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Incidence of infection of carabid beetles (Coleoptera: Carabidae) by laboulbenialean fungi in different habitatsShinji SUGIURA, Kazuo YAMAZAKI, Hayato MASUYAEur. J. Entomol. 107 (1): 73-79, 2010 | DOI: 10.14411/eje.2010.009 The prevalence of obligate parasitic fungi may depend partly on the environmental conditions prevailing in the habitats of their hosts. Ectoparasitic fungi of the order Laboulbeniales (Ascomycetes) infect arthropods and form thalli on the host's body surface. Although several studies report the incidence of infection of certain host species by these fungi, quantitative data on laboulbenialean fungus-host arthropod interactions at the host assemblage level are rarely reported. To clarify the effects of host habitats on infection by ectoparasitic fungi, the incidence of infection by fungi of the genus Laboulbenia (Laboulbeniales) of overwintering carabid beetles (Coleoptera: Carabidae) in three habitats, a riverside (reeds and vines), a secondary forest and farmland (rice and vegetable fields), were compared in central Japan. Of the 531 adults of 53 carabid species (nine subfamilies) collected in the three habitats, a Laboulbenia infection of one, five and one species of the carabid subfamilies Pterostichinae, Harpalinae and Callistinae, respectively, was detected. Three species of fungus were identified: L. coneglanensis, L. pseudomasei and L. fasciculate. The incidence of infection by Laboulbenia was higher in the riverside habitat (8.97% of individuals; 14/156) than in the forest (0.93%; 2/214) and farmland (0%; 0/161) habitats. Furthermore, the incidence of infection by Laboulbenia in the riverside habitat ranged from 0 to 33.3% and differed significantly in the ten microhabitats (riverbank, edge of track, tall reeds, kudzu vines, slope of a hollow, rotten wood, vine reeds, under stones, the shoulder of a terrace and marshy ground) where the carabid beetles overwintered. These results suggest that host habitats and microhabitats are closely associated with successful infection by laboulbenialean fungi. |
Bottom-up effects of host plant nutritional quality on Plutella xylostella (Lepidoptera: Plutellidae) and top-down effects of herbivore attack on plant compensatory abilityRana M. SARFRAZ, Lloyd M. DOSDALL, Andrew B. KEDDIEEur. J. Entomol. 106 (4): 583-594, 2009 | DOI: 10.14411/eje.2009.073 The plant stress and plant vigour hypotheses are competing paradigms pertaining to the preference and performance of herbivorous insects on their host plants. Tests of these hypotheses ideally require detailed information on aspects of soil nutrition, foliar nutrient levels and parameters of herbivore fitness, but such studies are uncommon. These hypotheses were tested using the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), reared on its host plant, Brassica napus (L.), grown in an experimental system of five nutrient regimes. Different levels of fertilizer treatments significantly affected the nutrient content of B. napus foliage and this in turn affected the preference and performance of P. xylostella. Ovipositing females discriminated among host plants grown in soils subjected to different fertilizer treatments and selected plants on which pre-imaginal survival was highest, development fastest and longevity of the next generation of adults the longest, even when food was scarce. Plants subjected to herbivory by P. xylostella responded by producing elevated levels of some nutrients (e.g., sulphur), but other nutrient levels declined in infested leaves (e.g., nitrogen). Regardless of the rate of fertilizer application, plants compensated for herbivory by increasing root mass compared to un-infested control plants; plants grown in soils receiving the optimum quantity of fertilizer developed the most robust root systems when infested. The plant stress and the plant vigour hypotheses are likely to be at the opposite ends of a continuum of responses between insects and their host plants. Our investigations indicate a complex set of interactions involving both bottom-up and top-down effects, which interact to affect host plant quality, oviposition site selection by female herbivores and the fitness of their offspring. |
Trurlia, a new Oriental genus of the tribe Cephenniini (Coleoptera: Scydmaenidae)Paweł JAŁOSZYŃSKIEur. J. Entomol. 106 (2): 261-274, 2009 | DOI: 10.14411/eje.2009.034 A new genus, Trurlia Jałoszyński, in the tribe Cephenniini (Scydmaenidae: Scydmaeninae) is described. The type species is T. insana sp. n. from Sumatra; females of an undescribed species are also reported to occur in W Malaysia. Trurlia most closely resembles Cephennomicrus Reitter, but it is the first genus of the Scydmaenidae with entirely fused antennomeres 10 and 11, forming a large, oval, abruptly separated club. Based on a disarticulated female of Trurlia sp., the detailed morphology of the new genus is described and illustrated, and possible relationships with other genera of the tribe are discussed. Comments on evolution, polarity of characters and feeding strategy of the Cephenniini are included. |
Revision of Xyalophora Kieffer and description of Xyalophoroides gen. n. (Hymenoptera: Figitidae: Figitinae)Mauricio JIMÉNEZ, Jordi PARETAS-MARTÍNEZ, Juli PUJADE-VILLAREur. J. Entomol. 105 (4): 751-769, 2008 The genus Xyalophora (Giraud, 1860) is revised herein. The revision includes the type species of Xyalophora (Figites clavatus Giraud, 1860), the type material and the original descriptions of all the species of Xyalophora included in the Weld catalogue, and long series of undetermined material. Xyalophora clavata (Giraud, 1860) and X. singularis (Ashmead, 1896) are the only currently recognized species that should be included in Xyalophora. Four new species are described: X. belizini sp. n., X. giraudi sp. n., X. provancheri sp. n. and X. zarazagai sp. n. The type species of Ceraspidia, Ceraspidia japonica Belizin, 1952, corresponds to males of a species within Xyalophora. Thus, Ceraspidia is a new synonymy of Xyalophora, which results in Xyalophora japonica comb. n. Xyalophora impatiens (Say, 1836) and Xyalophora picea (Spinola, 1853) being considered like incertae sedis, as the latter does not belong to the Figitinae but to the Eucoilinae and is probably a species within Acantheucoela Ashmead, 1900. Xyalophora aciculata Benoit, 1956 is transferred to the genus Figites Latreille, 1802: Figites aciculata comb. n. Xyalophora leviventris Kieffer, 1908 is a synonym of Xyalophora quinquelineata (Say, 1836), which is transferred to Xyalophoroides gen. n., a new genus here described. The differences between all the genera of Figitinae with a scutellar spine are discussed and illustrated. |
"DNA barcoding" is of limited value for identifying adelgids (Hemiptera: Adelgidae) but supports traditional morphological taxonomyMartina ŽUROVCOVÁ, Jan HAVELKA, Petr STARÝ, Pavlína VĚCHTOVÁ, Daniela CHUNDELOVÁ, Andrea JAROŠOVÁ, Lucie KUČEROVÁEur. J. Entomol. 107 (2): 147-156, 2010 | DOI: 10.14411/eje.2010.020 The sequence diversity in the mitochondrial cytochrome-c oxidase I (COI) gene was evaluated as a tool for resolving differences among species of European adelgids collected from several localities across the Czech Republic. Members of 7 genera and 16 species were examined, and as outgroups, two species of Phylloxeridae were used. Sequence divergences within species were on average less than 0.15%, whereas divergences between species ranged from 0.0 to 4.12% for congeneric and to 13.24% for intergeneric comparisons. It is concluded that DNA barcoding of Adelgidae is a powerful tool for identifying genera, but at the species level it works only in those cases where there are no species complexes. Nevertheless, it can be used as a complement to traditional, morphological taxonomy. |
Methoprene modifies adipokinetic hormone characteristics in the firebug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)Dalibor KODRÍK, Glenda ALQUICER, Radomír SOCHAEur. J. Entomol. 107 (1): 33-39, 2010 | DOI: 10.14411/eje.2010.003 In the present study the hypothesis that there is a feedback between juvenile hormone and adipokinetic hormones (AKHs) was investigated by topical application of the juvenoid methoprene on 9-day-old adult males of the firebug Pyrrhocoris apterus. This juvenoid (2 µg) induced a significant reduction of haemolymph lipids 24 h after treatment; however, it did not significantly reduce the ability of Pyrap-AKH (10 pmol/bug) to mobilize fat body lipids 6-72 h after the methoprene application. The same methoprene treatment elicited a significant increase of AKH content in the CNS (central nervous system: brain + corpora cardiaca + corpora allata) of experimental males 24 and 48 h after the juvenoid application. A significant decrease in the AKH level in the haemolymph was recorded at the same times and under the same experimental conditions. Similar results were observed when production of the AKHs from the CNS of topically treated males was measured under in vitro conditions. It is suggested that methoprene may reduce AKH release from the CNS resulting in an increase in the AKH content of the CNS due to accumulation rather than stimulation of AKH synthesis. Possible consequences of this phenomenon on the physiology of P. apterus are discussed. |
Seasonal occurrence and local coexistence within scarabaeid dung beetle guilds (Coleoptera: Scarabaeoidea) in Tunisian pastureFaïek ERROUISSI, Imen LABIDI, Saïd NOUIRAEur. J. Entomol. 106 (1): 85-94, 2009 | DOI: 10.14411/eje.2009.013 Dung beetle assemblages were monitored using baited pitfall traps from January to December 2006 in Northern Tunisia. 4,965 beetles belonging to 37 species were trapped. Aphodius lineolatus and Onthophagus taurus dominated the assemblages. Results showed a significant seasonal variation in assemblage composition, and diversity. There were four periods of activity during the course of the year. Temporal turnover was highest in October and in February. Temporal distribution of species shows seasonal segregation and opposite patterns in the two dominant guilds (Aphodiinae-dwellers and Scarabaeidae-tunnelers). Aphodiidae-dwellers were active from autumn to spring, although they were affected by summer drought. The Aphodius-dweller showed high temporal plasticity and phenological segregation. In contrast, Scarabaeidae-tunnelers were active all year round but mainly in the spring-summer period and less so in winter. Species in this guild showed a high degree of phenological overlap and a short ecological length. Our results suggest that coexistence in dung beetle guilds is facilitated by their phenological patterns, which reflect distinct ecological requirements and biogeographical origin of species. Geotrupidae-tunnelers and Scarabaeidae-rollers were rare and occurred mainly in the summer-autumn period, when individuals of the two other guilds were rare. |
New morphological data from the Jurassic of Inner Mongolia confirms the damselfly aspect of Protomyrmeleontidae (Insecta: Odonatoptera)Di-Ying HUANG, Julián F. PETRULEVIČIUS, André NELEur. J. Entomol. 107 (4): 615-620, 2010 | DOI: 10.14411/eje.2010.070 Protomyrmeleon daohugouensis sp. n. and Protomyrmeleon lini sp. n., two new species of Protomyrmeleontidae from the Middle Jurassic of Jiulongshan Formation are the first Chinese representatives of this Mesozoic odonatopteran family. The type specimen of P. lini is exceptionally well preserved, showing several particular wing and body structures that were unknown, viz. unique shape of tarsal claws, extreme thoracic skewness, presence of three pairs of long spurs on all femora and tibiae. The type "A" (sensu Nel et al., 2005) of wing venation (i.e. with a very long bridge between IR2 and RP3/4) corresponds to that of the protomyrmeleontid fore wing. The nearly complete absence of the meso-metathoracic interpleural suture, newly discovered in the Protomyrmeleontidae, can be considered as a synapomorphy of the clade Protozygoptera + Odonata. |
A swarm of the seven-spot ladybird Coccinella septempunctata (Coleoptera: Coccinellidae) carried on a cruise shipDan MINCHINEur. J. Entomol. 107 (1): 127-128, 2010 | DOI: 10.14411/eje.2010.016 Several thousands of the seven-spot ladybird Coccinella septempunctata L., descended upon a cruise ship over several hours in daylight while in port in Morocco in April 2009. The ship had recently arrived from South America. Despite a treatment of fumigation beetles were found living after fourteen days following the inoculation event. This observation indicates an ocean transmission of large numbers of this species could take place and might have happened in the past. |
Do covers influence the capture efficiency of pitfall traps?Sascha BUCHHOLZ, Karsten HANNIGEur. J. Entomol. 106 (4): 667-671, 2009 | DOI: 10.14411/eje.2009.083 Pitfall traps are widely used in terrestrial ecology to capture ground-dwelling arthropods. In order to determine the effect of covers placed over pitfall traps on their efficiency at capturing of spiders, carabid beetles and ants, four types of pitfall trap were sunk into the ground at dry grassland sites: three pitfall traps were not covered, three were covered with white, three with green and three with black plastic covers. The total catch was 9,364 spiders, 4,352 carabid beetles and 4,157 ants. The distribution of species of spiders and carabid beetles, and the total catch of spiders, carabid beetles and ants did not differ significantly among the four types of trap. Therefore, covers do not appear to affect the capture efficiency of pitfall traps. |
Laboratory study of the effects of leek lectin (APA) in transgenic tobacco plants on the development of cotton leafworm Spodoptera littoralis (Lepidoptera: Noctuidae)Amin SADEGHI, Guy SMAGGHE, Esmeralda JURADO-JÁCOME, Willy J. PEUMANS, Els J.M. VAN DAMMEEur. J. Entomol. 106 (1): 21-28, 2009 | DOI: 10.14411/eje.2009.003 Transgenic tobacco plants expressing the Allium porrum L. (leek) agglutinin (called APA) under the control of the 35S constitutive promoter were tested for their insecticidal activity against the cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae). Southern blot and PCR analysis confirmed that the APA gene was integrated into the plant genome. Northern and Western blots as well as semi-quantitative agglutination assays revealed lectin expression at various levels in the transgenic lines. Biochemical analyses indicated that the recombinant APA has the same molecular structure as the native lectin. Native and recombinant lectin have the same N-terminal amino acid sequence. Bioassays using detached leaves from transgenic tobacco plants demonstrated that the ectopically expressed APA significantly (p < 0.05) reduced the weight gain of 2nd-instar larvae of S. littoralis. This inhibitory effect was observed throughout the experiment and on day 11 the caterpillars fed on transgenic tobacco leaves were 25-30% lighter in weight than the control caterpillars fed on wild type plants. In addition the lectin retarded the development of the larvae and metamorphosis, reduced pupal weight and increased mortality rate. These findings suggest that APA is a suitable insect resistance protein for integrating into plant genomes for controlling S. littoralis. |
Cytotaxonomy and karyology of the tribe Otiorhynchini (Coleoptera: Curculionidae)Dorota LACHOWSKA, Maria ROŻEK, Milada HOLECOVÁEur. J. Entomol. 105 (2): 175-184, 2008 | DOI: 10.14411/eje.2008.026 A cytogenetic study of bisexual species belonging to the genera Cirrorhynchus, Dodecastichus and Otiorhynchus is presented in order to confirm their taxonomic position. The karyotype characterization was accomplished by an analysis of mitotic and meiotic chromosomes after differential staining, namely by C-banding, silver impregnation, DAPI and CMA3. A review of the cytogenetic data for the tribe Otiorhynchini contributed to knowledge of chromosomal evolution in this group. An investigation of five of the species studied showed some similarities such as a sex chromosome system of "parachute type" (Xyp), the presence of 10 autosomal bivalents (2n = 22) and heterochromatin localized around centromeres. These observations are similar to those already described for Otiorhynchini species, and confirm the karyological conservatism of this weevil group. In contrast, another species Cirrorhynchus kelecsenyi has an additional four autosomal bivalents (n% = 14 + Xyp, 2n = 30), which differs considerably from the chromosomal homogeneity of the other genera. Karyotypic evolution in this species was achieved most probably by increasing the number of chromosomes by centric fissions, resulting in variation in the number of acrocentric chromosomes. DAPI-positive and CMA3-negative reactions of heterochromatic DNA in all the species studied suggest that it has an AT-rich composition. Impregnating chromosomes with silver nitrate reveals NORs on one pair of autosomes, and probably argentophilic material in the interspace between the X and y sex chromosomes. The karyological findings support the taxonomical revision of Otiorhynchini based on morphological characters. |
Patch size and connectivity influence the population turnover of the threatened chequered blue butterfly, Scolitantides orion (Lepidoptera: Lycaenidae)Atte KOMONEN, Tuuli TIKKAMÄKI, Niina MATTILA, Janne S. KOTIAHOEur. J. Entomol. 105 (1): 131-136, 2008 | DOI: 10.14411/eje.2008.018 Chequered blue butterfly, Scolitantides orion (Lepidoptera: Lycaenidae) has severely declined in many parts of Europe and is currently red-listed in many countries. We studied the population structure and turnover of the species in a lake-island system in a National Park in eastern Finland over a three-year period. The incidence of the chequered blue on the suitable islands (n = 41) and habitat patches (n = 123) was high: an average of 82% of the islands and patches were occupied over the three year period. At the island scale, the annual population turnover rate was 17%, with an extinction and colonization rate of 7% and 10%, respectively. At the patch scale, the annual population turnover was 16%, with 7% extinction and 9% colonization rate. Islands that were occupied over the three year period had a larger area of suitable habitat than islands in which turnover events were observed. At the patch scale, turnover events were observed in small and poorly connected patches. Patchy occurrence of the host plant and observed extinction-colonization dynamics suggest that the chequered blue population confirms a metapopulation structure. Although the local populations are small, the observed high patch occupancy and balanced population turnover indicates that the metapopulation is not in immediate risk of extinction. |
Revision of the bee genus Capicola (Hymenoptera: Apoidea: Melittidae) distributed in the Southwest of AfricaDenis MICHEZ, Connal EARDLEY, Michael KUHLMANN, Sébastien PATINYEur. J. Entomol. 104 (2): 311-340, 2007 | DOI: 10.14411/eje.2007.048 The bee family Melittidae (Hymenoptera: Apoidea) includes 14 genera. Most have been reviewed but not the small African genus Capicola. The present work aims to fill this gap. Based on the revision of the type material and 1272 additional specimens, we provide a comprehensive synonymic and annotated catalogue of the 12 Capicola species sensu Michener (1981). Lectotypes are designated for the previously established species Capicola braunsiana (= C. obscura syn. n.), C. cinctiventris, C. femorata, C. flavitarsis and C. rufiventris. Moreover, C. danforthi sp. n., C. flavicara sp. n., C. gessorum sp. n., C. micheneri sp. n., and C. richtersveldensis sp. n., are newly described, as well as the previously unknown female of C. nanula, male of C. nigerrima and male of C. rhodostoma. New synonymies are proposed for C. braunsiana (= C. obscura) and C. flavitarsis (= C. cinctiventris). An original dataset of 20 morphological characters is used for the inference of the 12 species' phylogenetic relationship. A key to species is provided. In addition, the ranges of the 12 taxa are mapped and discussed. This paper contributes to a global revision of the Melittidae. |
Redefinition of the Clusiinae and Clusiodinae, description of the new subfamily Sobarocephalinae, revision of the genus Chaetoclusia and a description of Procerosoma gen. n. (Diptera: Clusiidae)Owen LONSDALE, Stephen A. MARSHALLEur. J. Entomol. 103 (1): 163-182, 2006 | DOI: 10.14411/eje.2006.020 The higher classification of the Clusiidae is reviewed, and the family is divided into the subfamilies Clusiodinae, Clusiinae and the new subfamily Sobarocephalinae, all of which are (re)defined. The newly defined Clusiinae includes the genera Phylloclusia Hendel, 1917, Tetrameringia McAlpine, 1960, Amuroclusia Mamaev, 1987, Clusia Haliday, 1838, Paraclusia Czerny, 1903, Alloclusia Hendel, 1917 and Apiochaeta Czerny, 1903. The Sobarocephalinae includes the genera Sobarocephala Czerny, 1903, Procerosoma gen. n., and Chaetoclusia Coquillett, 1904. The new genus Procerosoma is described for two species, Procerosoma alini (Shatalkin) comb. n. from Brazil and P. prominens sp. n. from Mexico. Sobarocephaloides Soós, 1962 is treated as a junior synonym of Sobarocephala, and Chaetoclusia is redefined to include the monotypic genera Chaetoclusiella Soós, 1962, syn. n. and Trichoclusia Soós, 1962, syn. n. Six new species of Chaetoclusia are described (C. centrofasciata sp. n., C. amplipenis sp. n., C. transversa sp. n., C. inbionella sp. n., C. flava sp. n., and C. furva sp. n.). Chaetoclusia bakeri peruana Hennig, 1938 is included as a junior synonym of C. bakeri Coquillett, 1904. The phylogeny of Chaetoclusia is discussed and a key is provided for its 13 species. |
Selective oviposition in fertilized seed of Ilex integra by the wasp Macrodasyceras hirsutum (Hymenoptera: Torymidae)Etsuro TAKAGI, Kazunobu IGUCHI, Masanori SUZUKI, Katsumi TOGASHIEur. J. Entomol. 107 (2): 197-202, 2010 | DOI: 10.14411/eje.2010.026 It is speculated that the wasps that attack the seeds of gymnosperm trees (conifers) before they are fertilized can induce unfertilized seeds to accumulate storage material whereas those that attack after the seeds are fertilized selectively oviposit in fertilized seeds. Moreover, in the case of the wasps that oviposit after fertilization of seed, the presence of unfertilized seeds and seedless fruit may increase plant fitness via reduced parasitism of the viable seed. To determine the relationship between the two strategies, host manipulation or selective oviposition, and the time of fertilization of the seeds of angiosperm host plants, fertilized seed of Ilex integra Thunb. was dissected out of berries either immediately after the flight of the seed wasp Macrodasyceras hirsutum Kamijo in the field or the death of adults in the laboratory. The wasps oviposited mostly in fertilized seeds and rarely in unfertilized seeds. Unfertilized seeds, produced by flowers enclosed in pollen exclusion bags, and then exposed to wasps did not contain immature wasps or storage material, which indicates that the wasp did not oviposit in unfertilized seeds. These results support the above mentioned hypothesis and indicate that the substantial proportion of seedless berries do not function as an egg sink. |
Habitat preferences influencing populations, distribution and conservation of the endangered saproxylic beetle Cucujus cinnaberinus (Coleoptera: Cucujidae) at the landscape levelJakub HORÁK, Eva VÁVROVÁ, Karel CHOBOTEur. J. Entomol. 107 (1): 81-88, 2010 | DOI: 10.14411/eje.2010.011 Cucujus cinnaberinus (Scopoli, 1763) is a saproxylic beetle listed in the IUCN Red List and the European Habitats Directive. Although the species is highly protected and often red-listed little is known about its ecological requirements and status of its populations. Therefore, our main aims were to review its current and historical distributions and status of C. cinnaberinus populations in Europe and to determine its recent habitat preferences at the landscape level in the Czech Republic, where the increasing number of records over the last few years indicates a possible increase in abundance of this beetle. Cucujus cinnaberinus is closely associated with soft-wood and broad leaved trees and is able to colonize man-made habitats from persisting local populations if there is a sufficient supply of suitable dead wood. This beetle is not restricted to old-growth forests or even relict woodland, as previously reported, but currently predominantly inhabits abandoned planted stands of trees like lignicultures or avenues, which have an open canopy. Colonization of stands dominated by hybrid poplars probably resulted in the recent increase in the number of records of this species in the central European countries. However, this could present problems for the protection of this species in future, because the trees in these stands are gradually dying and are not being replaced. The decline and extinction of C. cinnaberinus on the northern and southern edges of its distribution was probably caused by the absence of soft-wooded broadleaved trees in intensively managed forests and other more suitable habitats. |
Experimental evidence for density-determined wing dimorphism in two bush-crickets (Ensifera: Tettigoniidae)Dominik PONIATOWSKI, Thomas FARTMANNEur. J. Entomol. 106 (4): 599-605, 2009 | DOI: 10.14411/eje.2009.075 Macroptery is common in many species of Orthoptera, but the causes are still discussed. Besides the assumption that macroptery is genetically determined, there is evidence that wing dimorphism is induced by environmental factors, particularly population density. However, most of the research is on pest species. In contrast, knowledge of wing dimorphism in species that occur at low population densites is still poor. Our study aims to test how density actually affects macroptery. As model organisms we chose two bush-cricket species of the genus Metrioptera (Ensifera: Tettigoniidae): While long-winged M. roeselii (Hagenbach, 1822) occur regularly, macropterous M. brachyptera (Linnaeus, 1761) are rare and are never observed outside their mating habitat. Nymphs of populations from the range core of both species (340 individuals each) were reared in groups of three and six individuals per 500 cm3 box, and individually. Our analyses revealed that development of macropters was mainly affected by the initial rearing densities. Compared with those reared individually the number of macropters was significantly higher among individuals reared at medium and high densities. The percentage of macropterous individuals was about twice as high in M. brachyptera as in M. roeselii, and the development of macropters significantly differed between the two species. These findings lead to the conclusion that macropterism is mainly influenced by density stress in both bush-crickets. Genetically determined wing dimorphism is unlikely, otherwise the observed high numbers of long-winged individuals of M. brachyptera, which are very rare under natural conditions, would never have developed in the laboratory. Macropterous M. brachyptera may rarely be found in the field, but we argue that this is due to low natural densities and, accordingly, to rare exposure to density stress. |
Pre-diapause mating and overwintering of fertilized adult females: New aspects of the life cycle of the wing-polymorphic bug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)Radomír SOCHAEur. J. Entomol. 107 (4): 521-525, 2010 | DOI: 10.14411/eje.2010.059 New aspects of the life-cycle of the flightless wing-polymorphic bug Pyrrhocoris apterus (L.) are described. It was found that 1.1-14.9% of the adult females of P. apterus in 11 samples collected from 4 populations in the South Bohemia had mated prior to entering diapause and their ovaries were in the pre-vitellogenic stage of development with viable sperm in their spermathecae. Some of these females successfully overwintered. The percentage of overwintering females that had been fertilized ranged from 1.1 to 7.2 % and depended on the month and year of collection. The results indicate that pre-diapause mating and overwintering of fertilized females is not unusual in populations of P. apterus in the Czech Republic and and that sperm in overwintering female survives for at least 7-8 months. |
A review of Fennoscandian arthropods living on and in snowSigmund HÅGVAREur. J. Entomol. 107 (3): 281-298, 2010 | DOI: 10.14411/eje.2010.037 A permanent snow cover for several months is typical for large parts of Norway, Sweden and Finland. Snow layers thicker than about 20 cm insulate the soil surface and stabilize the ground temperature close to 0°C. Many ground-living invertebrates are active at this temperature in the subnivean air space. From this "base camp", some invertebrates migrate upwards to use the snow as a substrate. The intranivean fauna consists of springtails (Collembola) and mites (Acari) that are small enough to move within the narrow pores between snow crystals. The supranivean fauna consists of various invertebrates that are active on the snow surface. Some of them are Collembola that have migrated through the snow layers. However, most of them are larger insects and spiders which migrate between the subnivean and supranivean habitats following air channels which are naturally created along tree stems, bushes etc. penetrating the snow. Likewise, certain Chironomidae and Plecoptera, hatching from winter-open rivers and brooks, are active on the snow surface. The supranivean arthropod fauna has the following characteristics: 1. It is a weather dependent assemblage of species, coming and going with changes in air temperature, cloud cover, and wind. Below ca. -6°C animals are absent, but at temperatures around or above zero, many groups can be simultaneously active on snow. 2. The snow surface fauna shows phenological changes throughout the winter, as certain species and groups are mainly active during certain months. 3. Some invertebrates are highly specialized and take advantage of the snow surface as an arena in their life cycle. Examples are Hypogastrura socialis (Collembola), and the two wingless insects Chionea sp. (Diptera: Limoniidae) and Boreus sp. (Mecoptera). They use the smooth snow surface for efficient migration. Chionea sp. and Boreus sp. lay their eggs during the snow-covered period, while H. socialis migrates to create new colonies. The cold tolerant spider Bolephthyphantes index is unique in constructing webs in small depressions on the snow, to catch migrating Collembola. Various adaptations for using the snow as a substrate are discussed. Besides physiological and morphological adaptations, snow surface arthropods show special behavioural adaptations. Most conspicuous is the ability of several Collembola species to navigate during migration, using the position of the sun for orientation. Furthermore, in Collembola and Mecoptera, jumping as an original mechanism to escape predators has independently evolved into a migrating mechanism. An evolutionary potential exists for more invertebrate groups to take advantage of snow as a substrate in their life cycle. For instance, several more cold tolerant spiders might evolve the ability to catch migrating Collembola on snow. |
Intraguild interactions between the predatory hoverfly Episyrphus balteatus (Diptera: Syrphidae) and the Asian ladybird, Harmonia axyridis (Coleoptera: Coccinellidae): Effect of larval tracksRaki ALMOHAMAD, François J. VERHEGGEN, Frédéric FRANCIS, Eric HAUBRUGEEur. J. Entomol. 107 (1): 41-45, 2010 | DOI: 10.14411/eje.2010.004 The effects of the larval tracks of Episyrphus balteatus DeGeer (Diptera: Syrphidae) and Harmonia axyridis Pallas (Coleoptera: Coccinellidae) on the egg laying behavior of females of the predatory hoverfly E. balteatus were investigated in two-choice experiments. The oviposition response of H. axyridis to larval tracks of E. balteatus was also tested in one-choice experiments. Gravid E. balteatus females laid significantly fewer eggs on leaf discs with aphids and contaminated with tracks of conspecific or heterospecific larvae than on control leaf discs. H. axyridis females laid similar numbers of eggs in Petri dishes with aphids and contaminated with the tracks of E. balteatus larvae as in control Petri dishes. This indicates that E. balteatus females lay fewer eggs at sites where there are conspecific and heterospecific larval tracks, whereas the tracks of the syrphid larvae did not deter H. axyridis females from laying eggs. |
Enhanced tolerance to water stress in adults of the South India strain of the seed beetle, Callosobruchus maculatus (Coleoptera: Bruchidae), as a product of large body sizeJay A. YODER, Brady S. CHRISTENSEN, George D. KEENEYEur. J. Entomol. 107 (2): 271-275, 2010 | DOI: 10.14411/eje.2010.035 A water balance study was conducted on newly-emerged adults of seed beetle, Callosobruchus maculatus, to explore how South India strain survives longer than Brazil strain in laboratory cultures. No difference between strains was noted with regard to dehydration tolerance, and water conservation features confirm classification of this species as xerophilic. There was no evidence for critical transition temperature (CTT), thereby safeguarding against excessive water loss as the temperature rises, or for critical equilibrium humidity (CEH), indicating that water is imbibed as a liquid. In contrast to the Brazil strain, adults of the South India strain were distinguished by a larger body size, resulting in a lower net transpiration rate with suppressed activation energy (Ea, permeability constant) for water loss, and a lower percentage body water content due to a higher dry mass (fat). These modifications for water balance of the South India strain link enhancing time for reproduction and distribution spread in the adult with the higher seed consumption/respiratory rate trait that has been previously reported for larvae of this strain. |
Genetic diversity of the xerothermic weevils Polydrusus inustus and Centricnemus leucogrammus (Coleoptera: Curculionidae) in central EuropeLukasz KAJTOCH, Dorota LACHOWSKA-CIERLIK, Mieczyslaw MAZUREur. J. Entomol. 106 (3): 325-334, 2009 | DOI: 10.14411/eje.2009.040 Phylogeography, genetic diversity, and demography of central European populations of two flightless xerothermic weevils, Polydrusus inustus and Centricnemus leucogrammus, were studied based on the polymorphism of three mtDNA genes (COII, CytB, and ND1). Results indicate that these xerothermic beetles may have different origins. P. inustus is a recent migrant as the parthenogenetic form has a low level of genetic diversity and lacks a geographic population structure. This is probably a result of a recent (before the end of last glaciation) expansion and/or present dispersal mediated by humans. On the other hand, C. leucogrammus appears to be a relic species as the populations of this species are much more genetically diverse (six distinct clades) and some of the populations are allopatric and others sympatric. They probably diverged and expanded during the last few glaciations. Genetic discontinuities were detected among localities that are now separated by gaps in the distribution. Boundaries (mountains or farmland) separate the populations into three groups: (1) Moravia and Slovakia, (2) the lower Vistula Valley in northern Poland and (3) south-eastern Poland together with western Ukraine. Evidence for recent gene flow was found only among populations from south-eastern Poland and western Ukraine, and between these two groups. One population from northern Poland was surprisingly related to populations in southern Poland, which may be due to extinction of intermediate populations. |
Food consumption and immature growth of Adalia bipunctata (Coleoptera: Coccinellidae) on a natural prey and a factitious foodMohammad A. JALALI, Luc TIRRY, Patrick DE CLERCQEur. J. Entomol. 106 (2): 193-198, 2009 | DOI: 10.14411/eje.2009.024 One factor limiting the adoption of aphidophagous coccinellids in augmentative biological control is cost-effective mass production. The use of factitious foods may lower production costs by reducing space and manpower requirements for mass rearing of the predator and its prey and by enhancing mechanization of rearing procedures. The objective of this study was to compare the efficiency of food conversion, consumption indices and growth rates of first to fourth instars of Adalia bipunctata when fed either a mixture of Ephestia kuehniella eggs and fresh bee pollen, or on the natural prey Myzus persicae. Larval survival did not differ among treatments, averaging 80 and 90% on the respective diets. Mean dry body weights of the coccinellid were significantly lower on M. persicae than on the factitious food only for second instars and the pre-pupal stage. Dry food consumption by the predator throughout larval development averaged 20.61 mg on factitious food and 14.82 mg (corresponding to an average of 284 third and fourth instars) on M. persicae. The efficiency of conversion of ingested food for total larval development averaged 25 and 30% on factitious food and aphids, respectively. The relative growth rate of the larval instars was higher on aphids, whereas the consumption index was higher on the mixture of E. kuehniella eggs and pollen. An additional experiment showed that rearing the previous instars on the factitious food had no substantial effect on aphid consumption in the fourth instar. The study suggests that this factitious diet may be an appropriate food source for mass rearing A. bipunctata. |
Effectiveness of two sampling methods used for collecting Ichneumonidae (Hymenoptera) in the Cabañeros National Park (Spain)Marina MAZÓN, Santiago BORDERAEur. J. Entomol. 105 (5): 879-888, 2008 | DOI: 10.14411/eje.2008.116 When estimating the species richness of a taxonomic group in a specific area, the choice of the trapping method is extremely important. In this study the effectiveness of Malaise and Moericke yellow pan traps for collecting flying Ichneumonidae was compared. Samples were collected in 5 habitats in the Cabañeros National Park: pastureland, shrubland and three types of woodland. Two traps of each type were placed in each habitat, and samples collected over a period of one year, replacing the pots every 20 days. The study focused on eleven subfamilies of Ichneumonidae. The results showed that the composition of the Ichneumonidae in the catches of the two traps differed. Malaise traps were more effective in collecting Ichneumonidae in all habitats, but especially in the ash woodland. Moericke traps yielded the most abundant catches in open areas with a wider field of vision. The subfamily Orthocentrinae occurred more frequently in the Moericke yellow traps. The Ichneumonidae caught by both trapping methods differed, especially in the relative abundance of the most common species. When compiling an inventory of species it is extremely important to use a combination of both trapping methods. |
Resources for British butterflies (Lepidoptera: Hesperioidea, Papilionoidea). The alien consumer component and its significance for butterfly habitatsPeter B. HARDY, Roger L.H. DENNISEur. J. Entomol. 105 (4): 649-657, 2008 With climatic warming there is an expectation that phytophagous insects will increasingly use alien (non native) plants as nectar sources and larval host plants. Alien plant use is investigated in British butterflies. Butterflies are considered to be larval host plant specialists relative to their use of nectar plants. Supporting this view, use of alien plants as nectar sources (50.1%, 27 novel plant families) is almost twice that of their use as larval host plants (21.6%; three novel plant families). Some 80% of the variation in percent alien nectar plant use is accounted against 30% of that for percent alien host plant use. The key variable accounting for alien plant use is butterfly mobility. Other prominent variables that facilitate access to alien nectar plants are southern distributions, longer adult life span, host plants in garden biotopes. A different set of variables additionally account for alien host plant exploitation (% alien host plant use: woody host plants; number of alien host plants: polyphagy; greater abundance of native host plants in gardens). Although threatened butterfly species do not depend on alien plants, this may well reflect on specialisation in resource use accompanying habitat fragmentation and an inability to use novel resources that are becoming increasingly available. Detailed study of alien resources is advocated to assess the importance of alien plant resources for phytophagous insects. |
Sycophila pistacina (Hymenoptera: Eurytomidae): A valid speciesHosseinali LOTFALIZADEH, Gérard DELVARE, Jean-Yves RASPLUSEur. J. Entomol. 105 (1): 137-147, 2008 | DOI: 10.14411/eje.2008.019
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Ecological factors determining the density-distribution of Central European dragonflies (Odonata)Filip HARABIŠ, Aleš DOLNÝEur. J. Entomol. 107 (4): 571-577, 2010 | DOI: 10.14411/eje.2010.066 Habitat specificity is the most important factor affecting the regional distribution of dragonflies. Nevertheless, species with the highest specificity are not always the scarcest. Several important determinants of dragonfly density-distribution relationships were identified. Altitude preference and altitude range are significantly associated with dragonfly distribution. Some of the species that are habitat specialists but occur over a wide range of altitudes should be classified as rare but not endangered. This very simple principle is based on the assumption that habitat specialists have a very limited number of suitable biotopes. Obviously, dragonflies with a marginal distribution prefer a narrow range of altitudes (especially in terms of temperature limitation) and biotopes (effect of biogeography, marginality). Surprisingly, there is no "critical" life stage that is significantly associated with the regional distribution of dragonflies, although most species spend most time in the larval stage. Knowledge of the dispersal ability of particular species is limited, although it could significantly affect species survival and distribution. |
Predator dependent mimetic complexes: Do passerine birds avoid Central European red-and-black Heteroptera?Kateřina HOTOVÁ SVÁDOVÁ, Alice EXNEROVÁ, Michala KOPEČKOVÁ, Pavel ŠTYSEur. J. Entomol. 107 (3): 349-355, 2010 | DOI: 10.14411/eje.2010.044 True bugs are generally considered to be well protected against bird predation. Sympatric species that have similar warning coloration are supposed to form a functional Müllerian mimetic complex avoided by visually oriented avian predators. We have tested whether these assumptions hold true for four species of European red-and-black heteropterans, viz. Pyrrhocoris apterus, Lygaeus equestris, Spilostethus saxatilis, and Graphosoma lineatum. We found that individual species of passerine birds differ in their responses towards particular bug species. Great tits (Parus major) avoided all of them on sight, robins (Erithacus rubecula) and yellowhammers (Emberiza citrinella) discriminated among them and attacked bugs of some species with higher probability than others, and blackbirds (Turdus merula) frequently attacked bugs of all the tested species. Different predators thus perceive aposematic prey differently, and the extent of Batesian-Müllerian mimetic complexes and relations among the species involved is predator dependent. |
Species coexistence patterns in a mycophagous insect community inhabiting the wood-decaying bracket fungus Cryptoporus volvatus (Polyporaceae: Basidiomycota)Kohmei KADOWAKIEur. J. Entomol. 107 (1): 89-99, 2010 | DOI: 10.14411/eje.2010.012 A study of the insect community inhabiting the wood-decaying bracket fungus, Cryptoporus volvatus was used to test two hypotheses proposed to account for the competitive coexistence of species in insect communities in patchy environments, niche partitioning and spatial mechanisms. A total of 8990 individuals belonging to 17 insect species emerged from 438 sporocarps (patches) collected from the field. Insect species richness increased and then declined with increase in the total insect biomass reared from a sporocarp, suggesting the potential importance of interspecific competition. Successional niche partitioning explained the spatial distribution of the four specialist species. The aggregation model of coexistence satisfactorily explained the stable coexistence of the species. The specialist species displayed higher population persistence than the generalists. Simulation studies suggest that restricted movements of adults could override patch-level larval aggregation. The effect of such restricted movements on stabilizing coexistence in fungus-insect communities has not been previously appreciated. These findings suggest that spatial mechanisms play a crucial role in the competitive coexistence of the species in the mycophagous insect communities inhabiting bracket fungi. |



