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Review of Ceranisus (Hymenoptera: Eulophidae) of Turkey, with description of a new speciesMiktat DOĞANLAR, Serguei V. TRIAPITSYNEur. J. Entomol. 104 (1): 105-110, 2007 | DOI: 10.14411/eje.2007.016 Three species of Ceranisus Walker, 1841 (Hymenoptera: Eulophidae: Entedoninae) were collected recently in Turkey, including C. menes (Walker, 1839) and C. pacuvius (Walker, 1841) in southeastern Anatolia. A new species, C. hirsutus Doğanlar & S. Triapitsyn, is described from Şanliurfa Province. The genus Urfacus Doğanlar, 2003 is synonymized under Ceranisus and its type species, U. bozovaensis Doğanlar, 2003 is transferred to Ceranisus as C. bozovaensis (Doğanlar, 2003) comb. n., and the species is redescribed from the new material. An identification key to both sexes of Ceranisus from Turkey and Europe is provided. |
Spatial variation in the incidence of a sexually transmitted parasite of the ladybird beetle Adalia bipunctata (Coleoptera: Coccinellidae)K. Mary WEBBERLEY, Matthew C. TINSLEY, John J. SLOGGETT, Michael E.N. MAJERUS, Gregory D.D. HURSTEur. J. Entomol. 103 (4): 793-797, 2006 | DOI: 10.14411/eje.2006.108 Whilst sexually transmitted pathogens and parasites are common on insects and other animals, the factors affecting their incidence are currently uncertain. In order to understand the factors important in determining the presence of sexually transmitted parasites, it would be helpful to have information on intraspecific variation in incidence, as the causes of this variation are likely to reflect the likely causes of the presence/absence of sexually transmitted parasites across species. We therefore mapped the incidence of the parasite Coccipolipus hippodamiae within Europe on its primary host, the ladybird Adalia bipunctata. We observed that C. hippodamiae was present widely in Central, Southern and Eastern Europe, but was absent from northerly and north-western populations. The cause of this pattern of incidence variation is discussed, with particular reference to the voltinism of the host. We also note that the distribution of C. hippodamiae on A. bipunctata is not congruent with that of another sexually transmitted parasite of this species, Hesperomyces virescens. |
Determination of female-biased sexual size dimorphism in moths with a variable instar number: The role of additional instarsToomas ESPERK, Toomas TAMMARUEur. J. Entomol. 103 (3): 575-586, 2006 | DOI: 10.14411/eje.2006.078 While the ultimate causes and adaptive significance of sexual size dimorphism (SSD) have been extensively studied, the developmental mechanisms behind this phenomenon have received little attention. Going through an additional larval instar may form a specific way of achieving SSD in arthropods. In the present study, the mechanisms of SSD determination of two lymantriid moths, with marked SSD, were studied. In both species, females tended to go through an additional instar compared to males, and form pupae that were more than twice the weight of the males. To reveal the role of an extra instar, larval growth was monitored in the laboratory and the growth parameters were analysed as dependent on sex and developmental type (number of instars). Prolongation of growth by means of adding an additional larval instar in females turned out to be the key mechanism in the determination of the highly female-biased SSD in the species studied. There is thus a developmental mechanism available that permits achieving a larger size by means of extending the growth period. This provides evidence against constraint-based evolutionary explanations for body sizes in insects. There was no considerable accumulation of SSD during earlier larval life when females went through more instars than males. In contrast, in those cases in which males and females had the same number of instars, SSD accumulated gradually during the course of several larval instars. Longer growing period turned out to be a crucial mechanism leading to the female-biased SSD even when instar number did not differ between sexes, although higher instantaneous relative growth rates of females also played a complementary role in the latter case. Within sexes, an additional instar was characteristic of initially smaller larvae, as predicted by the "threshold size" hypothesis. |
Crustacean red pigment-concentrating hormone Panbo-RPCH affects lipid mobilization and walking activity in a flightless bug Pyrrhocoris apterus (Heteroptera) similarly to its own AKH-peptidesRadomír SOCHA, Dalibor KODRÍK, Rostislav ZEMEKEur. J. Entomol. 104 (4): 685-691, 2007 | DOI: 10.14411/eje.2007.086 In the present study we tested whether the walking activity of macropterous females of the flightless wing-polymorphic bug Pyrrhocoris apterus (L.) can be stimulated by its native adipokinetic hormone Peram-CAH-II and the crustacean red pigment-concentrating hormone (Panbo-RPCH), and the effectiveness of the latter hormone in a lipid mobilization assay. Two different doses (10 or 40 pmol) of Peram-CAH-II or Panbo-RCPH were injected into 10-day-old macropterous females of P. apterus to evaluate their effects on the walking activity of treated females. The results obtained showed a significant stimulation of walking activity only with the lower dose (10 pmol) of either hormone Peram-CAH-II or Panbo-RPCH. On the contrary, the walking activity of the same-aged females of macropterous morph treated with the higher dose (40 pmol) of these hormones was decreased. The energy substrates mobilized in Panbo-RPCH-treated macropterous females were lipids. The question of whether the stimulation of locomotion by Panbo-RPCH is limited only to P. apterus or if it might also represent an important function of this hormone in other insects or even in crustaceans is discussed. |
A new Middle Jurassic "grylloblattodean" family from China (Insecta: Juraperlidae fam. n.)Di-Ying HUANG, André NELEur. J. Entomol. 104 (4): 837-840, 2007 | DOI: 10.14411/eje.2007.104 The new family Juraperlidae is erected for the new genus and species Juraperla daohugouensis from the Chinese Middle Jurassic. Its wing venation has strong similarities with that of Mesozoic taxa currently included in the group "Grylloblattodea", but its character "three (or four?)-segmented tarsi" questions its potential inclusion into the same order with the modern Grylloblattodea. This suggests that the systematic assignments of several fossil "grylloblattid" species, mainly based on wing venation, could be very different. |
Redescription of a weevil Paramecops sinaitus (Coleoptera: Curculionidae: Molytinae) from the Sinai and an ecological study of its interaction with the Sinai milkweed Asclepias sinaica (Gentianales: Asclepiadaceae)Tim NEWBOLD, Massimo MEREGALLI, Enzo COLONNELLI, Maxwell BARCLAY, Shereen ELBANNA, Nancy ABU FANDUD, Frank FLEGG, Rasha FOUAD, Francis GILBERT, Vanessa HALL, Claire HANCOCK, Mona ISMAIL, Samr OSAMY, Isra'a SABER, Fayez SEMIDA, Samy ZALATEur. J. Entomol. 104 (3): 505-515, 2007 | DOI: 10.14411/eje.2007.071 We collected specimens of Paramecops sinaitus (Pic, 1930) (Curculionidae: Molytinae) from south Sinai in Egypt, which enabled us to make the first complete description of this species. We also include some taxonomic remarks on the genus. Paramecops solenostemmatis (Peyerimhoff, 1930) is a synonym of Paramecops sinaitus. We propose the new combination Paramecops sogdianus (Nasreddinov, 1978), based on Perihylobius sogdianus Nasreddinov, 1978, which would make Perihylobius and Paramecops synonymous. Like other Paramecops species, P. sinaitus appears to share a close interaction with Asclepiads, in this case the Sinai milkweed Asclepias sinaica (Boiss.) Muschl., 1912 (Asclepiadaceae). We investigated the oviposition behaviour of female weevils to test whether it is linked to larval performance, as predicted by coevolutionary theory. We found that female oviposition preference was positively related to plant size and to the volume of the seed follicles in which the eggs were laid. The survival of eggs was negatively related to plant size, perhaps due to plant differences in the production of defensive cardenolides. Larval survival was not related to plant size but increased with follicle volume, probably as a result of competition for food. Paramecops is relatively sedentary and nocturnal in its behaviour. Night-time observations of behaviour showed that weevils were more active at lower temperatures. |
Male genital variation in a moth Pammene luedersiana (Lepidoptera: Tortricidae)Marko MUTANEN, Seppo RYTKÖNEN, Jari LINDÉN, Janne SINKKONENEur. J. Entomol. 104 (2): 259-265, 2007 | DOI: 10.14411/eje.2007.040 Insect genital characters are extensively used in species level taxonomy, and their value in species delimitation is great. Based on the lock-and-key hypothesis and that genital differences function as a mechanical isolation system between species, the value of genital characters has been thought to be superior to non-genital characters. Although geographical and other kind of intraspecific variation of genitalia is often assumed very moderate, its real extent is insufficiently investigated. We examined patterns of morphological variation in the male genitalia of the tortricid moth Pammene luedersiana, using geometric morphometric tools including thin-plate spline deformation grids, and found significant variation. This variation is continuous both within and between populations. No systematic shape variation was observed between populations, but genital size showed some geographic variability. The results suggest that genital morphology is not constant and should therefore be used with caution in lepidopteran taxonomy. |
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. |
Winter climates and coldhardiness in terrestrial insectsWilliam J. TURNOCK, Paul G. FIELDSEur. J. Entomol. 102 (4): 561-576, 2005 Overwintering insects must avoid injury and death from the freezing of tissues and from metabolic disruptions associated with exposure to low, non-freezing temperatures. The winter climates of the world are classified in relation to insect overwintering on the basis of their minimum temperatures and the duration of the winter (when temperatures are below the thermal range for activity and development). Outside the Tropical Wet zone, the severity of exposure to cold (temperature, snowfall, duration of exposure, predictability, variability) can vary from a few days at 0°C to months below -20°C with extremes as low as -60°C. The severity of the temperature exposure may be ameliorated by the selection by insects of overwintering sites (exposed, partly-exposed, protected). The relationships among overwintering habitats, the minimum winter temperature in climatic zones, and the supercooling points (SCP) of over 350 terrestrial insects from published reports were examined. Variability in the SCP among insects within each climatic zone and habitat was wide. Among the freeze-susceptible species that overwintered in exposed or partly-protected habitats the SCP and the cold severity of climate were correlated. This was not the case for insects that overwintered in protected habitats. The SCP's of freeze-tolerant insects were generally higher than the freeze-susceptible insects, and the SCP's were not tightly linked with the cold severity of climatic zone. Insects, both freeze-susceptible and freeze-tolerant, overwintering in exposed habitats had lower SCP's than insects from habitats that offered some protection from ambient temperatures. Thirty-eight species had reports of SCP's for different geographical locations. Although there were occasionally differences in the SCP's, there was no consistent pattern of insects having lower SCP's when overwintering in colder habitats. The incidence of freeze-tolerance was higher in boreal and polar climatic zones than in climatic zones with warmer winters. Holometabola insects had a higher incidence of freeze-tolerance than hemimetabola insects. Suggestions for future research directions are outlined. |
The pollens consumed by common green lacewings Chrysoperla spp. (Neuroptera: Chrysopidae) in cabbage crop environment in western FranceJohanna VILLENAVE, Dominique THIERRY, Abdullah AL MAMUN, Thierry LODÉ, Elizabeth RAT-MORRISEur. J. Entomol. 102 (3): 547-552, 2005 | DOI: 10.14411/eje.2005.078 The pollens consumed by common green lacewings Chrysoperla spp. in crop environment in western France, were analysed. The diverticulum contents including quantity of pollen of Chrysoperla adults were analysed to compare a feeding behaviour between the sexes. Females consume more pollen than males. The feeding behaviour of the two main species present was compared, yielding new insights into differences between species within the complex Chrysoperla carnea (Stephens). |
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. |
Pre-adult development and longevity in natural populations of Lymantria dispar (Lepidoptera: Lymantriidae)Jelica LAZAREVIĆ, Vesna PERIĆ-MATARUGA, Nikola TUCIĆEur. J. Entomol. 104 (2): 211-216, 2007 | DOI: 10.14411/eje.2007.033 While most theoretical models for the evolution of ageing assume that duration of pre-adult development does not affect the longevity, experimental data are still controversial and inconsistent. Here we examined the short-term and long-term pattern of pre-adult development time and longevity in populations of the gypsy moth (Lymantria dispar) originating from either oak forest (Quercus petrea), a suitable, or locust-tree forest (Robinia psedoacacia), a poor habitat. Using a full-sib design, we examined the genetic correlations between traits found in larvae reared on oak or locust-tree leaves. We detected only negative and insignificant genetic correlations, except for males from the Robinia population reared on oak leaves where the correlation was negative and significant. Our results also showed that a population living 40 generations in the locust-tree forest exhibited a significantly higher longevity than the Quercus population, whereas a significant difference between these two populations in pre-adult development time does not exist. The results are discussed in relation to the potential effect of stress selection in moulding the longevity of the gypsy moth. |
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. |
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. |
Quantifying aphid predation rates of generalist predators in the fieldJames D. HARWOOD, John J. OBRYCKIEur. J. Entomol. 102 (3): 335-350, 2005 | DOI: 10.14411/eje.2005.051 The community of predators within agroecosystems has the potential to restrict aphid populations, especially early in the season before exponential increases in density and prior to the arrival of specialist natural enemies. Although direct observations of predation, laboratory feeding trials and manipulative field studies have been used to estimate levels of biological control exerted by different species (or potentially negative interactions between them), it is often difficult to extrapolate results to naturally occurring interactions in the field. |
Identity, larva and distribution of the Oriental soldier fly, Odontomyia ochropa (Diptera: Stratiomyidae)Jana NERUDOVÁ-HORSÁKOVÁ, Damir KOVAC, Rudolf ROZKO©NÝEur. J. Entomol. 104 (1): 111-118, 2007 | DOI: 10.14411/eje.2007.017
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Prevalence and association of the laboulbenialean fungus Hesperomyces virescens (Laboulbeniales: Laboulbeniaceae) on coccinellid hosts (Coleoptera: Coccinellidae) in Kentucky, USAJames D. HARWOOD, Carlo RICCI, Roberto ROMANI, Kevin M. PITZ, Alex WEIR, John J. OBRYCKIEur. J. Entomol. 103 (4): 799-804, 2006 | DOI: 10.14411/eje.2006.109 The laboulbenialean fungi occur throughout the world and are closely associated with a range of arthropods, including many coleopteran hosts. Throughout the summer of 2004, coccinellids were collected from a Bluegrass savanna woodland ecosystem, dominated by blue ash Fraxinus quadrangulata and Chinkapin Oak Quercus muehlenbergii, and the adults were examined for the presence of Hesperomyces virescens using binocular and scanning electron microscopy. Over 80% of adult Harmonia axyridis, a species previously reported as having a persistent association with the fungus, were infected. No significant differences were observed in incidence on male and female hosts, however, the distribution of fungus differed between sexes. Female H. axyridis had a greater percentage of infection on their elytron compared to other parts of their body whilst male infection was concentrated around their elytra, legs and abdomen. Although infection rates were significantly lower, we report, for the first time, the presence of this fungus on the hosts Cycloneda munda, Brachiacantha quadripunctata and Psyllobora vigintimaculata. This is the first study documenting the incidence of this insect-associated fungus with these native coccinellids of North America. In the samples collected from the Bluegrass savanna, two species (Coleomegilla maculata and Hyperaspis signata) were not infected by this fungus. |
Mitochondrial DNA provides an insight into the mechanisms driving diversification in the ithomiine butterfly Hyposcada anchiala (Lepidoptera: Nymphalidae: Ithomiinae)Alaine WHINNETT, Keith R. WILLMOTT, Andrew V.Z. BROWER, Fraser SIMPSON, Marie ZIMMERMANN, Gerardo LAMAS, James MALLETEur. J. Entomol. 102 (4): 633-639, 2005 Geographic subspecies of several ithomiine butterflies on the lower east Andean slopes display a black and orange "melanic tiger" aposematic wing pattern that occurs from Colombia to Bolivia, while geographically adjacent lowland subspecies typically bear a coloured, "tiger" pattern. However, it is not clear whether subspecies with similar wing patterns in different regions have arisen through independent events of convergent adaptation, possibly through parapatric differentiation, or result from allopatric differentiation, as proposed by the refuge hypothesis. Here, we examine geographic patterns of divergence in the widespread and common ithomiine butterfly Hyposcada anchiala. We present phylogenetic hypotheses for 5 subspecies of H. anchiala, based on 1567 bp mitochondrial DNA. All topologies indicated that a single switch in mimetic pattern best explained the wing patterning of the H. anchiala studied here. This finding suggests that the subspecies of H. anchiala studied here result from at least two stages of differentiation, and is consistent with a single colonisation into a novel altitudinal zone coincident with a wing pattern switch, followed by subsequent divergence within, rather than across altitudinal zones. The subspecies divergences indicated diversifications were consistent with the Pleistocene. Furthermore, the lowland subspecies were more recently derived than the montane taxa, in contrast to predictions of the "Andean species pump" hypothesis. |
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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New significant fossil insects from the Upper Carboniferous of Ningxia in northern China (Palaeodictyoptera, Archaeorthoptera)Jakub PROKOP, Dong RENEur. J. Entomol. 104 (2): 267-275, 2007 | DOI: 10.14411/eje.2007.041 New palaeodictyopterid Namuroningxia elegans sp. n. (Namuroningxiidae fam. n.) and archaeorthopterid Sinopteron huangheense gen. n., sp. n. (uncertain family assignment) are described from the Tupo Formation (Upper Carboniferous, Namurian, northern China, Ningxia Hui Autonomous Region). Both new taxa exhibit a unique structure of their wing venation pattern. The Namuroningxiidae fam. n. bears a mosaic of characters diagnostic of several "palaeopteran" families throughout Palaeodictyopteroida and Eupalaeoptera. This fact is highly interesting in reference to the Namurian age known for the occurrence of the first winged insects as well as the palaeogeographical position of the locality far from all sites in Laurussia. The preliminary study of entomofauna diversity exhibit frequent occurrence of archaeorthopterid wing fragments (e.g., Sinopteron huangheense) forming up to 40 percent of all insect specimens demonstrate high abundance of this group in the early Late Carboniferous ecosystems. |
Development of the entomopathogenic hyphomycete Lecanicillium muscarium (Hyphomycetes: Moniliales) on various hostsHassan ASKARY, Hamid YARMANDEur. J. Entomol. 104 (1): 67-72, 2007 | DOI: 10.14411/eje.2007.011 The present scanning electron microscopy study describes the development of Lecanicillium muscarium, strain DAOM 198499, on the surface of diverse hosts, including Sphaerotheca fuliginea, a fungal host, and Macrosiphum euphorbiae and Aphidius nigripes, insect hosts. The hosts were sprayed with a conidial suspension of L. muscarium (107 conidia/ml). The specimens used in the SEM investigation were collected at particular periods after spraying and prepared for scanning using standard methods. Germination tubes developed twenty-four hours after applying L. muscarium conidia to each host. Hyphae were attached to the host by a thin mucilaginous matrix. Seventy-two hours after spraying, hyphae of S. fuliginea had collapsed and were encircled by the parasite, and primary sporulation of L. muscarium was observed. On the aphid host, colonization started with adherence of the conidia to the host cuticle, followed by conidial germination and growth of mycelium on the surface of the insect's integument. After 48 to 72 h, post colonization, the first sporulation was observed on the cuticle, particularly at articulations. The mode of parasitism of A. nigripes by this fungus was similar to that of the aphid. Development of L. muscarium was observed on both mummified aphids (containing the pupae of parasitoids) and adult parasitoids. |
Diapause development and cold hardiness of Pectinophora gossypiella (Lepidoptera: Gelechiidae) larvae in GreeceOlga P. KALTSA, Panagiotis G. MILONAS, Matilda SAVOPOULOU-SOULTANIEur. J. Entomol. 103 (3): 541-545, 2006 | DOI: 10.14411/eje.2006.072 Larval diapause development and termination and some characteristics of cold hardiness in Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) were studied under field conditions in northern Greece. P. gossypiella overwintering larvae were sampled at 20 to 30 day intervals and subjected to two photoperiodic regimes at 20°C. In larvae kept under a long-day photoperiod (16L : 8D) diapause development was accelerated compared to those kept under a short-day photoperiod (8L : 16D). There was no difference in response to the two photoperiods after February. Mean number of days to pupation of P. gossypiella overwintering larvae decreased progressively through the sampling period, from November to April. Chilling is not a prerequisite but does accelerate diapause development. Supercooling points for P. gossypiella overwintering larvae ranged from -14 to -17°C with the majority dying after freezing. |
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. |
Sexual dimorphism and light/dark adaptation in the compound eyes of male and female Acentria ephemerella (Lepidoptera: Pyraloidea: Crambidae)Ting Fan (Stanley) LAU, Elisabeth Maria GROSS, Victor Benno MEYER-ROCHOWEur. J. Entomol. 104 (3): 459-470, 2007 | DOI: 10.14411/eje.2007.066 In the highly sexual-dimorphic nocturnal moth, Acentria ephemerella Denis & Schiffermüller 1775, the aquatic and wingless female possesses a refracting superposition eye, whose gross structural organization agrees with that of the fully-winged male. The possession of an extensive corneal nipple array, a wide clear-zone in combination with a voluminous rhabdom and a reflecting tracheal sheath are proof that the eyes of both sexes are adapted to function in a dimly lit environment. However, the ommatidium of the male eye has statistically significantly longer dioptric structures (i.e., crystalline cones) and light-perceiving elements (i.e., rhabdoms), as well as a much wider clear-zone than the female. Photomechanical changes upon light/dark adaptation in both male and female eyes result in screening pigment translocations that reduce or dilate ommatidial apertures, but because of the larger number of smaller facets of the male eye in combination with the structural differences of dioptric apparatus and retina (see above) the male eye would enjoy superior absolute visual sensitivity under dim conditions and a greater resolving power and ability to detect movement during the day. The arrangement of the microvilli in the rhabdom of both genders suggests that their eyes are polarization-sensitive, an ability they would share with many aquatic insects that have to recognize water surfaces. Although sexual recognition in A. ephemerella is thought to chiefly rely on pheromones, vision must still be important for both sexes, even if the females are wingless and never leave their watery habitat. Females swim actively under water and like their male counterparts, which fly above the surface of the water, they would have to see and avoid obstacles as well as potential predators. This, together with a small incidence of winged females, we believe, could be the reason why the eyes of female A. ephemerella are less regressed than those of other sexually dimorphic moths, like for instance Orgyia antiqua. Another, but difficult to test, possibility is that male and female A. ephemerella have diverged in their behaviour and habitat preferences less long ago than other sexually dimorphic moths. |
Eurytoma robusta (Hymenoptera: Eurytomidae), a local key factor in the population dynamics of Urophora cardui (Diptera: Tephritidae): a comparative analysisHelmut ZWÖLFER, Marc BÖHEIM, Erwin BECKEur. J. Entomol. 104 (2): 217-224, 2007 | DOI: 10.14411/eje.2007.034
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Factors terminating ovarian arrest in long-winged females of a flightless bug, Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)Radomír SOCHAEur. J. Entomol. 104 (1): 15-22, 2007 | DOI: 10.14411/eje.2007.003 The aim of the present study was to determine the factors that are involved in termination of a non-diapause type of ovarian arrest in the adult macropterous females of a flightless bug, Pyrrhocoris apterus (L.), reared under a long-day (18L : 6D) photoperiod. Application of an active analogue of juvenile hormone, methoprene, to adult macropterous females kept under the above conditions induced precocious termination of ovarian arrest and shortened the length of the pre-oviposition period. The results indicate that a temporary ovarian arrest in spontaneously fasting long-day macropterous females results from a deficiency of juvenile hormone. The length of the pre-oviposition period was shortened and ovarian arrest terminated also by de-alation, high temperature and by a prolonged period of starvation. Mating of long-day macropterous females with reproductively active males had no effect on the length of the pre-oviposition period. There was a relationship between the length of the starvation period and the post-feeding pre-oviposition period. The longer the starvation period, the shorter the period from when food was supplied to first oviposition. The results indicate that depletion of the fat body reserves resulting from prolonged fasting, followed by resumption of food intake are pre-requisites for full activation of the corpus allatum and egg development, and play a role in completion and termination of non-diapause ovarian arrest in long-day macropterous females. This phenomenon was never observed in short-day brachypterous females in reproductive diapause. |
Complex phenological responses to climate warming trends? Lessons from historyTim H. SPARKS, Kerstin HUBER, Roger L.H. DENNISEur. J. Entomol. 103 (2): 379-386, 2006 | DOI: 10.14411/eje.2006.051 Responsiveness of Lepidoptera phenology to climate has been detected in a number of species during the current trend in global warming. There is still a question of whether climate signals would be evident in historical data. In this paper we examine the climatic response of 155 species of moths and butterflies collected during the period 1866-1884 in Wiltshire, southern England. In general, species responded to increased temperature in the previous October by delayed appearance and to increased temperature in the current spring by advanced appearance. Thus, differential changes in temperatures of the autumn and spring could well affect changes in the relative pattern of the phenology of species. Attributes influencing the species' ecology were examined to see if they influenced temperature responsiveness. In general, few consistent effects emerged, though responsiveness to climate was found to be greater for species eclosing later in the year, specifically to the previous autumn temperatures, and to hibernal environment, increasingly for species less exposed to air temperatures. These findings warn against expecting simple responses to climate warming. |
Number of larval instars and sex-specific plasticity in the development of the small heath butterfly, Coenonympha pamphilus (Lepidoptera: Nymphalidae)Enrique GARCÍA-BARROSEur. J. Entomol. 103 (1): 47-53, 2006 | DOI: 10.14411/eje.2006.007 The number of larval moults, larval head capsule width and pupal weight were investigated in both direct-developing and diapausing individuals of a South-West European population of Coenonympha pamphilus. The frequency distributions of head widths of successive larval instars overlapped, partly due to variation in the number of larval moults. The larvae that entered diapause went through five instars, instead of the four reported from this species. The evidence indicates that the five instar developmental pathway represents a plastic response rather than an example of compensatory growth. This alternative growth pattern was expressed in response to short photoperiods in parallel with, or as a consequence of, larval diapause. On average, the larvae with five instars had larger heads than their normal siblings. This resulted in comparatively heavier male pupae, while the opposite trend occurred in females. It is concluded that the variation in the number of larval instars is a plastic response to diapause when temperatures remain mild and that it might have an adaptive value in areas with mild winter climates. The sexually dimorphic expression in the larval growth patterns, in terms of pupal weight, may well imply different patterns of allocation of larval resources to adult structures, although sex-dependent differences in investment into purely larval structures cannot be discounted. |
A gut-specific chitinase from the mulberry longicorn beetle, Apriona germari (Coleoptera: Cerambycidae): cDNA cloning, gene structure, expression and enzymatic activityYoung Moo CHOO, Kwang Sik LEE, Bo Yeon KIM, Doh Hoon KIM, Hyung Joo YOON, Hung Dae SOHN, Byung Rae JINEur. J. Entomol. 104 (2): 173-180, 2007 | DOI: 10.14411/eje.2007.026 A gut-specific chitinase gene was cloned from the mulberry longicorn beetle, Apriona germari. The A. germari chitinase (AgChi) gene spans 2894 bp and consists of five introns and six exons coding for 390 amino acid residues. AgChi possesses the chitinase family 18 active site signature and three N-glycosylation sites. Southern blot analysis of genomic DNA suggests that AgChi is a single copy gene. The AgChi cDNA was expressed as a 46-kDa polypeptide in baculovirus-infected insect Sf9 cells and the recombinant AgChi showed activity in a chitinase enzyme assay. Treatment of recombinant virus-infected Sf9 cells with tunicamycin, a specific inhibitor of N-linked glycosylation, revealed that AgChi is N-glycosylated, but the carbohydrate moieties are not essential for chitinolytic activity. Northern and Western blot analyses showed that AgChi was specifically expressed in the gut; AgChi was expressed in three gut regions, indicating that the gut is the prime site for AgChi synthesis in A. germari larvae. |
Period of adult activity and response to wood moisture content as major segregating factors in the coexistence of two conifer longhorn beetles, Callidiellum rufipenne and Semanotus bifasciatus (Coleoptera: Cerambycidae)Ryûtarô IWATA, Takahisa MARO, Yasushi YONEZAWA, Tôru YAHAGI, Yoshirô FUJIKAWAEur. J. Entomol. 104 (2): 341-345, 2007 | DOI: 10.14411/eje.2007.049 The cerambycid borers Callidiellum rufipenne (Motschulsky) and Semanotus bifasciatus (Motschulsky) infest coniferous logs in Japan, with the latter distributed in the north and at high altitudes, where both species occur sympatrically. Semanotus bifasciatus adults were active at low temperatures and very active after sunset, and less active but never inactive in the daytime, whereas C. rufipenne adults were usually active at high temperatures and almost only in the daytime. At an almost constant temperature, C. rufipenne adults were almost inactive at night, whereas S. bifasciatus adults showed only an obscure decline in activity in the morning. Of a horizontal log, the upper surface tended to be drier and lower surface wetter, and C. rufipenne larvae grew large if they were in the upper part of a log, whereas S. bifasciatus larvae grew large if in the lower part. Thus, the coexistence of these two species can be ascribed to two major segregation factors: adult segregation based on temperature and sunshine, and larval segregation associated with the moisture content of the wood. |



