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Results 1231 to 1260 of 2340:

Comparative study of larvae of Tenebrionoidea (Coleoptera: Cucujiformia)

Rolf Georg BEUTEL, Frank FRIEDRICH

Eur. J. Entomol. 102 (2): 241-264, 2005 | DOI: 10.14411/eje.2005.037

External and internal head structures and external structures of the thorax and abdomen of larval representatives of Melandryidae (Orchesia), Ulodidae (Meryx), Oedemeridae (Pseudolycus) and Pythidae (Pytho) are described. The obtained data were compared to characters of other tenebrionoid larvae and to larval characters of other representatives of Cucujiformia. Characters potentially relevant for phylogenetic reconstruction are listed and were analysed cladistically. The data set is characterised by a high degree of homoplasy and the resolution of the strict consensus trees of 2650 or 815 (second analysis) minimal length trees is low. The monophyly of Tenebrionoidea is supported by several larval autapomorphies, e.g. posteriorly diverging gula, anteriorly shifted posterior tentorial arms, asymmetric mandibles and the origin of several bundles of M. tentoriopharyngalis from the well-developed gular ridges. Several features of the larval head are plesiomorphic compared to the cleroid-cucujoid lineage. The interrelationships of most tenebrionoid families not belonging to the pythid-salpingid and anthicid-scraptiid groups were not resolved. Synchroidae were placed as sister group of a clade comprising these two lineages and Prostomidae. A sistergroup relationship between Trictenotomidae and Pythidae seems to be well supported and the monophyly of the anthicid-scraptiid lineage was also confirmed. Another potential clade comprises Prostomidae, Mycteridae and Boridae, and possibly Pyrochroidae (s.str.) and Inopeplinae. The monophyly of Salpingidae (incl. Othniinae and Inopelinae) and Pyrochroidae (incl. Pedilinae) was not supported. Many features such as the shape of the head and body, sutures and ridges of the head capsule, the endocarina, the mandibles, the maxillary apex, and also characters of the terminal abdominal apex are highly variable, even within families. Especially the families Tetratomidae, Melandryidae, Colydiidae and Zopheridae show a high degree of variation in the larval stages. Several taxa appear isolated in terms of larval morphology within the families they are assigned to, e.g. Orchesia within Melandryidae, Sphindocis (Sphindocinae) within Ciidae, Calopus (Calopinae) within Oedemeridae and Penthe (Penthinae) within Tetratomidae. A broader spectrum of characters and a stepwise approach will be needed for a reliable clarification of the relationships within a very complex group like Tenebrionoidea.

Insects on decomposing carcasses of small rodents in a secondary forest in Southeastern Brazil

Thiago De Carvalho MORETTI, Odair Benedito RIBEIRO, Patrícia Jacqueline THYSSEN, Daniel Russ SOLIS

Eur. J. Entomol. 105 (4): 691-696, 2008

The decomposition of small carcasses in the open is frequently neglected although it may provide information of forensic importance. This paper describes an experimental study of arthropod species associated with carcasses of mouse, Mus musculus (Linnaeus, 1758) and rat, Rattus norvegicus (Berkenhout, 1769) (Rodentia: Muridae). Four carcasses were left inside iron cages in sunlit and shady areas in a secondary forest in Southeastern Brazil twice a season for four seasons (n = 16 carcasses of each rodent). The carcasses were removed when arthropods ceased to visit them. The visiting and colonizing invertebrates were collected daily and identified. Immatures were also collected and reared in a laboratory for identification. We collected 6,514 arthropods (820 adults and 5,694 juvenile forms) belonging to 53 species from the families Sarcophagidae, Calliphoridae, Muscidae, Fanniidae, Syrphidae, Richardiidae, Sepsidae, Micropezidae, Otitidae, Drosophilidae, Phoridae, Dolichopodidae, Anthomyiidae, Asilidae and Lauxaniidae (Diptera), Formicidae, Ichneumonidae, Encyrtidae and Apidae (Hymenoptera), Staphylinidae (Coleoptera) and Gonyleptidae (Opiliones). Lucilia eximia (Wiedemann, 1819) (Diptera: Calliphoridae) and Peckia (Pattonella) intermutans (Walker, 1861) (Diptera: Sarcophagidae) deserve special attention because both adult and immature forms were collected in all seasons and in both areas. Our results indicate that the frequency of occurrence of these arthropods was positively associated with carcass size (mouse or rat); no marked insect succession on the carcasses occurred; and the diversity of Calliphoridae and Sarcophagidae was high, irrespective of season.

Leucopis annulipes larvae (Diptera: Chamaemyiidae) use a furtive predation strategy within aphid colonies

Bruno FRÉCHETTE, François LAROUCHE, Éric LUCAS

Eur. J. Entomol. 105 (3): 399-403, 2008 | DOI: 10.14411/eje.2008.050

A laboratory experiment was conducted to determine whether the predation strategy of larvae of the aphidophagous silver fly Leucopis annulipes Zetterstedt (Diptera: Chamaemyiidae) is furtive, as are larvae of the aphidophagous midge Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae), or active like aphidophagous ladybird beetle larvae (Coleoptera: Coccinellidae). The impact of L. annulipes larvae on pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), colony disturbance was evaluated and compared with that of the furtive predator A. aphidimyza and the active-searching ladybird beetle Harmonia axyridis Pallas. Results indicate that aphids showed significantly fewer defensive acts (dropping, walking away, wriggling) in the presence of L. annulipes larvae than of ladybird beetle larvae. Furthermore, the impact of L. annulipes larvae on aphid colony disturbance was similar to that of A. aphidimyza and to a control treatment without predators. These results clearly indicate that L. annulipes larvae use a furtive predation strategy.

Cold tolerance and trehalose accumulation in overwintering larvae of the codling moth, Cydia pomonella (Lepidoptera: Tortricidae)

Abbas KHANI, Saeid MOHARRAMIPOUR, Mohsen BARZEGAR

Eur. J. Entomol. 104 (3): 385-392, 2007 | DOI: 10.14411/eje.2007.057

Seasonal variations in the supercooling point, survival at low temperatures and sugar content were studied in field-collected codling moth larvae. The supercooling point of field-collected larvae decreased significantly from a mean value of -13.4°C in August 2004 (feeding larvae) to -22.0°C in December 2004 (overwintering larvae). Survival at -20°C/24 h was 0% during early autumn, whereas it increased to approximately 60% during winter. The survival at low temperature was well correlated with the supercooling point. The supercooling point of the diapause destined larvae decreased from -16.9 to -19.7°C between September and October as the larvae left the food source and spun a cocoon. For early-diapause larvae, exposure to 5°C/30 days has an additional effect and decreased the supercooling point from -19.7 to -21.3°C. One-month exposure of overwintering larvae to 5°C led to a mortality of 23% in early diapause larvae, while only 4% of diapause larvae died after acclimation. Overwintering larvae accumulated trehalose during winter. There was approximately a threefold increase in trehalose content between larvae at the onset of diapause (5.1 mg/g fresh weight) and larvae in a fully developed diapause (18.4 mg/g fresh weight) collected in January. Trehalose content was correlated with supercooling capacity, survival at low temperatures and chilling tolerance, suggesting that trehalose may play some role in the development of cold tolerance in this species.

Eurytoma robusta (Hymenoptera: Eurytomidae), a local key factor in the population dynamics of Urophora cardui (Diptera: Tephritidae): a comparative analysis

Helmut ZWÖLFER, Marc BÖHEIM, Erwin BECK

Eur. J. Entomol. 104 (2): 217-224, 2007 | DOI: 10.14411/eje.2007.034


Eurytoma robusta
Mayr (Chalcidoidea) exploits host galls either as a primary or secondary parasitoid, an entomophytophagous inquiline or occasionally even as a predator. We present data on its ecology and impact on gall densities and population trends of the gall fly Urophora cardui (L.) on Cirsium arvense (L.) Scop. Habitat preference, host gall selection, clutch size, and high incidence of superparasitism causing empty gall cells show that E. robusta, a generalist with a broad host spectrum, is relatively poorly adapted to parasitising U. cardui. The influence of E. robusta on U. cardui in the Belfort-Sundgau region (1970-2004), in the Upper Rhine Valley (1973-2004) and in north-eastern Bavaria (1977-2004), differed considerably. In the forests of the Upper Rhine Valley and the Belfort-Sundgau region, where U. cardui has relatively stable source-sink populations, E. robusta is present but not the dominant mortality factor of the gall fly. In most areas of north-eastern Bavaria U. cardui occurs in fragmented populations and short lived non-equilibrium metapopulations. In these systems E. robusta became more abundant over the last five years, which resulted in a high incidence of superparasitism, an increase in the number of empty gall cells and reduced gall quality. The greatly increased degree of parasitism and an excess of empty cells resulted recently in the collapse of most local populations of U. cardui in the study area south of Bayreuth (north-eastern Bavaria). Together with earlier records the data presented here suggest that in north-eastern Bavaria E. robusta cause fluctuations in the abundance of U. cardui, which have a periodicity of 5-7 years. A remarkable feature of the oligophagous E. robusta is its high fidelity to formerly abundant U. cardui populations, which, with declining host densities, leads to overexploitation, resulting in a high incidence of superparasitism and high larval mortality. The possible influence of the habitat structure on the effect of E. robusta on the population dynamics of U. cardui is discussed. Our data plus that of other authors suggest that, with regard to U. cardui, E. robusta can develop a temporary local host specialisation.

Bladder grasshoppers (Caelifera: Pneumoridae) contain three adipokinetic peptides

Gerd GÄDE

Eur. 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.

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 TÓTH

Eur. 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.

The Cixiidae (Hemiptera: Fulgoromorpha) of the Mascarenes islands and Madagascar. Endemism and description of new taxa from Réunion with notes on their host plants

Marc ATTIÉ, Thierry BOURGOIN, Jacques BONFILS

Eur. J. Entomol. 99 (4): 543-555, 2002 | DOI: 10.14411/eje.2002.071

Two new species (Hemiptera, Fulgoromorpha, Cixiidae) included in a new genus, Meenocixius gen. n., and associated with Acanthophœnix rubra (Bory) H. Wendl. (Arecaceae) are described from the island of La Réunion: M. bebourensis sp. n. and M. virescens sp. n. This genus shows several autapomorphies in its tegmina venation, very particular within the Fulgoromorpha. Borbonomyndus gen. n., is proposed for another new species, B. pandanicola sp. n. associated with Pandanus purpurascens Thouars (Pandanaceae), and B. pallidus (Synave), previously described as a member of the genus Eumyndus Synave. According to morphological and ethological data, E. bistriatus is synonymized with B. pallidus, of which three different forms are recognized. All species of Borbonomyndus are found associated with Pandanus. These two new genera are endemic to La Réunion. Without taxonomic standing, the subspecies of Brixia belouvensis are synonymyzed and restricted to four different forms. A key is proposed for the Cixiidae of La Réunion, which now includes 12 species belonging to 6 different genera: Achaemenes, Aselgeoides, Brixia, Oliarus (but we show that the species placed in this genus need to be reviewed), Borbonomyndus, and Meenocixius. Monophyly of Eumyndus, from which E. perinetensis Synave is excluded, is substantiated. Following the new interpretation, this genus is now restricted to Madagascar. The species Cubana insularis Muir, from the island of Rodrigues, is transferred to a new genus: Achaebana gen. n. Finally, cixiid endemism and their host-plant associations in the Mascarenes are discussed.

Latitudinal variation in morphology in two sympatric damselfly species with contrasting range dynamics (Odonata: Coenagrionidae)

Christopher HASSALL, David J. THOMPSON, Ian F. HARVEY

Eur. 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.

Effect of larval crowding on the life history traits of Sesamia nonagrioides (Lepidoptera: Noctuidae)

Argyro A. FANTINOU, Dionyssios C. PERDIKIS, Nikolaos STAMOGIANNIS

Eur. 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.

Flight muscle breakdown in the green-veined white butterfly, Pieris napi (Lepidoptera: Pieridae)

Fredrik STJERNHOLM, Bengt KARLSSON

Eur. J. Entomol. 105 (1): 87-91, 2008 | DOI: 10.14411/eje.2008.012

Flight is important for insects but also incurs costs in terms of reduced reproductive reserves. Recent studies on butterflies have shown that thorax mass and nitrogen content decrease over the adult lifespan, suggesting that flight muscle breakdown may also occur in butterflies. However, unlike other insects known to resorb flight muscles, butterflies will continue to fly throughout the reproductive period. Nonetheless, use of nutrients from flight muscles for reproduction has the potential to improve the reproductive output considerably. In this study we have tested to what extent female Pieris napi L. (Pieridae) butterflies actually do breakdown flight muscles. By comparing muscle mass in recently emerged and older free-flying females we show that mass and nitrogen content of the two most important groups of flight muscles each decrease by more than 50% over the adult lifespan. The significance of this finding is discussed in relation to reproduction and flight in butterflies.

Spermathecal morphology and sperm dynamics in the female Schizocosa malitiosa (Araneae: Lycosidae)

Gonzalo USETA, Bernhard A. HUBER, Fernando G. COSTA

Eur. 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.

Differences in the development of the closely related myrmecophilous butterflies Maculinea alcon and M. rebeli (Lepidoptera: Lycaenidae)

Marcin SIELEZNIEW, Anna M. STANKIEWICZ

Eur. J. Entomol. 104 (3): 433-444, 2007 | DOI: 10.14411/eje.2007.063

The initially phytophagous caterpillars of Maculinea alcon and M. rebeli complete their development in Myrmica ant colonies as social parasites. Recent genetic studies show no differences at the species level among various populations of each butterfly taxa. Usually M. alcon and M. rebeli are identified by habitat and larval food plants (Gentianaceae) and host ant specificity is also considered to be an important feature. However most of the ecological characteristics overlap at least in some parts of their distributions. The developmental and survival characteristics of caterpillars reared by different Myrmica species were compared in laboratory experiments and in the field. Morphologically indistinguishable M. alcon and M. rebeli, which originated from Polish populations, are very similar in terms of host specificity i.e. larvae survived both with M. scabrinodis and M. sabuleti. However they showed different growth characteristics. The earlier flight period of M. rebeli, which is synchronized with the phenology of Gentiana cruciata, resulted from the quick growth of caterpillars in Myrmica nests in the pre-winter phase, when they gained about half of their final body biomass. After the end of winter they recommenced growth almost immediately. M. alcon larvae entered diapause shortly after adoption by ants and began to increase in weight significantly just one month after the onset of spring, which synchronized their development with that of their larval food plant, G. pneumonanthe. Therefore neither population group is transferable between habitats and should still be regarded, at least, as distinct conservational units.

Male genital variation in a moth Pammene luedersiana (Lepidoptera: Tortricidae)

Marko MUTANEN, Seppo RYTKÖNEN, Jari LINDÉN, Janne SINKKONEN

Eur. 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.

Western flower thrips (Thysanoptera: Thripidae) preference for thrips-damaged leaves over fresh leaves enables uptake of symbiotic gut bacteria

Egbert J. DE VRIES, Rutger A. VOS, Gerrit JACOBS, Hans A.J. BREEUWER

Eur. J. Entomol. 103 (4): 779-786, 2006 | DOI: 10.14411/eje.2006.106

To understand the evolution of insect gut symbionts it is important to determine how they are passed on to the next generation. We studied this process in Erwinia species bacteria that inhabit the gut of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). This is a polyphagous herbivore and a world-wide pest in agricultural crops. With bacteria in the gut, the thrips larval development time can be shorter and its oviposition rate higher compared to bacteria-free thrips. Bacteria are not directly transmitted from mother to offspring, but larvae acquire bacteria from the leaves right after they hatch. These gut bacteria are present on the leaves on feeding sites used by other thrips before the larvae arrive, probably because these other thrips have deposited bacteria via faeces or regurgitation. In this study we addressed the question whether the transmission route of symbiotic bacteria influences the thrips feeding behaviour, and determined the feeding and oviposition preference of thrips, by giving them a choice between leaves with and leaves without prior grazing by other western flower thrips. This was studied for thrips with and thrips without gut bacteria. Young larvae prefer to feed on leaves that where grazed before by other thrips and females prefer to oviposit on these grazed leaves. These results are in contradiction to earlier studies that have found that thrips larvae fitness is lower on thrips damaged plants than on clean plants. This behaviour does however promote the establishment of gut bacteria in the thrips. The factors determining the preference for thrips-damaged leaves may be the physical leaf damage or odours that are produced by the plant, the bacteria or both.

Taxonomy of the genera Scaeva, Simosyrphus and Ischiodon (Diptera: Syrphidae): Descriptions of immature stages and status of taxa

Pavel LÁSKA, Celeste PÉREZ-BAÑÓN, Libor MAZÁNEK, Santos ROJO, Gunilla STÅHLS, M. Angeles MARCOS-GARCÍA, Vítězslav BIČÍK, Jindra DU©EK

Eur. J. Entomol. 103 (3): 637-655, 2006 | DOI: 10.14411/eje.2006.085

A review of all known descriptions of immature stages of the species of the genera Scaeva Fabricius, 1805, Ischiodon Sack, 1913 and Simosyrphus Bigot, 1882 is presented using SEM illustrations. The third instar larval and/or pupal morphology of Scaeva dignota (Rondani, 1857), Scaeva mecogramma (Bigot, 1860) and Simosyrphus grandicornis (Macquart, 1842) are newly described. All species of the genera studied in this paper are very similar for all the studied characters of their immature stages, including the chaetotaxy. Molecular characters of the mitochondrial cox1 gene (1128bp) were used for inferring relationships of the studied taxa. The nuclear internal transcribed spacer 2 (ITS2) was additionally applied for species delimitation of the closely related species Scaeva selenitica and S. dignota. The Palaearctic Scaeva species could be split into two groups based on the analysis of morphology of posterior respiratory process. These groups were previously diagnosed as S. selenitica-group [i.e., S. selenitica (Meigen, 1822), S. dignota (Rondani, 1857), S. mecogramma (Bigot, 1860)] and S. pyrastri-group [i.e., S. pyrastri (Linnaeus, 1758), S. albomaculata (Macquart, 1842), S. latimaculata (Brunetti, 1923)]. Semiscaeva Kuznetzov, 1985 and Scaeva Fabricius, 1805 are the available names for these two natural groups that should be classified as subgenera; the former name is proposed for S. selenitica-group and the latter for S. pyrastri-group. Mecoscaeva Kuznetzov, 1985 syn. n. is transferred as a junior synonym of the subgenus Semiscaeva Kuznetzov, 1985 according to the principle of the first reviser. Based on the analysis of immature stages, the generic name Ischiodon Sack, 1913 syn. n. is proposed as a junior synonym of the genus Simosyrphus Bigot, 1882. The similarity of immature stages between Scaeva s. str. and Simosyrphus grandicornis Macquart, 1842, Simosyrphus aegyptius (Wiedemann, 1830) comb. n. and Simosyrphus scutellaris (Fabricius, 1805) comb. n. is discussed. All the proposed subgeneric and generic taxa based on morphological studies received high support employing molecular characters.

Corn leaf aphid, Rhopalosiphum maidis (Hemiptera: Aphididae), is a key to greenbug, Schizaphis graminum (Hemiptera: Aphididae), biological control in grain sorghum, Sorghum bicolor

Gerald J. MICHELS, James H. MATIS

Eur. J. Entomol. 105 (3): 513-520, 2008 | DOI: 10.14411/eje.2008.068

In the sorghum/aphid/ladybeetle ecosystem found in the Texas High Plains Region of the United States, we found that the corn leaf aphid, Rhopalosiphum maidis (Fitch), is a key aphid species that provides a critical early-season food source for native coccinellids. From 1988 to 2000 data on the seasonal abundance of sorghum-infesting aphids and ladybeetles were collected from a total of 21 irrigated and 12 rain-fed grain sorghum fields. The data indicated that successful biological control of the greenbug by coccinellids is normally dependent on early-season colonization of the sorghum field by corn leaf aphids. When corn leaf aphids exceeded 100/plant before sorghum boot stage greenbugs never exceeded 125 aphids/plant. In all cases where greenbugs were found in densities that would cause economic damage to sorghum (>250/plant), corn leaf aphids reached a density of 100 or more per plant after sorghum reached the boot stage. In irrigated fields, the first record of coccinellid eggs and peak coccinellid abundance were positively and significantly (p = 0.05) correlated to the day of the year when corn leaf aphids reached or exceeded a minimum of 100/plant and corn leaf aphid peak abundance in both irrigated and rainfed fields. On the other hand, greenbug peak abundance was significantly correlated only to coccinellid peak abundance in irrigated fields. Regression analyses indicated that in paired analyses of irrigated and rain-fed sorghum fields, an increase of one aphid at time t, resulted in an increase in coccinellid peak abundance from 0.024 to 0.025 per 15 m of row at time t + 2 depending on aphid species, if corn leaf aphids reached a level of 100 or more per plant by sorghum boot stage and irrigation parameters. We concluded that corn leaf aphids are an important early-season food source for predaceous coccinellids, drawing these predators into the fields where they feed on the aphids and deposit eggs, engendering a captive larval population that is present when greenbug first begin to enter the field later in the season.

Chromosome number, karyotype morphology, heterochromatin distribution and nuclear DNA content of some talitroidean amphipods (Crustacea: Gammaridea)

Angelo LIBERTINI, Renata TRISOLINI, Massimiliano RAMPIN

Eur. J. Entomol. 105 (1): 53-58, 2008 | DOI: 10.14411/eje.2008.007

Chromosome number, karyotype formula, C-banding pattern, genome size and DNA base composition were studied in three species of Hyalidae and seven species of Talitridae. A karyotype of 25 chromosome pairs, with median centromeres (FN = 100), was found in all the species of Talitridae analysed and Apohyale prevostii. Genome size (C-value) varies among Talitrida from 0.94 pg in Apohyale crassipes to 2.81 pg in Orchestia gammarellus, and the percentage of AT-DNA in the whole genome ranges from 56.12% in A. crassipes to 68.17% in Sardorchestia pelecaniformis. In comparison with Hyalidae, Talitridae show more uniformity in chromosome number and karyotype formula, and have larger genomes. There is a direct correlation between total DNA content and the amount of C-heterochromatic DNA. The cytogenetical data on Talitrida were compared from a phylogenetic and an evolutional point of view. The increase in genome size during the evolution of the Talitrida possibly had a role in their adaptation to supralittoral life and extreme subaerial conditions.

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. MARSHALL

Eur. 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.

Effect of photoperiod on parasitization by Trichogramma principium (Hymenoptera: Trichogrammatidae)

Sergey Ya. REZNIK, Nina P. VAGHINA

Eur. J. Entomol. 104 (4): 705-713, 2007 | DOI: 10.14411/eje.2007.089

The effect of photoperiod on parasitization of the eggs of the Angoumois grain moth, Sitotroga cerealella (Olivier, 1789) by Trichogramma principium Sugonyaev & Sorokina, 1976 was investigated under several photoperiodic regimes of L : D = 3 : 21, 6 : 18, 9 : 15, 12 : 12, 15 : 9, 18 : 6 and 21 : 3. In all regimes, certain wasps delayed ovipositing in this non-preferred host. Potential fecundity of T. principium females (the number of mature ovarial eggs at emergence) and subsequent oogenesis (estimated by the number of mature ovarial eggs in non-ovipositing females) was independent of photoperiod. However, the percentage of females that oviposited was higher for females that developed and were kept under 6-12 h long photophase than for those that developed and were kept under ultra short (3L : 21D) and under long (18L : 6D and 21L : 3D) photophases. The average duration of the pre-oviposition (egg retention) period showed the opposite pattern to the photoperiodic response. A possible explanation of this reaction is that the delay in oviposition is adaptive if the probability of finding a better host is high. In autumn, when the last Trichogramma females are still active but their lepidopteran hosts are already much less abundant, then parasitization of any suitable host is the best strategy.

Tackling the "Protoblattoidea problem": Revision of Protoblattinopsis stubblefieldi (Dictyoptera; Late Carboniferous)

Olivier BÉTHOUX, Klaus-Dieter KLASS, Jörg W. SCHNEIDER

Eur. J. Entomol. 106 (1): 145-152, 2009 | DOI: 10.14411/eje.2009.017

The forewing morphology of the fossil species †Protoblattinopsis stubblefieldi Laurentiaux, 1953 (Dictyoptera; Late Carboniferous) is re-investigated. Unlike previously stated, in this species, the stems of R and M are distinct and CuA has branches. The occurrence of the putative plesiomorphies "long ScP" and "differentiated R sectors" (i.e., RA and RP) in †P. stubblefieldi indicates a position basal to all extant Dictyoptera and many members of its paraphyletic stem. Unlike representatives of the families †Archimylacridae and †Blattinopsidae, but similar to Blattodea s. str., †P. stubblefieldi lacks a M-CuA arculus. The comparison of the branching pattern of the median system in †P. stubblefieldi and †Archimylacridae suggests that the arculus of the latter is composed of posterior branches of M. It is noted that the distal location of the point of origin of CuA and CuP, the sigmoid course of the anterior stem of CuA, the strong curvature of CuP, and the occurrence of a short fusion between R/RP and the anterior branch of M are similarities with the representatives of the genus Polyphaga Brullé, 1835, belonging to Dictyoptera s. str. However, these similar character states are unlikely to be homologous in these taxa, mainly because the hypothesis that Polyphaga is the sister group of the remaining Dictyoptera s. str. (or even Blattodea s. str.) is not strongly supported. Owing to its character state combination, the species †P. stubblefieldi is unique within the "Protoblattoidea waste-basket". Comprehensive studies of wing morphology in stem-Dictyoptera are needed to clarify whether it might be closely related to the lineage from which Dictyoptera s. str. evolved.

Microsatellites for the highly invasive Cameraria ohridella (Lepidoptera: Gracillariidae) and their amplification in related species

Neus MARI MENA, Romain VALADE, Emmanuelle MAGNOUX, Sylvie AUGUSTIN, Carlos LOPEZ-VAAMONDE

Eur. 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.

Wing morph- and age-related differences in fertilization success of adult males of a flightless bug, Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

Radomír SOCHA

Eur. J. Entomol. 105 (1): 93-98, 2008 | DOI: 10.14411/eje.2008.013

The aim of the present study was to test the hypothesis that short-winged (brachypterous) and long-winged (macropterous) adult males of a flightless bug Pyrrhocoris apterus differ in fertilization success. For this purpose, 5, 10 and 28 days old brachypterous and macropterous males were mated for the same period of time with reproductively active 5 days old brachypterous females. The average hatchability of five egg batches of these females was used as a measure of the fertilization success of the males. The results revealed significantly higher hatchability of the eggs laid by females that copulated with 5 or 10 days old brachypterous males than with same-aged macropterous males. In contrast, the average hatchability of eggs of females that copulated with 28 days old brachypterous males was significantly lower than of those mated with same-aged macropterous males. It is the first report of wing morph- and age-related differences in fertilization success of males in insects with a non-functional wing-polymorphism. The possible relationship between wing- and age-related differential fertilization and the mating success of P. apterus males, and differences in the amount of secretion transferred from their accessory glands into the reproductive tract of females during copulation, is discussed.

Flightless Hawaiian Hemerobiidae (Neuroptera): Comparative morphology and biology of a brachypterous species, its macropterous relative and intermediate forms

Catherine A. TAUBER, Maurice J. TAUBER, Jon G. GIFFIN

Eur. J. Entomol. 104 (4): 787-800, 2007 | DOI: 10.14411/eje.2007.100

Five flightless species of Micromus are known from the Hawaiian Archipelago; only one, the rare Micromus usingeri, is reported from the Island of Hawai'i. Herein, we report the natural occurrence of intermediates between this brachypterous species and its near relative, the macropterous Micromus longispinosus. We compare some morphological and life-history characteristics of the two species and the intermediates. Our study shows that: (1) The two closely related species are broadly distributed on Hawai'i, but they appear to be allopatric altitudinally. (2) M. usingeri is associated with a cool, misty, high-altitude environment, M. longispinosus with warmer, rainy conditions at lower elevations. The intermediates occur in both types of situations and generally at intermediate elevations. (3) The macropterous M. longispinosus has large, oblong, flexible, membranous forewings and hind wings. In contrast, the brachypterous M. usingeri has convex, shortened, elytra-like forewings with reticulate venation, and very small, thick, triangular, stub-like hind wings with greatly reduced venation. The wings of intermediate specimens exhibit a broad range of variation between the two species. (4) Several characteristics of wing venation are highly correlated with reduced wing size; others are not. (5) Aside from the wings, adults of M. usingeri and M. longispinosus differ in relatively few morphological features, most notably the antennal and metatibial length, prothoracic length, mesothoracic length and width, and the length of the spine-covered process on the posteroventral margin of the male T9+ectoproct. The intermediate specimens are variable in adult characteristics, but they generally fall between the two species. (6) Egg size and larval characteristics (except the body length of the fully-fed first and third instars) do not differ between the two species. (7) The evolution of the wing variation is discussed.

Geographic variation in body and ovipositor sizes in the leaf beetle Plateumaris constricticollis (Coleoptera: Chrysomelidae) and its association with climatic conditions and host plants

Teiji SOTA, Masakazu HAYASHI, Tsuyoshi YAGI

Eur. J. Entomol. 104 (2): 165-172, 2007 | DOI: 10.14411/eje.2007.025


Plateumaris constricticollis
is a donaciine leaf beetle endemic to Japan, which lives in wetlands and uses Cyperaceae and Poaceae as larval hosts. We analyzed geographic variation in body size and ovipositor dimensions in three subspecies (constricticollis, babai, and toyamensis) in different climatic conditions and on different host plants. In addition, the genetic differentiation among subspecies was assessed using nuclear 28S rRNA gene sequences. The body size of subspecies toyamensis is smaller than that of the other subspecies; mean body size tended to increase towards the northeast. Ovipositor length and width are smaller in subspecies toyamensis than in the other subspecies. Although these dimensions depend on body size, ovipositor length still differed significantly between toyamensis and constricticollis-babai after the effect of body size was removed. Multiple regression analyses revealed that body size and ovipositor size are significantly correlated with the depth of snow, but not temperature or rainfall; sizes were larger in places where the snowfall was greatest. Haplotypes of the 28S rRNA gene sequence were not shared among the subspecies. Subspecies constricticollis and babai each had a unique haplotype, whereas subspecies toyamensis had four haplotypes, indicating differentiation among local populations within toyamensis. The evolution of body and ovipositor size in relation to habitat conditions and host plants is discussed.

New significant fossil insects from the Upper Carboniferous of Ningxia in northern China (Palaeodictyoptera, Archaeorthoptera)

Jakub PROKOP, Dong REN

Eur. 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.

Short-term indirect interactions between two moth (Lepidoptera: Noctuidae) species mediated by shared parasitoids: The benefit of being scarce

Tiit TEDER, Toomas TAMMARU

Eur. J. Entomol. 100 (3): 323-328, 2003 | DOI: 10.14411/eje.2003.051

Despite the impact of parasitoids on insect populations being extensively studied, indirect parasitoid-mediated effects remain rarely documented in natural communities. We examined the influence of shared parasitoids on the interactions between two functionally monophagous moths, Nonagria typhae and Archanara sparganii. The moths showed a considerable variation in terms of relative abundance and the degree of phenological synchrony between the species. On average, parasitism levels caused by shared parasitoids did not differ between the two host species. Relative parasitism levels of the two hosts, however, varied considerably among different samples. Percentage parasitism of the scarcer species, A. sparganii, thus could not be fully explained by that of the dominant species, N. typhae. The results indicated that A. sparganii may benefit from the presence of N. typhae. In particular, both low relative density as well as high phenological synchrony with N. typhae reduced parasitism levels in A. sparganii. The case thus indicates the presence of parasitoid-mediated indirect effects between the coexisting herbivores. The patterns of host use observed in this study are consistent with the scenario of frequency-dependent host use caused by changes in parasitoid behavior. Such a host use by parasitoids is suggested to promote numerical stability and coexistence of the moth species in the system studied.

Morphology and ultrastructure of the male reproductive system of the woolly beech aphid Phyllaphis fagi (Hemiptera: Aphididae: Phyllaphidinae)

Karina WIECZOREK, Piotr SWIˇTEK

Eur. 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.

Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)

Pablo César COLOMBO

Eur. J. Entomol. 105 (1): 59-64, 2008 | DOI: 10.14411/eje.2008.008

C. aquaticum (Acrididae: Leptysminae) inhabits water-hyacinths in the Neotropical region. The blue-flowered water-hyacinth, Eichhornia crassipes, has been introduced elsewhere without its natural enemies and has become a weed; recently C. aquaticum was considered as a possible biological control agent. In this work, six populations were sampled and cytologically studied. C. aquaticum has 2n = 23 chromosomes in males and 24 in females, with an X0/XX sex determination system. All chromosomes are acro-telocentric and the basic karyotype includes three Robertsonian (Rb) translocations between pairs 1/6, 2/5, and 3/4. These polymorphisms are restricted to the lower course of the Paraná river, between Rosario and Buenos Aires. Fusion frequencies increase southwards, thus showing a geographical cline. The polymorphisms mostly accord with Hardy-Weinberg and gametic phase equilibria. The rearrangements cause a drastic chiasma repatterning in the fusion bivalents (or trivalents) which reduces the proximal chiasma frequency. Recombination is also reduced due to the loss of independent segregation. A recombination index that takes into account both these factors correlates negatively with the number of pairs of chromosomes affected by fusions among populations, which does not accord with the "central-marginal" pattern.

Current knowledge on genes and genomes of phytophagous beetles (Coleoptera: Chrysomeloidea, Curculionoidea): a review

Jesús GÓMEZ-ZURITA, José GALIÁN

Eur. J. Entomol. 102 (4): 577-597, 2005

Fifteen years after the publication of the first genomic sequence of a phytophagous beetle, we review here the wealth of genetic and genomic information generated so far for the species-rich beetle superfamilies Chrysomeloidea (longhorn, seed and leaf beetles) and Curculionoidea (weevils and bark beetles). In this review we briefly describe the most common methods used to investigate the beetle genomes and also compile the nucleotide sequence information stored in public gene databases until December 2004. The motivations and relevance of these research initiatives are described in certain detail, distinguishing among structural and population studies, phylogenetic research, the study of genes involved in development and diapause, energetic metabolism, vegetal tissue digestion, and genes for insect resistance and defence.

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