenhouses in the southeast of Spain. Barley was sown, and infested with the aphid Rhopalosiphum maidis (Fitch). Visual censuses were performed to record released individuals of E. balteatus (marked on the thorax before release) and naturally occurring hoverflies. At the end of the experiment leaf samples were taken to the laboratory, and the immature syrphids were reared for identification. The occurrence of syrphids that come from outside the greenhouse was significantly increased by the presence of the infested barley plants. From a total of 506 observations of adult native syrphids, 81% were Sphaerophoria rueppellii (Wiedemann). We did not find significant differences between control plots and those provided with banker plants in their probabilities to retain released specimens of E. balteatus. Of the syrphids collected at immature stages from the barley leaves, we did not record any E. balteatus, and 100% of the specimens were identified as S. rueppellii. We conclude that the banker plant strategy is effective in attracting natural populations of syrphids into sweet pepper greenhouses, but not in keeping released individuals of E. balteatus in the greenhouses long enough to lay eggs. We suggest that the E. balteatus release method should be amended. |
Trophic egg provisioning in a passalid beetle (Coleoptera)Kyoko ENTO, Kunio ARAYA, Shin-Ichi KUDOEur. J. Entomol. 105 (1): 99-104, 2008 | DOI: 10.14411/eje.2008.014 Trophic eggs, which are not viable and eaten by larvae, are produced by the passalid beetle Cylindrocaulus patalis. This is the first record of trophic eggs in subsocial Coleoptera. There are differences in the morphology of trophic and fertile eggs; the former are a paler colour and softer than the latter. The surface of the chorion of trophic eggs is also smoother than that of fertile eggs. The trophic eggs are fed directly by the female parent to 3rd instar larvae following a series of specific behavioural interactions between them, including repeated stridulation by the larva. It is likely that trophic eggs supplement the protein-poor diet of the larvae and contribute to their growth and survival. The production of trophic eggs may be associated with the evolution of an extremely small clutch size in C. patalis. |
Variation in dung beetle (Coleoptera: Scarabaeoidea) assemblages with altitude in the Bulgarian Rhodopes Mountains: A comparisonJorge M. LOBO, Evgeni CHEHLAROV, Borislav GUÉORGUIEVEur. J. Entomol. 104 (3): 489-495, 2007 | DOI: 10.14411/eje.2007.069 Variation with altitude in the composition of dung beetle assemblages and species richness was measured by sampling in spring, summer and autumn, both manually and with pitfall traps at twelve localities in the western Rhodopes Mountains. Non-parametric estimates indicate that most of the regional species pool was collected, some 73% of all taxa previously recorded in the entire region. The rate of species richness decrease with altitude is around 11 species per km, with an evident altitudinal change in the incidence of two main dung beetle functional groups in which Aphodiinae species begin to dominate Rhodopes assemblages at around 1400-1500 m. Species richness of dung pats is dominated by Scarabaeinae in spite of the fact that the number of Aphodiinae species is highest at each locality. Thus, Aphodiinae species are the main contributors to both local and regional pool richness and to species turnover between localities. These characteristics are similar to those observed in the assemblages from another European mountain range, also located near the Mediterranean-Eurosiberian boundary, the Iberian Central System. These results suggest that eastern European dung beetle assemblages are similar in compositional turnover and species richness variation with altitude to that observed in western Europe and North America. |
Role of volatile and contact pheromones in the mating behaviour of Bagrada hilaris (Heteroptera: Pentatomidae)Salvatore GUARINO, Claudio DE PASQUALE, Ezio PERI, Giuseppe ALONZO, Stefano COLAZZAEur. J. Entomol. 105 (4): 613-617, 2008 Volatiles and contact pheromones involved in the mating behaviour of the Painted bug, Bagrada hilaris Burmeister (Heteroptera: Pentatomidae), were investigated in behavioural and chemical experiments. Vertical open Y-shaped olfactometer bioassays showed that odour from males attract females but not males, while that from females did not attract either gender. Adult females were also attracted by hexane extracts of volatile compounds collected from males. In open arena bioassays, males displayed the characteristic steps of courtship behaviour in the presence of virgin females. Such courtship behaviour was displayed in the presence of females killed by freezing, but not in the presence of freeze-killed females washed with hexane. Gas chromatography-mass spectrometry (GC-MS) analysis of volatile compounds produced by cohorts of 20 B. hilaris adults and collected over 48 h showed that both males and females produce the compounds nonanal, decanal and (E)-2-octenyl acetate. Of these compounds males produce significantly more (E)-2-o-octenyl acetate, i.e. 186.74 ng and 67.53 ng for males and females respectively. These findings indicate this compound is possibly a long range volatile pheromone, and a complex lipophilic fraction of the adult cuticle possible contact pheromone involved in short range courtship behaviour. |
Revision of Phaeochiton Kerzhner, 1964 (Heteroptera: Miridae: Phylini)Fedor V. KONSTANTINOVEur. J. Entomol. 105 (4): 771-781, 2008 The genus Phaeochiton Kerzhner, 1964 is revised and P. alenae sp. n. from Mongolia is described. Differential diagnoses are provided for the genus and its three species. Illustrations of male and female genitalia, tarsus and pretarsus, photographs of the dorsal habitus, hosts, and distributional records of the species discussed are given. |
The effect of the quality and size of host aphid species on the biological characteristics of Aphidius colemani (Hymenoptera: Braconidae: Aphidiinae)Marcus Vinicius SAMPAIO, Vanda Helena Paes BUENO, Bruno Freitas DE CONTIEur. J. Entomol. 105 (3): 489-494, 2008 | DOI: 10.14411/eje.2008.063 A suitable host provides, at least, the minimum nutritional and physiological conditions for the development of the immature stages of a parasitoid. Host quality may influence the developmental time, mortality rate, longevity and fecundity of parasitoids. This work evaluates the suitability and quality of Aphis gossypii Glover, Brevicoryne brassicae (Linné), Myzus persicae (Sulzer), Rhopalosiphum maidis (Fitch) and Schizaphis graminum (Rondani) as hosts for Aphidius colemani Viereck. Twenty second-instar nymphs of each aphid species were exposed to parasitism for one hour, and then kept in a climatic chamber at 22 ± 1°C, 70 ± 10% RH and a 12 h photophase. The aphid B. brassicae was unsuitable for the development of A. colemani. The different aphid host species varied in size: M. persicae > (R. maidis = S. graminum) > A. gossypii. Parasitoid fitness decreased accordingly when reared on (M. persicae = R. maidis) > S. graminum > A. gossypii. Large hosts seem to be better than small hosts based on parasitoid size. Egg load of A. colemani was related probably more on the ability of the parasitoid larva to obtain nutritional resources from the different host species than on host size. |
Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)Pablo C. COLOMBOEur. J. Entomol. 104 (4): 653-659, 2007 | DOI: 10.14411/eje.2007.082 The New World grasshopper Cornops aquaticum (Leptysminae: Acrididae) shows a geographical pattern for three Robertsonian polymorphisms in its southernmost area of distribution in Argentina and Uruguay. The frequency and distribution of chiasmata were analysed in five Argentinian populations. This study reveals a strong redistribution of chiasmata in fusion carriers, with a reduction in proximal and increase of distal chiasma frequency in fusion bivalents and trivalents, when all three karyotypes were compared. However, when only fusion bivalents and trivalents were compared, chiasma frequency was significantly higher in the former than in the latter. This higher chiasma frequency in fusion bivalents is due to an increase in proximal chiasma frequency. It is argued that the reduction in proximal chiasma frequency (relative to unfused bivalents) in fusion bivalents may be due to interference across the centromere. Proximal chiasma reduction in trivalents may be attributed either to a physical effect of structural heterozygosity or to an adaptation to the polymorphic condition. Therefore the differences in the distribution of chiasmata in trivalents and Robertsonian bivalents have different causes. |
Spermathecal morphology and sperm dynamics in the female Schizocosa malitiosa (Araneae: Lycosidae)Gonzalo USETA, Bernhard A. HUBER, Fernando G. COSTAEur. J. Entomol. 104 (4): 777-785, 2007 | DOI: 10.14411/eje.2007.099 The linkage between spermathecal morphology and sperm dynamics was experimentally analysed in Schizocosa malitiosa (Tullgren, 1905) using histological serial sections and SEM. We recognised three connected sections for each spermatheca: basal atrium, stalk and head. The head ends blindly, is sclerotized, provided with few large pores, and surrounded by thick, presumably glandular epithelium. The atrium is also sclerotized, and connects with both copulatory and fertilization ducts, lying close to each other. A porous plate is located in the stalk-atrium connection. Nine adult females were fixed in eight reproductive conditions for reconstructing sperm dynamics: virgin, immediately after mating, one day after mating, three days after mating, one day after remating without oviposition (first male with a single useful palp, second male normal), immediately before oviposition, three days after oviposition, and one day after remating with oviposition (female had eaten first egg-sac and had remated). Our results suggest female control of sperm transport because the penetration of encapsulated sperm into the spermathecal head continues after mating. Stored sperm is maintained in an encapsulated condition until oviposition, when sperm is totally activated. Sperm cells may remain viable for a long time in the decapsulated state. There was evidence for sperm mixing in the female that remated after oviposition. |
Moist habitats are essential for adults of the Antarctic midge, Belgica antarctica (Diptera: Chironomidae), to avoid dehydrationJoshua B. BENOIT, Giancarlo LOPEZ-MARTINEZ, Michael A. ELNITSKY, Richard E. LEE, David L. DENLINGEREur. J. Entomol. 104 (1): 9-14, 2007 | DOI: 10.14411/eje.2007.002 Desiccation resistance of adult males and females of the midge, Belgica antarctica (Diptera: Chironomidae) was evaluated to determine how this short-lived stage maintains water balance in the dry Antarctic environment. Both sexes had slightly lower water content (≈60%) and a higher dehydration tolerance (>30% water loss) than most other insects. Water loss rates were high and increased rapidly at temperatures above 15°C, indicating that the adult midges are more hygric than many other polar terrestrial arthropods. Water gain was accomplished by free water uptake with minimal or no contribution from absorption of water vapor or metabolic water production. Parameters related to water balance did not differ among populations from different islands. Overall, the high water requirements of the adult midge appear to be a significant challenge and presumably dictate that the adult midges must emerge during the brief period when free water is readily available and seek protected microhabitats that facilitate water retention. |
Redefinition of the Clusiinae and Clusiodinae, description of the new subfamily Sobarocephalinae, revision of the genus Chaetoclusia and a description of Procerosoma gen. n. (Diptera: Clusiidae)Owen LONSDALE, Stephen A. MARSHALLEur. J. Entomol. 103 (1): 163-182, 2006 | DOI: 10.14411/eje.2006.020 The higher classification of the Clusiidae is reviewed, and the family is divided into the subfamilies Clusiodinae, Clusiinae and the new subfamily Sobarocephalinae, all of which are (re)defined. The newly defined Clusiinae includes the genera Phylloclusia Hendel, 1917, Tetrameringia McAlpine, 1960, Amuroclusia Mamaev, 1987, Clusia Haliday, 1838, Paraclusia Czerny, 1903, Alloclusia Hendel, 1917 and Apiochaeta Czerny, 1903. The Sobarocephalinae includes the genera Sobarocephala Czerny, 1903, Procerosoma gen. n., and Chaetoclusia Coquillett, 1904. The new genus Procerosoma is described for two species, Procerosoma alini (Shatalkin) comb. n. from Brazil and P. prominens sp. n. from Mexico. Sobarocephaloides Soós, 1962 is treated as a junior synonym of Sobarocephala, and Chaetoclusia is redefined to include the monotypic genera Chaetoclusiella Soós, 1962, syn. n. and Trichoclusia Soós, 1962, syn. n. Six new species of Chaetoclusia are described (C. centrofasciata sp. n., C. amplipenis sp. n., C. transversa sp. n., C. inbionella sp. n., C. flava sp. n., and C. furva sp. n.). Chaetoclusia bakeri peruana Hennig, 1938 is included as a junior synonym of C. bakeri Coquillett, 1904. The phylogeny of Chaetoclusia is discussed and a key is provided for its 13 species. |
Morphology and ultrastructure of the male reproductive system of the woolly beech aphid Phyllaphis fagi (Hemiptera: Aphididae: Phyllaphidinae)Karina WIECZOREK, Piotr SWI¡TEKEur. J. Entomol. 105 (4): 707-712, 2008 In the present paper we describe for the first time the ultrastructure of the male reproductive system of aphids using Phyllaphis fagi as a representative. Paired testes of this species consist of three follicles each, arranged in a rosette, the walls of the proximal part of vasa deferentia cling together, accessory glands are club-shaped and elongated whereas the ejaculatory duct is reduced. Our study also shows that vasa deferentia, accessory glands and ejaculatory duct are histologically very simple. All of them are composed of cubical epithelium of secretory type. The epithelial cells are rich in rough endoplasmic reticulum, Golgi complexes and produce small heterogeneous vacuoles. The apical membrane of these cells forms microvilli. The reproductive system epithelia stand on thin basal lamina. Outside the basal lamina thin muscle fibres are observed. Histochemical staining shows that secretion filling the lumen of vasa deferentia and accessory glands contains proteins and polysaccharides. |
Effects of larval diet on female reproductive output of the European coccinellid Adalia bipunctata and the invasive species Harmonia axyridis (Coleoptera: Coccinellidae)Remy L. WARE, Benjamin YGUEL, Michael E.N. MAJERUSEur. J. Entomol. 105 (3): 437-443, 2008 | DOI: 10.14411/eje.2008.056 Cannibalism and intraguild predation (IGP) are both common phenomena amongst aphidophagous coccinellids and serve as vital alternative feeding strategies which can prolong survival during periods of aphid scarcity. A reduction in essential prey density and the acceptance of conspecific or heterospecific prey are likely to have a considerable influence on both larval development and adult reproduction. However, little is known about the legacy of larval diet on adult performance. This paper considers the effects of the diet provided to larvae of Harmonia axyridis (Pallas) and Adalia bipunctata (Linnaeus) (Coleoptera: Coccinellidae) on the reproductive output of the resulting females. Results showed that larval diets, including treatments analogous to competition and IGP, did not affect adult longevity, ovipositional lag, proportion of eggs laid in clutches or ovariole number in H. axyridis or A. bipunctata. However, some variation in the maximum clutch size and oviposition rate was seen. A larval diet of unlimited aphids resulted in the largest clutches of eggs being laid by both species. The total number of eggs laid over 30 days was largest for H. axyridis when larvae were reared on unlimited aphids or limited aphids supplemented with either conspecific or heterospecific eggs, whereas oviposition was lower for A. bipunctata females that had received conspecific or heterospecific eggs in their larval diets. The results have also enabled us to make some general comparisons of reproductive parameters between the two species, and to refute the hypothesis that the maximum clutch size laid by a female ladybird is limited by the number of ovarioles within an ovary. We conclude that IGP of A. bipunctata eggs by H. axyridis larvae has a positive effect on reproductive output and is therefore likely to further contribute to the spread and increase of H. axyridis in Britain. |
Seasonal activity-profiles of enzymes involved in cryoprotectant biosynthesis in Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)Michaela TOLLAROVÁEur. J. Entomol. 105 (1): 149-152, 2008 | DOI: 10.14411/eje.2008.020 The activities of three enzymes involved in polyol biosynthesis (aldose reductase, AR; ketose reductase, KR; and polyol dehydrogenase, PDH) were studied in adult females of the linden bug, Pyrrhocoris apterus, collected from the field during 2005/2006. While the activities of three enzymes were low in reproductive females, activities greater by one or two orders were seen in reproductively arrested females. AR and KR showed similar seasonal trends in activity. Activities were low during diapause initation and later increased and stabilized during autumnal diapause development. Further increases of AR and KR activities were seen during low temperature quiescence and finally the activities sharply decreased during vernal resumption of direct development. The activity of PDH was relatively high (but fluctuating) during diapause, then decreased in quiescent insects and almost disapeared in reproductively active females. Insects collected in February were subjected to laboratory de-acclimation (exposure to high temperatures) followed by re-acclimation (exposure to low temperatures) which resulted in loss of activity in all three enzymes and no regain. High activities of AR, KR and PDH in reproductively arrested females thus conform well with their previously observed high capacity to synthesize and accumulate polyol cryoprotectants. |
Cleorodes Warren, 1894 does not belong in the tribe Boarmiini (Lepidoptera: Geometridae)Jaan VIIDALEPP, Toomas TAMMARU, Niina SNÄLL, Kai RUOHOMÄKI, Niklas WAHLBERGEur. J. Entomol. 104 (2): 303-309, 2007 | DOI: 10.14411/eje.2007.046 The geometrid genus Cleorodes is shown to belong in the tribe Gnophini (sensu lato) and not in Boarmiini as previously assumed. The conclusion is based on an analysis of morphological characters of a number of genera in these tribes. Moreover, the result is unambiguously supported by a phylogenetic analysis of DNA sequence variation in three nuclear gene regions (segments D1 and D2 of 28S rRNA, and elongation factor 1α) and a mitochondrial gene, cytochrome oxidase-1. The phylogenetic hypothesis is based on a combined sequence data set, which was analysed using direct optimisation. |
Microsatellites for the highly invasive Cameraria ohridella (Lepidoptera: Gracillariidae) and their amplification in related speciesNeus MARI MENA, Romain VALADE, Emmanuelle MAGNOUX, Sylvie AUGUSTIN, Carlos LOPEZ-VAAMONDEEur. J. Entomol. 105 (5): 945-948, 2008 | DOI: 10.14411/eje.2008.121 A set of six polymorphic microsatellite markers was developed for the highly invasive horse chestnut leaf-mining moth, Cameraria ohridella. For 96 positive clones, six polymorphic microsatellites with conserved flanking regions were identified. The average number of alleles per locus was eight (range from three to 12). Two of these loci showed significant heterozygosity deficits due to null alleles. The remaining four loci did not depart from Hardy-Weinberg equilibrium. In addition, all six loci were amplified for 20 other gracillariid species belonging to eight different genera, including another invasive species Phyllonorycter platani. These are the first microsatellite markers described for a species within the lepidopteran family Gracillariidae. |
Molecular differentiation of the four most commonly occurring Trichogramma (Hymenoptera: Trichogrammatidae) species in ChinaZheng-Xi LIEur. J. Entomol. 104 (3): 363-367, 2007 | DOI: 10.14411/eje.2007.054
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Faunal patterns in Tuscan archipelago butterflies (Lepidoptera): The dominant influence is recent geography not paleogeographyLeonardo DAPPORTO, Alessandro CINIEur. J. Entomol. 104 (3): 497-503, 2007 | DOI: 10.14411/eje.2007.070 The aim of this paper is to examine whether current and/or Pleistocene geography affect the species richness and composition of Tuscan archipelago butterflies. This archipelago is located between Tuscany (Italy) and Corsica (France). Faunistic data was obtained from the literature and surveys. Our data revealed that contemporary geography is the most important factor determining the species richness and faunal composition of Tuscan archipelago butterflies. Indeed, current area and isolation of the islands are the only predictors significantly correlated with species richness. Paleogeographic features of the archipelago are not significantly correlated with species richness. Multidimensional scaling revealed patterns similar to those reported for other living groups. Specifically, Capraia and Montecristo group together with Corsica, while Elba, Giglio, Pianosa, Gorgona, Giannutri and the fossil island of Monte Argentario group with the Tuscan mainland. Recent geography seems to affect the faunal composition. Indeed Mantel test indicates that the similarity in the faunal composition of the Tuscan Archipelago islands is mainly related to present-day island characteristics and their relative distance from Tuscany and Corsica. Our results are similar to those recently obtained for Aegean archipelago butterflies. |
Role of olfactory and visual stimuli in the mating behaviour of male vine bud moths, Theresimima ampellophaga (Lepidoptera: Zygaenidae)Teodora Borislavova TOSHOVA, Mitko Angelov SUBCHEV, Miklós TÓTHEur. J. Entomol. 104 (1): 57-65, 2007 | DOI: 10.14411/eje.2007.009 The influence of olfactory and visual stimuli on the mating behaviour of Theresimima ampellophaga males was investigated in the field. A female model attached to a pheromone source significantly increased the number of males contacting and showing copulatory responses compared to their reaction to a pheromone stimulus alone. The pheromone stimulus was the primary factor releasing male copulatory behaviour, independent of the spatial arrangement of olfactory and visual cues. The role of the visual cues decreased with increasing distance between visual and olfactory cues. The reaction of males to pairs of models with different characteristics of conspecific females, in combination with a pheromone source placed 2 cm upwind from the center of the line between each pair of models, was compared. The size and shape of the female seemed not to be important, while the colour, posture, sex and species belongings significantly influenced the male's mating reaction. |
Effect of larval crowding on the life history traits of Sesamia nonagrioides (Lepidoptera: Noctuidae)Argyro A. FANTINOU, Dionyssios C. PERDIKIS, Nikolaos STAMOGIANNISEur. J. Entomol. 105 (4): 625-630, 2008 This study determined the effect of larval density-dependent competition for food on development and adult fitness in Sesamia nonagriodes Lef. (Lepidoptera: Noctuidae). Different numbers (5, 10, 15, 20 and 30 individuals) of larvae of the pink stalk borer were reared on a constant amount of food. Although crowding during the immature stages did not significantly increase mortality, it prolonged the larval developmental period and resulted in reduced pupal weight. Females were more adversely affected by high density than males, resulting in lighter females, indicating that female growth is more sensitive to density. The fecundity of the adults reared in the various larval crowding treatments was analysed. Total female fecundity was correlated negatively with increasing larval density. The effects of crowding on fecundity were not caused by the reduced pupal weight, indicating that food shortage during larval development may affect adult traits. Female longevity was negatively affected by density and positively related to pupal weight. Thus, larval density may affect the allocation of food resources and adult fitness. We conclude that crowding related changes during larval development directly affect larval life and reduce female fitness. |
A new genus of isophlebioid damsel-dragonflies with "calopterygid"-like wing shape from the Middle Jurassic of China (Odonata: Isophlebioidea: Campterophlebiidae)André NEL, Di-Ying HUANG, Qi-Bin LINEur. J. Entomol. 105 (4): 783-787, 2008
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Intronic sequences of the silkworm strains of Bombyx mori (Lepidoptera: Bombycidae): High variability and potential for strain identificationKee Young KIM, Eun Lee MEE, In Lee HEE, Mee Hong YEON, Pil Don KANG, Kwang Ho CHOI, Zhong Zheng GUI, Byung Rae JIN, Jae Sam HWANG, Kang Sun RYU, Yeon Soo HAN, Iksoo KIMEur. J. Entomol. 105 (1): 73-80, 2008 | DOI: 10.14411/eje.2008.010 We sequenced nine introns of 25 silkworm (Bombyx mori L.) strains, assuming that the introns are particularly prone to mutation. Mean sequence divergence and maximum sequence divergence in each intronic sequence among 25 silkworm strains ranged from 0.81% (3.8 nucleotides) ~ 9.15% (85.2 nucleotides) and 1.2% (seven nucleotides) ~ 39.3% (366 nucleotides), respectively. The degree of sequence divergence in some introns is very variable, suggesting the potential of using intronic sequences for strain identification. In particular, some introns were highly promising and convenient strain markers due to the presence of a large indels (e.g., 403 bp and 329 bp) in only a limited number of strains. Phylogenetic analysis using the individual or the nine concatenated intronic sequences showed no clustering on the basis of known strain characteristics. This may further indicate the potential of the intronic sequences for the identification of silkworm strains. |
Geographical versus food plant differentiation in populations of Maculinea alcon (Lepidoptera: Lycaenidae) in Northern HungaryJudit BERECZKI, Katalin PECSENYE, Zoltán VARGAEur. J. Entomol. 103 (4): 725-732, 2006 | DOI: 10.14411/eje.2006.096 The taxonomic status of Alcon Blues in Central and Western Europe (conventionally: Maculinea alcon and M. rebeli) is confused. Some authors distinguish them as separate species within the M. alcon species group, while others consider them to be subspecies or simply ecological forms. Our aim was to study the geographical versus food plant pattern of genetic differentiation among several populations of these taxa in Northern Hungary. Imagines were collected from 11 localities between 2000 and 2003. M. alcon feeding on G. pneumonanthe from three subregions and on G. cruciata from two subregions were analysed. Enzyme polymorphism was analysed at 16 enzyme loci using polyacrylamide gel electrophoresis. In the analysis of the data, F-statistics were computed and the total genetic variation partitioned into within and between population components. Nei's genetic distances were calculated and a UPGMA dendrogram constructed on the basis of the distance matrix. Hierarchical F-statistics and AMOVA were computed to study the pattern of genetic differentiation among the samples. PCA analysis was also carried out using the allele frequencies of the samples. The results of all analyses indicated strong differentiation among the samples. A sizeable portion of this variation was detected among the samples/generations collected from the same population. The distribution of the between population variation did not exhibit a clear split between the two food plant groups. In addition, the FST values computed using a restricted data set suggested significant differentiation among the subregions. The results of AMOVA and PCA also indicated that the geographic pattern was more expressed in the between sample variation than the conventional taxonomic pattern. |
Phylogeny and evolutionary history of queen polymorphic Myrmecina ants (Hymenoptera: Formicidae)Florian M. STEINER, Birgit C. SCHLICK-STEINER, Heino KONRAD, Timothy A. LINKSVAYER, Swee-Peck QUEK, Erhard CHRISTIAN, Christian STAUFFER, Alfred BUSCHINGEREur. J. Entomol. 103 (3): 619-626, 2006 | DOI: 10.14411/eje.2006.083 The phylogenetic relationships in the myrmicine ant genus Myrmecina were analyzed using 1,281 bp of the mitochondrial cytochrome c oxidase I gene. Intermorphic queens observed in M. graminicola (Europe), M. nipponica (Japan), M. americana (North America; reported for the first time) and M. sp. A (Java) were reconstructed as an ancestral trait in this genus. Molecular-clock-based age estimates suggest that queen polymorphism evolved in Myrmecina at the latest during the Miocene. In terms of biogeographical regions, the inferred chronological order of divergence is: (oriental, (nearctic, (western palearctic, eastern palearctic))). |
Regulation of the development of flight muscles in long-winged adults of the flightless bug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)Radomír SOCHA, Jan ©ULAEur. J. Entomol. 105 (4): 575-583, 2008 We studied the development of the indirect flight muscles and reproductive organs in long-winged (macropterous) adults of the flightless bug Pyrrhocoris apterus (L.) and the factors involved in flight muscles histolysis by means of total protein analysis. Both the extirpation of the corpus allatum, an endocrine gland that is the sole source of juvenile hormone, and sham operation accelerated histolysis and decreased the level of the total protein content of the flight muscles to the same extent. Degeneration of flight muscles was not a result of allatectomy but rather a consequence of injury, followed by resumption of enhanced food intake, because it was stimulated also by the removal of wings. Transfer of penultimate instar larvae to a diapause-inducing short-day photoperiod did not prevent imaginal growth and histolysis of flight muscles, but inhibited growth of ovaries in females and maturation of accessory glands in adult males. Thus inactivation of the corpus allatum in diapausing macropters does not prevent imaginal growth of their flight muscles. Application of a high dose of methoprene to the surface of intact long-day macropterous adults induced precocious histolysis of flight muscles and growth of ovaries in females and accessory glands in males. Prolonged starvation of macropterous adults had only a small effect on the histolysis of their flight muscles. The results indicate that imaginal growth and histolysis of indirect flight muscles in macropterous individuals of P. apterus are largely juvenile hormone-independent processes that are programmed to occur spontaneously, but can be affected by various internal and external factors. |
Rapid discrimination of the common species of the stored product pest Liposcelis (Psocoptera: Liposcelididae) from China and the Czech Republic, based on PCR-RFLP analysisMeng QIN, Zhi-Hong LI, Zuzana KUÈEROVÁ, Yang CAO, Václav STEJSKALEur. J. Entomol. 105 (4): 713-717, 2008 Psocids of the genus Liposcelis (Psocoptera: Liposcelididae) are stored product pests that are difficult to identify morphologically. A molecular method based on Restriction Fragment Length Polymorphism (RFLP) of the PCR-amplified 16S rDNA gene was developed for the rapid discrimination of four common species (L. bostrychophila, L. entomophila, L. decolor, and L. paeta). Different developmental stages and populations (P.R. China and Czech Republic) were tested. One DNA fragment of about 500 bp in length was amplified from genomic DNA and the fragment was then digested using the restriction endonuclease DraI. Identification of the relevant banding pattern allowed all the developmental stages and both sexes to be discriminated in the species tested. The banding patterns of L. entomophila from all populations were identical, while the relevant restriction digests and sequence analysis confirmed that the Chinese and Czech populations of L. bostrychophila, L. decolor, and L. paeta differed. In conclusion, PCR-RFLP with one pair of primers (16Sar and 16Sbr) and one restrictive endonuclease, DraI, proved a reliable method for rapidly discriminating the Liposcelis species tested. |
Sympatric coexistence of sibling species Harmonia yedoensis and H. axyridis (Coleoptera: Coccinellidae) and the roles of maternal investment through egg and sibling cannibalismNaoya OSAWA, Kazunori OHASHIEur. J. Entomol. 105 (3): 445-454, 2008 | DOI: 10.14411/eje.2008.057 The sibling species H. yedoensis Takizawa coexists sympatrically and simultaneously with H. axyridis only on pine trees in Japan. To elucidate the mechanisms enabling coexistence of these two sympatric sibling species, a laboratory experiment was performed that focused on differences in their maternal investment through eggs and the role of sibling cannibalism. The egg size (volume) of H. yedoensis was 24.91% larger than that of H. axyridis. Cluster size in H. axyridis was significantly larger than that in H. yedoensis; however, the total number of eggs and oviposition cost (by volume) per female in H. yedoensis were not significantly different from those in H. axyridis, although total number of clusters tended to be slightly higher in H. yedoensis than in H. axyridis. The percentage of undeveloped eggs per cluster in H. yedoensis was not significantly different from that in H. axyridis, whereas the percentage of developed eggs with delayed hatching per cluster was significantly larger in H. yedoensis than in H. axyridis. Moreover, the cost of sibling cannibalism per hatched larval cluster in H. yedoensis (worth 4.43 sibling eggs) was 3.36 times larger than that in H. axyridis.Therefore, maternal investment through egg and sibling cannibalism in developed eggs with delayed hatching are more intense in H. yedoensis than in H. axyridis, implying a higher larval survival rate through higher ability of prey capturing at the first instar. The results in this study suggest that the higher survival rate and accelerated development in H. yedoensis by the two maternal investments, i.e., a large egg and intense sibling cannibalism of developed eggs with delayed hatching, may play an important role in sympatric coexistence with the aggressive aphidophagous ladybird beetle H. axyridis. |
Bladder grasshoppers (Caelifera: Pneumoridae) contain three adipokinetic peptidesGerd GÄDEEur. J. Entomol. 105 (2): 211-217, 2008 | DOI: 10.14411/eje.2008.030 The corpora cardiaca (CC) of the pneumorid grasshopper species Bullacris discolor contain at least one substance that causes hyperlipaemia in the migratory locust. Isolation of neuropeptides belonging to the adipokinetic hormone (AKH) family was achieved by single-step reversed-phase high performance liquid chromatography (RP-HPLC) of CC extracts and monitoring tryptophan fluorescence. The material of the bladder grasshopper showed three distinct fluorescence peaks with adipokinetic activity in the migratory locust. The peptide sequences were identified by Edman degradation after the N-terminal pyroglutamate residue had been cleaved off enzymatically, and the exact peptide masses were determined by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Moreover, the assigned peptides were synthesised and natural and synthetic peptides were compared in their behaviour in RP-HPLC. B. discolor stores three AKH peptides in its CC: two of those are octapeptides, Schgr-AKH-II (pELNFSTGWamide) and Peram-CAH-II (pELTFTPNWamide), whereas the third peptide is a decapeptide, Phyle-CC (pELTFTPNWGSamide. The concentration of carbohydrates in the haemolymph of B. discolor is about 3 times higher than the lipid concentration. Upon injection with synthetic Schgr-AKH-II no adipokinetic or hypertrehalosaemic effect was measurable. A literature survey appears to indicate that an active role of these AKH peptides in substrate mobilisation is only overtly displayed in those caeliferan species that undertake well-defined flight periods. |



