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Habitat use governs distribution patterns of saprophagous (litter-transforming) macroarthropods - a case study of British woodlice (Isopoda: Oniscidea)Bethan V. PURSE, Steve J. GREGORY, Paul HARDING, Helen E. ROYEur. J. Entomol. 109 (4): 543-552, 2012 | DOI: 10.14411/eje.2012.068 Despite the importance of saprophagous macroarthropods as key facilitators of plant litter decomposition within ecosystems and their likely sensitivity to global climate change and land-use change, a lack of ecological data has precluded attempts to explain their distribution patterns in terms of traits. Using an extensive set of large-scale and long-term biological records, the distribution patterns of 33 woodlice (Crustacea: Oniscidea) species in Britain were characterised by their range size (area of occupancy) and aggregation (degree to which occupied squares are clustered across the range). Body size and seven ecological traits were examined as correlates of range size and fill, while controlling for phylogeny and recording intensity, and comparing fine and broad-scale measures of habitat heterogeneity. Species that used a greater diversity of habitats had larger range sizes. Broad categorisation of habitats (by dominant vegetation) alongside other traits was less accurate in predicting range size than fine-scale habitat (microsites where individuals were discovered) data. The latter explained 25% more variance than broad-scale habitat data, highlighting the value of coupling biological recording of species with data on micro-habitat. Habitat use is an important trait in explaining distribution patterns and we conclude that ensuring land cover heterogeneity will favour conservation of saprophagous macro-arthropod diversity. |
Genus-group names of Afrotropical flea beetles (Coleoptera: Chrysomelidae: Alticinae): Annotated catalogue and biogeographical notesMaurizio BIONDI, Paola D'ALESSANDROEur. J. Entomol. 107 (3): 401-424, 2010 | DOI: 10.14411/eje.2010.049 This paper consists of an up to date annotated catalogue of the Afrotropical genera of Alticinae (Chrysomelidae), with biogeographical notes on the flea beetle fauna occurring in Sub-Saharan Africa and Madagascar. The following new synonymies are proposed: Eugonotes Jacoby, 1897 (a subgenus of Sanckia Duvivier, 1891) = Brancucciella Medvedev, 1995 syn. n.; Amphimela Chapuis, 1875 = Dibolosoma Jacoby, 1897 syn. n.; Amphimela Chapuis, 1875 = Halticova Fairmaire, 1898 syn. n.; Podagrica Chevrolat, 1837 = Podagrixena Bechyné, 1968 syn. n.; Aphthona Chevrolat, 1837 = Pseudeugonotes Jacoby, 1899 syn. n.; Nisotra Baly, 1864 = Pseudonisotra Bechyné, 1968 syn. n. The following new combinations are proposed: Afrorestia sjostedti (Weise, 1910) comb. n. (from Crepidodera); Bechuana natalensis (Jacoby, 1906) comb. n. (from Ochrosis); Sesquiphaera natalensis (Jacoby, 1906) comb. n. (from Sphaeroderma). The genus Hildenbrandtina Weise, 1910 is trasferred from Galerucinae to Alticinae. New distributional data for many genera in the Afrotropical region is provided. |
Variation in the shape of the wings and taxonomy of Eurasian populations of the Calopteryx splendens complex (Odonata: Calopterygidae)Saber SADEGHI, Henri J. DUMONTEur. J. Entomol. 111 (4): 575-583, 2014 | DOI: 10.14411/eje.2014.073 We used geometric morphometrics to determine variation in the morphology of the forewings of individuals in 20 populations of Calopteryx splendens s.l. in Eurasia and related these to the circum-specific taxonomy of this taxon. We found differences in shape, with the largest and smallest centroid size of the wings in adjacent northern (orientalis) and western (intermedia) populations in Iran, respectively, so isolation and relationship are not necessarily determined by distance, but often associated with the stream basin inhabited. The variation in wing shape, however, was much greater. with Populations at the eastern edge of the range (Tajikistan, Kyrgyzstan and East Kazakhstan) uniquely different. Oddly, no taxonomic name is associated with them, although they may be among the oldest representatives of the splendens complex. The European and Asian populations are in two separate clades. One of these includes insects with no to a medium-sized wing spot, which does not reach the tip of the wing (waterstoni-group), while the other includes insects with very broad wing spots, or, when short, it extends to the very tip of the wings and most females are androchrome (ancilla or intermedia group). Turkmenistan and northern Iranian population form a separate line inside this clade, which we equate with Calopteryx orientalis. South Albanian and Greek populations are in a separate branch corresponding to ssp. balcanica; two populations from Ireland and Italy form a branch that has no equivalent in traditional taxonomy, while Calopteryx xanthostoma was not identified by its wing shape. Understanding this multitude of phenotypes and the enormous amount of variation within certain populations but not in others becomes easy if one assumes there were two probable late Pleistocene waves of migration, the first of insects lacking spots that migrated east and westwards from the South Black Sea basin, the second, perhaps from the west Caspian, composed of heavily spotted insects with androchromic females. The hybridization between these two waves resulted in the current plethora of colour forms and accounts for why similar phenotypes may turn up independently in widely distant locations. |
Long-term partitioning of space between two territorial species of ants (Hymenoptera: Formicidae) and their effect on subordinate speciesWojciech CZECHOWSKI, Bálint MARKÓ, Alexander RADCHENKO, Piotr ¦LIPIÑSKIEur. J. Entomol. 110 (2): 327-337, 2013 | DOI: 10.14411/eje.2013.046 Competition is a major force organizing ant communities and results in co-occurring species evolving different strategies for foraging and use of space. Territorial species, as top dominants exclude each other, while shaping the local ant communities both qualitatively and quantitatively. In this study we examined how two territorial species, Formica polyctena and Lasius fuliginosus, can coexist in adjacent territories over long periods of time, and whether they affect co-occurring species of ants in different ways. Field observations in the absence and in the presence of baits were carried out around a L. fuliginosus nest complex surrounded by a polydomous F. polyctena colony in S Finland in 2007-2009. Both species controlled their territories, but were affected by changes in the abundance of the other species and the distance from L. fuliginosus' main nest. They did not have the same effect on the subordinate species in the absence of baits, but the abundance of Myrmica spp. recorded at baits was negatively affected by both of the territorial species. The preferences of the different species for the artificial food sources differed: L. fuliginosus and F. polyctena preferred tuna to honey and Myrmica spp. honey to tuna. More individuals of the subordinate species were recorded in the territory of F. polyctena than of L. fuliginosus, although conflicts with this territorial species were also recorded. During the three years of the study almost no overlaps in the territories of the two territorial species were recorded, and there were mostly minor shifts in the boundaries of the territories. Differences between the two territorial species in their use of space and competitive effects ensured their coexistence at this particular site in Finland. |
Demography of adults of the Marsh fritillary butterfly, Euphydryas aurinia (Lepidoptera: Nymphalidae) in the Czech Republic: Patterns across sites and seasonsKamil ZIMMERMANN, Pavla BLAZKOVA, Oldrich CIZEK, Zdenek FRIC, Vladimir HULA, Pavel KEPKA, David NOVOTNY, Irena SLAMOVA, Martin KONVICKAEur. J. Entomol. 108 (2): 243-254, 2011 | DOI: 10.14411/eje.2011.033 The Marsh fritillary (Euphydryas aurinia) (Lepidoptera: Nymphalidae) has declined across Europe, including the Czech Republic. Current conservation strategies rely on prevention of habitat loss and degradation, and increase in habitat quality and connectivity via promoting traditional grassland management. The population structure and adult demography parameters of a single population was investigated for eight years (single system), and of all the known Czech populations (multiple populations) for a single year, using mark-recapture. There was substantial variation in the patterns of adult demography, both among years in the single system and among the multiple populations in a single year. In the single system, the date of the first flight of an adult varied by 18 days over the 8 years and total annual numbers varied with a coefficient of variation of 0.40 (females fluctuating more than males). The average density was ca 80 adults/ha. The population size displayed density-dependence, i.e. decreased following years with high adult numbers, with an equilibrium density of 90 individuals/ha. The average density of the multiple populations was ca 120 individuals/ha. The estimated total population for the Czech Republic was 25,000 individuals (17,000 males / 8,000 females) in 2007, which does not indicate an imminent threat of extinction. The regional persistence of E. aurinia is likely to depend on re-colonisation of temporarily vacant sites by dispersing individuals, facilitated by local shifts in adult flight phenology to that better adapted to local conditions. |
Revision of the genus Figura (Coleoptera: Coccinellidae) with descriptions of new speciesKarol SZAWARYNEur. J. Entomol. 111 (1): 105-119, 2014 | DOI: 10.14411/eje.2014.012 The African genus Figura Ukrainsky, 2006 is revised. A detailed redescription of its morphology is presented. Three new species are described, F. bitalensis sp. n., F. lineata sp. n. and F. ruwenzorica sp. n. All species are illustrated. A key to all species and a map showing the distribution of the genus Figura are provided. |
Prevalence of male-killer in a sympatric population of two sibling ladybird species, Harmonia yedoensis and Harmonia axyridis (Coleoptera: Coccinellidae)Suzuki NORIYUKI, Yuichi KAMEDA, Naoya OSAWAEur. J. Entomol. 111 (2): 307-311, 2014 | DOI: 10.14411/eje.2014.029 In predatory ladybirds male embryos in clutches of eggs infected with male-killing bacterial endosymbionts do not hatch and are consumed by female hatchlings. Moreover, it is predicted that infection with male-killing bacteria should be prevalent in a ladybird population if the fitness advantage to female ladybirds due to the resulting reallocation of resources is high. We compared male-killer bacterial prevalence in two sibling species of the ladybird genus Harmonia that use different host ranges. Harmonia yedoensis feeds mostly on the highly elusive pine aphid and its hatchlings can greatly enhance their ability to capture prey and thus their survival by consuming un-hatched eggs in the clutch. In contrast, Harmonia axyridis feeds on a wide range of prey and consumption of un-hatched eggs by the hatchlings does not necessarily increase their foraging success. In the study area where these two species of ladybird occur sympatrically 14 of the 22 females of H. yedoensis (64%) laid clutches of eggs of which approximately only a half hatched and did not produce male offspring, whereas only one of 12 of the females of H. axyridis (8%) exhibited symptoms indicating infection with male-killing bacteria. In the H. yedoensis that exhibited symptoms of being infected with male-killing bacteria, the total allocation of resources to each hatchling, which was provided by laying larger eggs and eating the un-hatched eggs in the clutch, was considerable. These results suggest that the difference in the prevalence of infection with male-killing bacteria in these two species of ladybird may reflect differences in the quality of their prey and their foraging behaviour. |
Imperfections in perfect architecture: The orb web of spidersAlain PASQUET, Julia MARCHAL, Mylène ANOTAUX, Raymond LEBORGNEEur. J. Entomol. 110 (3): 493-500, 2013 | DOI: 10.14411/eje.2013.065 Among animal constructions, the orb webs of spiders are perfect geometrical architectural models. Webs are constructed by means of a succession of behaviours, which are often considered as instinctive and stereotyped. Anomalies in web structure are considered to be a consequence of variability in behaviour. In order to assess the variability in web structure, the spider Zygiella x-notata was allowed to build webs in the laboratory under standardized conditions. Webs (n = 127) were examined for anomalies, which were defined as modifications in the geometrical structure. Ten anomalies in the structure of webs produced by females, aged from 16 to 21 days after their adult moult, are described. The frequency of anomalies per web varies from 5 to 98. A very low percentage of the spiral elements of a web (less than 5%) were affected. Anomalies in the radii were less numerous (mean = 3 ± 3) than those in the sticky spiral (mean = 21 ± 11). Anomalies in the sticky spiral were different and more frequent in the peripheral than central parts of the webs. They were also relatively more numerous in the upper than in the lower part of the webs. Total number of anomalies was positively correlated with particular web characteristics (capture area, length of capture thread, width of the lower part of the web and mean distance between two spiral turns in the lower part) but not to the physical characteristics of the spiders (mass and size). Our results indicate that the orb webs of spiders, which are considered to be perfect geometrical structures, include anomalies mainly in the structure of the sticky spiral. These anomalies were the result of variability in behaviour during web building. In conclusion, their identification and description enable one to use them in spider webs as an index of behavioural variability. |
The plant bug genus Psallus (Heteropera: Miridae) in the Korean Peninsula with descriptions of three new speciesRam Keshari DUWAL, Tomohide YASUNAGA, Sunghoon JUNG, Seunghwan LEEEur. J. Entomol. 109 (4): 603-632, 2012 | DOI: 10.14411/eje.2012.074 There are twenty-six species of the genus Psallus Fieber, 1858 (Phylinae: Phylini) documented in the Korean Peninsula. Three new species are described: Psallus cheongtaensis sp. n., P. ernsti sp. n. and P. suwonanus sp. n., and four species are reported from Korea for the first time: Psallus cinnabarinus Kerzhner, 1979, P. flavescens Kerzhner, 1988, P. loginovae Kerzhner, 1988, and P. roseoguttatus Yasunaga & Vinokurov, 2000. The genitalic structures of females and males are described and figured for most treated species. A key is provided for identifying all the Korean species. |
Effects of cold acclimation, cooling rate and heat stress on cold tolerance of the potato tuber moth Phthorimaea operculella (Lepidoptera: Gelechiidae)Chamran HEMMATI, Saeid MOHARRAMIPOUR*, Ali ASGHAR TALEBIEur. J. Entomol. 111 (4): 487-494, 2014 | DOI: 10.14411/eje.2014.063 This study was carried out to investigate the effects of cold acclimation, cooling rate and heat stress on supercooling capacity and cold hardiness of the potato tuber moth (PTM), Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae). Supercooling points (SCP) of first and last instar larvae, prepupae and pupae were -21.8, -16.9, -18.9 and -18.0°C, respectively. Cold acclimation (1-week at 0 and 5°C) did not affect SCPs of acclimated last instar larvae, prepupae and pupae. LT50s (lower lethal temperature for 50% mortality) for first and last instar larvae, prepupae and pupae were -15.5, -12.4, -17.9 and -16.0°C, respectively. Cold acclimation resulted in a significant decrease in mortality of all developmental stages. In addition, the mortality rates of the different developmental stages decreased with decrease in cooling rate. In addition, heat hardening (kept at 40°C for 2 h) significantly reduced mortality of all developmental stages exposed to LT50 conditions, suggesting that heat hardening also affects cold tolerance. Results indicate that none of the stages could tolerate subzero temperatures below their SCPs, indicating that this species might be a chill tolerant insect. These adaptive responses may allow PTM to enhance its cold tolerance and colonize cold regions. |
Relationships between locomotor activity, oxidative damage and life span in males and females of the linden bug, Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)Marcela BURICOVA, Magdalena HODKOVAEur. J. Entomol. 110 (3): 443-449, 2013 | DOI: 10.14411/eje.2013.059 In this study we addressed a question of whether experimental manipulations that increase life span also reduce physical activity and molecular oxidative damage. We used three phenotypes of male and female Pyrrhocoris apterus that survive for different lengths of time, diapausing insects, reproductive insects and insects from which the corpus allatum, the source of juvenile hormone, was surgically removed. Protein carbonyl content of the thoracic muscles was used as an index of molecular oxidative modification. Diapause or ablation of the corpus allatum (allatectomy) was associated with an extended life span of both sexes, but only those individuals that were in diapause were less active. The carbonyl content, both relative (per protein unit) and absolute (per thorax) increased with age in reproductive insects of both sexes. However, the associations between the carbonyl content and diapause and allatectomy differed in males and females. In males, the carbonyl content was not associated with either diapause or allatectomy. There was no age-related increase in the relative and absolute carbonyl levels in diapausing females, while only the increase in the relative carbonyl level was absent in allectomized females. Overall, the results indicate that both allatectomy and diapause prolonged life span, but had different and sex-specific effects on locomotor activity and carbonyl content. Only the extension of the life span of diapausing females was correlated with both reduced locomotor activity and reduced carbonyl content. |
Gas exchange patterns in Platynus assimilis (Coleoptera: Carabidae): Respiratory failure induced by a pyrethroidIrja KIVIMÄGI, Aare KUUSIK, Angela PLOOMI, Luule METSPALU, Katrin JÕGAR, Ingrid H. WILLIAMS, Ivar SIBUL, Külli HIIESAAR, Anne LUIK, Marika MÄNDEur. J. Entomol. 110 (1): 47-54, 2013 | DOI: 10.14411/eje.2013.006 Discontinuous gas exchange (DGE) is the main (23 individuals) breathing mode in resting adult Platynus assimilis. Few of the beetles tested (13 individuals) displayed a pattern of cyclic gas exchange or CGE. The burst of CO2 release in DGE and CGE was always accompanied by abdominal pumping (active ventilation or V). Seven individuals displayed a pattern of continuous respiration, characterized by regular abdominal pumping. Resting metabolic rate (RMR) in continuously breathing beetles was higher than in those using DGE and CGE. After treatment with sub-lethal doses of alpha-cypermethrin DGE ceased. Treated beetles were characterized by continuous pumping and almost regular periods of activity. RMR increased significantly after treatment with a pyrethroid. |
Analysis of the number of sensilla on the labrum and the diet of grasshoppers belonging to the family Pamphagidae (Orthoptera)Naima BENKENANA, Abboud HARRAT, Daniel PETITEur. J. Entomol. 110 (2): 355-364, 2013 | DOI: 10.14411/eje.2013.097 We studied the diet of 10 species of grasshopper belonging to the family Pamphagidae over a period of 3 years at 6 localities in North Eastern Algeria. The species of plants consumed by the grasshoppers was determined by comparing slide mounted specimens of the pieces of plant epidermis in their faeces with those in a reference collection of identified plants collected from the same localities. The percentages of occurrence of the different species of plants in the faeces of the grasshoppers were not related to the abundance of the plants at the sites studied. All the grasshoppers were polyphagous but differed in the percentage of Poaceae in their diets. The diet of Tmethis and Ocneridia contained a higher percentage of Poaceae than the other species and are considered to be ambivores. The three species in the Pamphagus gr. djelfensis complex differ in their diets but all tend to avoid consuming Poaceae and are categorized as forbivores. We also compared the frequency of occurrence of Fabaceae in the faeces and in the field and O. volxemii is the only species that avoided consuming this plant family. The number of sensilla on the labrum was also studied in both sexes of each species. Once one corrects for differences in the size of the labrum, the forbivores have higher numbers of sensilla in groups A1, A2 and A3 (but not A10) than the ambivores. The numbers of sensilla in the A10 group on the labrum of species of Pamphagidae is greater than on that of species of Acrididae, which are mainly graminivores and adapted to semi-arid conditions. |
More evidence for an admixture of the Hyles euphorbiae complex's main lineages in Mediterranean Europe (Lepidoptera: Sphingidae)Michael B. MENDE, Anna K. HUNDSDOERFEREur. J. Entomol. 111 (4): 584-587, 2014 | DOI: 10.14411/eje.2014.065 The populations of the Hyles euphorbiae complex on Crete and the Dodecanese Islands have been described as an endemic species, Hyles "cretica". Alternatively, they are thought to be of hybrid origin from the complex's two main lineages, the European H. euphorbiae and African H. tithymali, because of their intermediate morphology. That they belong to a discrete taxon is supported by the fact that all the recent samples analyzed belong to an endemic mitochondrial haplotype cluster; however, this cluster is so close to the tithymali cluster that it might also be regarded as a sublineage of H. tithymali. Similarly, southern Italy is currently dominated by another distinct tithymali-related cluster, named "italica". However, sequencing of historic museum specimens, which were collected in Italy during the past century, revealed that mitochondrial haplotypes of H. euphorbiae were once present throughout the entire range of "italica" thus contradicting a long-term isolated evolution of a southern Italian refugial entity. In the present study we likewise sequenced the few available historic specimens from the Aegean Islands and also found a specimen from Crete which belonged to the euphorbiae cluster. In conclusion, southern Italian and southern Aegean populations both appear to be dynamic hybrid mixtures of the European H. euphorbiae and African H. tithymali, rather than separately evolved taxa. |
Specialized feeding of Euconnus pubicollis (Coleoptera: Staphylinidae: Scydmaeninae) on oribatid mites: Prey preferences and hunting behaviourPawe³ JA£OSZYÑSKI, Ziemowit OLSZANOWSKIEur. J. Entomol. 110 (2): 339-353, 2013 | DOI: 10.14411/eje.2013.047 Prey preferences and feeding-related behaviour of a Central European species of Scydmaeninae, Euconnus pubicollis, were studied under laboratory conditions. Results of prey choice experiments involving 50 species of mites belonging to 24 families of Oribatida and one family of Uropodina demonstrated that beetles feed mostly on ptyctimous Phthiracaridae (over 90% of prey) and only occasionally on Achipteriidae, Chamobatidae, Steganacaridae, Oribatellidae, Ceratozetidae, Euphthiracaridae and Galumnidae. The average number of mites consumed per beetle per day was 0.27 ± 0.07, and the entire feeding process took 2.15-33.7 h and showed a clear linear relationship with prey body length. Observations revealed a previously unknown mechanism for capturing prey in Scydmaeninae in which a droplet of liquid that exudes from the mouth onto the dorsal surface of the predator's mouthparts adheres to the mite's cuticle. Morphological adaptations associated with this strategy include the flattened distal parts of the maxillae, whereas the mandibles play a minor role in capturing prey. Mechanisms for overcoming the prey's defences depended on the body form of the mite. When attacking oribatids that adopt the ptychoid defence (encapsulation) Euconnus opened the prodorsum and pressed the anal and genital plates deeply into the idiosoma, whereas it fed on all other mites by entering their bodies through small gnathosomal or/and genital openings, after breaking off mouthparts or/and genital plates. The preferential feeding of a specialized and locally abundant ant-like stone beetle on one family of Oribatida, documented here for the first time, has implications for the population dynamics of the prey and raises questions about predator-prey co-evolution and costs of an unusually prolonged period spent feeding when at risk from competition and attack by larger predators, typical of the habitats where Scydmaeninae occur. |
Evaluation of criteria for species delimitation of bagworm moths (Lepidoptera: Psychidae)Veronica CHEVASCO, Jelmer A. ELZINGA, Johanna MAPPES, Alessandro GRAPPUTOEur. J. Entomol. 111 (1): 121-136, 2014 | DOI: 10.14411/eje.2014.013 Accurate identification of species is fundamental for biological research and necessary for species conservation. DNA barcoding is particularly useful when identification using morphological characteristics is laborious and/or unreliable. However, barcodes for species are dependent on the availability of reference sequences from correctly identified specimens. The traditional use of morphology to delimit the species boundaries of Finnish bagworm moths (Lepidoptera: Psychidae: Naryciinae: Dahliciini) is controversial because there is overlap in their morphological characteristics. In addition, there are no suitable molecular markers. We verified the delimitation of seven out of eight previously described taxa, by using the currently standardized COI barcode and phylogenetic inference based on fragments of mitochondrial (COI) and nuclear genes (MDH). Moreover, we compared the results of molecular methods with the outcome of geometric morphometrics. Based on molecular identification, our findings indicate that there are five sexual species (Dahlica and Siederia spp.) and two parthenogenetic species (D. fennicella and D. triquetrella) in Finland. We suggest that molecular methods, together with geometric morphometrics of male genitalia are an effective way of delimiting species of bagworm moths. |
Bioluminescent assay for evaluating antimicrobial activity in insect haemolymphLibor VOJTEK, Pavel DOBE©, Ender BÜYÜKGÜZEL, Janne ATOSUO, Pavel HYR©LEur. J. Entomol. 111 (3): 335-340, 2014 | DOI: 10.14411/eje.2014.045 We describe an antibacterial assay based on bioluminescence of two Gram negative bacteria, Photorhabdus luminescens and transformed Escherichia coli, which can be used as a real-time measurement of antibacterial activity in insect haemolymph. This method is based on the production of the bioluminescence signal depending on the viability of bacterial cells. We observed a significant rapid dose-dependent decrease in bioluminescence using both bacterial species, and Bombyx mori or Galleria mellonella haemolymph, which was confirmed by the decrease in bacterial viability determined by plating. The humoral origin of the antibacterial activity observed in whole haemolymph was confirmed for haemolymph plasma without haemocytes. Antibacterial activity directed against Gram negative bacteria was recorded in unaffected insect larvae as well as after septic injury; increased antibacterial activity of haemolymph was detected in the latter case confirming the inducibility of antimicrobial agents. We think it is likely that this method could be widely used for determining antibacterial activity in insects and other invertebrates. |
Araneae communities associated with the canopies of chestnut trees in the northeastern part of Portugal: The influence of soil management practicesJacinto BENHADI-MARIN, José Alberto PEREIRA, José-Antonio BARRIENTOS, Albino BENTO, Sónia A.P. SANTOSEur. J. Entomol. 110 (3): 501-508, 2013 | DOI: 10.14411/eje.2013.066 Chestnut (Castanea sativa Mill.) is one of the economically more important trees in the north of Portugal. Spiders, as generalist predators, are potential controlling agents of pests, yet the composition of the community of spiders associated with this crop is only poorly known. The objective of this study was to determine the spider communities in the canopies of chestnut trees subject to three different soil management practices in northeastern Portugal. Three chestnut groves each subject to a different agricultural practice (grazed, tilled or untilled) were studied in 2008 and 2009. The Araneae communities were sampled by beating the branches and the individuals collected were identified to family and species when possible. To investigate the structure of the spider community in each grove the abundance and family richness of spiders were calculated and compared between managements. In total, 4172 spiders were collected and, in both years, the three most abundant families were Araneidae, Philodromidae and Linyphiidae. In 2008, there was a greater abundance of spiders in the grazed, followed by the tilled and untilled groves, but no significant differences among groves. However, in 2009 there was a greater abundance of spiders in the tilled grove, followed by grazed and untilled groves and the differences between the untilled and the other two groves were significant. Araniella, Oxyopes and Anyphaena were the most abundant genera in the three groves. This study showed that soil management may influence the diversity of spiders, but the effects were weak and not consistent between years. The reduction or absence of a suitable habitat for spiders under the trees in the tilled treatment might have resulted in the spiders migrating up into the canopy. However, based on the weak effects on spider abundance recorded and its potentially adverse effects on soils, tillage is not recommended for managing the incidence of pests in chestnut groves. |
Life-history of the parthenogenetic oonopid spider, Triaeris stenaspis (Araneae: Oonopidae)Stanislav KORENKO, Jakub ©MERDA, Stano PEKÁREur. J. Entomol. 106 (2): 217-223, 2009 | DOI: 10.14411/eje.2009.028 Selected life-history traits of an oonopid spider, Triaeris stenaspis Simon, which has been introduced into greenhouses in Europe, were investigated. Spiders were reared in the laboratory under constant physical and dietary conditions, and followed from egg to death. The spiders passed through 3 juvenile instars, each lasting approximately a month. The adult stage lasted on average 6 months, which is 54% of the entire life cycle. The mortality in each juvenile instar was similar. Five morphological characters were recorded for each instar, which provided a reliable means of identifying the developmental stages. All spiders developed into females and although kept isolated they laid fertile eggs, which indicates thelytokous parthenogenesis. Eggs were always enclosed in a disc-shaped egg-sac, each containing 2 eggs. Total fecundity was on average 27 eggs and rate of laying eggs decreased with age. Fecundity was positively correlated with adult longevity. Fertility was rather low, approximately 59%. It was negatively correlated with fecundity but not related to longevity. Low fertility appears to be the only cost of parthenogenetic reproduction. There was considerable genotypic variation in all traits studied compared to that in sexually reproducing spiders. There were no apparent maternal effects on all the traits studied. Using molecular methods proved that parthenogenesis in T. stenaspis is not induced by the endosymbiotic bacteria, Wolbachia sp. or Cardinium sp. |
Some ethological aspects of the trophobiotic interrelations between ants (Hymenoptera: Formicidae) and larvae of the sawfly Blasticotoma filiceti (Hymenoptera: Blasticotomidae)Tatiana A. NOVGORODOVA, Olga B. BIRYUKOVAEur. J. Entomol. 108 (1): 47-52, 2011 | DOI: 10.14411/eje.2011.006 Some ethological aspects of the interrelations between ants and the larvae of Blasticotoma filiceti Klug, 1834 were investigated in the Altai Republic and Novosibirsk Region in 2006-2008. The interactions of ants with the larvae of this sawfly are determined by the concealed way of life style of B. filiceti. The majority of the ant-sawfly encounters occurred near holes in fern fronds at the moment when larvae excreted liquid or left their tunnels before descending to the soil prior to overwintering. Sawfly larvae visited by more aggressive ants, such as Formica s. str., leave the fern fronds slowly, which enables them to avoid inciting attacks by ants. The behaviour of the ants while collecting the larval excretion is similar to their behaviour at sugar troughs. The organisation of the collecting larval excreta by ants was investigated in detail in the cases of Formica polyctena Förster, 1850 and Myrmica rubra Linnaeus, 1758. The individual fern plants with sawfly larvae are attended by relatively constant groups of foragers in both cases. However, the highly social red wood ants interact with sawfly larvae in a more complex way. While the working groups of M. rubra tending sawfly larvae consist only of non-aggressive "unspecialized" foragers, those of F. polyctena include also a few "on duty" ants that protect the trophobionts, at least from the other ants. |
Comparative analysis of maternal and grand-maternal photoperiodic responses of Trichogramma species (Hymenoptera: Trichogrammatidae)Natalia D. VOINOVICH, Nina P. VAGHINA, Sergey Ya. REZNIKEur. J. Entomol. 110 (3): 451-460, 2013 | DOI: 10.14411/eje.2013.060 Maternal and grand-maternal photoperiodic responses of Trichogramma buesi, T. embryophagum, T. evanescens, T. piceum, T. principium, and T. telengai were investigated in laboratory conditions. During the experiment, grand-maternal and maternal generations developed at 20°C and one of the 4 photoperiodic regimes: L : D = 12 : 12, 14 : 10, 16 : 8, and 18 : 6 (in total, 16 combinations) while the progeny developed at L : D = 12 : 12 and one of the 3 thermal regimes: 13, 14, and 15°C. The proportion of diapausing individuals in the progeny of all the studied species was significantly dependent on the direct influence of temperature and on the maternal photoperiodic response. The influence of the photoperiodic conditions during development of the grand-maternal generation was statistically significant in 5 of the 6 studied species, being relatively weak in T. embryophagum and T. telengai, whose geographical ranges extend up to north-western regions of Europe (possibly, these wasps enter diapause so early that the grand-mothers of the diapausing generation develop under long day conditions). Comparative analysis showed that the thresholds of the maternal and grand-maternal photoperiodic responses coincided or almost coincided. The grand-maternal effect was stronger in the progeny of maternal females which developed under short day conditions than in those that developed under long day conditions. This pattern of interaction probably synchronizes the life cycle with seasonal changes because diapause is induced under decreasing day length and thus mothers of diapausing individuals develop at shorter daylength than do grand-mothers. We conclude that the grand-maternal and the maternal effects on Trichogramma progeny diapause are based on one and the same photoperiodic response. In nature, the grand-maternal effect increases the proportion of diapausing individuals in the progeny of females which have developed under short day conditions during two generations, thus achieving a "cumulative" photoperiodic effect. |
Response of Lymantria dispar (Lepidoptera: Lymantriidae) larvae from differently adapted populations to allelochemical stress: Effects of tannic acidMarija MRDAKOVIÆ, Vesna PERIÆ MATARUGA, Larisa ILIJIN, Milena VLAHOVIÆ, Milena JANKOVIÆ TOMANIÆ, Dejan MIRÈIÆ, Jelica LAZAREVIÆEur. J. Entomol. 110 (1): 55-63, 2013 | DOI: 10.14411/eje.2013.007 The effects of tannic acid on mean values and genetic variation in fitness-related traits (mass, relative growth rate) and specific activities of digestive enzymes (total proteases, a-glucosidase and lipase), and genetic variation in their plasticity, were investigated in fifth instar larvae of Lymantria dispar L. (Lepidoptera: Lymantriidae) originating from two populations with different host use histories (oak and locust-tree). The two populations did not differentiate with respect to fitness-related traits, i.e. adverse effects of tannic acid were similar in both populations. However, Robinia larvae, which originated from the locust-tree forest, were characterized by higher total protease and lipase activity and lower a-glucosidase activity than Quercus larvae, which originated from the oak forest. Higher plasticity of lipase and lower plasticity of a-glucosidase in response to tannic acid were also recorded. Quantitative genetic analysis revealed mostly significant expression of genetic variation in the examined traits and trait plasticity, suggesting the potential for evolution of adaptive plastic responses to new environmental conditions and presence of a stressor. The genetic correlations observed between the environments significantly differed from "one", which indicates there are no constraints on the evolution of trait plasticity. |
Parasitism and migration in southern Palaearctic populations of the painted lady butterfly, Vanessa cardui (Lepidoptera: Nymphalidae)Constantí STEFANESCU, Richard R. ASKEW, Jordi CORBERA, Mark R. SHAWEur. J. Entomol. 109 (1): 85-94, 2012 | DOI: 10.14411/eje.2012.011 The painted lady butterfly (Vanessa cardui) (Lepidoptera: Nymphalidae: Nymphalinae) is well known for its seasonal long-distance migrations and for its dramatic population fluctuations between years. Although parasitism has occasionally been noted as an important mortality factor for this butterfly, no comprehensive study has quantified and compared its parasitoid complexes in different geographical areas or seasons. In 2009, a year when this butterfly was extraordinarily abundant in the western Palaearctic, we assessed the spatial and temporal variation in larval parasitism in central Morocco (late winter and autumn) and north-east Spain (spring and late summer). The primary parasitoids in the complexes comprised a few relatively specialized koinobionts that are a regular and important mortality factor in the host populations. However, there was a strong seasonal variation in the level of parasitism. In Spain percentage parasitism was more than four times higher in late summer than in spring (77.3% vs. 18%), while in Morocco it was five times higher by the end of winter than in the autumn (66.2% vs. 13.2%). In both regions the build up of parasitoid populations occurred after V. cardui had bred in the same general area over successive generations, and this may represent a selective force favouring seasonal migration to enemy-free space. |
Diapause and post-diapause quiescence demonstrated in overwintering Harmonia axyridis (Coleoptera: Coccinellidae) in northwestern EuropeC. Lidwien RAAK-VAN DEN BERG, Peter W. DE JONG, Lia HEMERIK, Joop C. VAN LENTERENEur. J. Entomol. 110 (4): 585-591, 2013 The Asian ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is regarded as an invasive species in many parts of the world. In a previous study we hypothesised that H. axyridis enters diapause at the end of October and then shifts to a quiescent state in December in northwestern Europe. In the present study we test this idea of a short, early period of diapause by sampling beetles from their hibernation sites immediately after their migratory flights in October, subsequently keeping them in outdoor cages, and then, after certain time-intervals, measuring the pre-oviposition time under optimal egg-laying laboratory conditions at 25°C. We did this at both short (12L) and long (16L) photoperiods, since a photoperiodic response is an indicator of true diapause, rather than quiescence. A significant, albeit small, difference in pre-oviposition period between the two photoperiods, which disappears in December, corroborates our earlier hypothesis that the ladybirds are in a state of diapause until mid-December. Compared with that of native ladybirds the diapause of H. axyridis generally is relatively short and weak; moreover, it appears to have become shorter over the last decade. This flexibility in diapausing behaviour may be an important factor that contributes to the invasive success of H. axyridis. |
Characterization of ten polymorphic microsatellite markers for an endangered butterfly Argynnis niobe and their cross-species utility in the closely related species A. adippe (Lepidoptera: Nymphalidae)Jan ZIMA Jr., Dan LE©TINA, Martin KONVIÈKAEur. J. Entomol. 110 (2): 383-387, 2013 | DOI: 10.14411/eje.2013.098 The Niobe Fritillary, Argynnis niobe, is a habitat specialist and as a consequence is highly endangered in contemporary Europe. To investigate its genetic diversity and population structure, 10 polymorphic microsatellite loci were developed and characterized, using a recently developed pyrosequencing method. The number of alleles per locus ranged from 2 to 21, and the observed and expected heterozygosities varied from 0.17 to 0.53 and from 0.24 to 0.92, respectively. These loci were also successfully used to study the genetic diversity of a closely related species, the High Brown Fritillary, Argynnis adippe, and will be used in future population structure studies of both these species. |
A karyological study of four European species of Roncus (Pseudoscorpiones: Neobisiidae)Franti¹ek ©«ÁHLAVSKÝ, Jana CHRISTOPHORYOVÁ, Hans HENDERICKXEur. J. Entomol. 110 (3): 393-399, 2013 | DOI: 10.14411/eje.2013.052 We present the results of the first study on the karyotypes of four European species of Roncus: Roncus alpinus L. Koch, 1873, Roncus lubricus L. Koch, 1873, Roncus transsilvanicus Beier, 1928 and Roncus sp. The diploid number was 2n = 23 in Roncus sp., 2n = 43 in R. alpinus and R. transsilvanicus and 2n = 45 in R. lubricus. Telocentric autosomes predominate in species with a high chromosome number and metacentric autosomes in Roncus sp. We assume that the ancestral situation for this genus is a high number of chromosomes. A low number of chromosomes is very likely a consequence of centric fusions, which have possibly played a very important role in karyotype evolution in the genus Roncus. All the species analyzed have the X0 sex chromosome system. The X chromosome is metacentric and is the smallest element in the karyotypes of all the species analyzed. |
The central-marginal hypothesis in acridid Orthoptera: A critique of Colombo's (2012) articleClaudio J. BIDAU, Dardo A. MARTÍEur. J. Entomol. 110 (2): 181-185, 2013 | DOI: 10.14411/eje.2013.028 We discuss and criticise the contention of Colombo (2012) that the central-marginal model does not apply to three species of chromosomally polymorphic acridid grasshoppers, and that chromosomal clines in these species are a consequence of temperature gradients. We also discuss Colombo's interpretation of our own results on the South American melanopline grasshopper, Dichroplus pratensis Bruner. |
Abundance and host associations of parasitoids attacking frugivorous drosophilids on Iriomote-jima, a subtropical island of JapanBiljana NOVKOVIÆ, Ayako OIKAWA, Yusuke MURATA, Hideyuki MITSUI, Masahito T. KIMURAEur. J. Entomol. 109 (4): 517-526, 2012 | DOI: 10.14411/eje.2012.065 To understand the factors governing the diversity, abundance and host associations of parasitoids attacking frugivorous drosophilid flies on Iriomote-jima, a subtropical island of Japan, we monitored parasitism on several occasions over the period 2003-2009. Fifteen drosophilid and 12 parasitoid species were recorded. Three species of Drosophila, D. bipectinata, D. albomicans and D. takahashii, bred abundantly in banana baits, though their abundance varied between years and seasons. Frequent parasitoid species were Asobara japonica, A. pleuralis (Braconidae), Leptopilina ryukyuensis and L. pacifica (Figitidae). L. victoriae was recorded only in December 2003. In addition, host acceptance and host suitability of the four most frequently recorded parasitoid species were studied in the laboratory. Most parasitoid and drosophilid species showed species-specific associations with more than one antagonist species, suggesting that they have been subjected to complex coevolutionary interactions. In addition, host range of most of the parasitoid species included one of the three major Drosophila species, suggesting that the abundance of potential hosts is one of the factors determining the evolution of parasitoid host use. |
Laboratory studies on intraguild predation and cannibalism among coccinellid larvae (Coleoptera: Coccinellidae)Gabriele RONDONI, Andrea ONOFRI, Carlo RICCIEur. J. Entomol. 109 (3): 353-362, 2012 Intraguild predation (IGP) and cannibalism occur in the field and could affect the dominance structure of guilds of coccinellid species. The exotic biological control agent Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is now well established in most areas of Northern and Central Italy, but it is unclear what effect this species could have on native dominant and non-dominant coccinellids with which it co-occurs. In order to predict the trophic interactions in coccinellid guilds and the likely effect of H. axyridis, the incidence of IGP and cannibalism among the following six species were evaluated under laboratory conditions: H. axyridis, three native dominant species, Adalia bipunctata (L.), Oenopia conglobata (L.) and Coccinella septempunctata L. and two native non-dominant species, Platynaspis luteorubra (Goeze) and Scymnus apetzi (Mulsant). Unfed and fed fourth instar larvae of the above species were paired in an experimental arena and the incidence of predation recorded over a period of 24 h. In absence of aphids, the survival probabilities (SP) of A. bipunctata and O. conglobata were lowest when paired with either C. septempunctata or H. axyridis (< 0.20 SP after 24 h). The SP of C. septempunctata was similar if paired with either a conspecific larva or H. axyridis (< 0.34 SP after 24 h) and that of H. axyridis was reduced similarly if paired with either a conspecific larva or C. septempunctata (> 0.71 SP after 24 h). The SP of P. luteorubra was lower when paired with A. bipunctata and C. septempunctata (< 0.07 SP after 24 h) than with other species and that of S. apetzi was greatly reduced when paired with all the dominant and exotic species (< 0.27 SP after 24h). In presence of aphids no predatory events occurred in most combinations. H. axyridis acted as a strong predator of native dominant and non-dominant coccinellids when the aphids are scarce. We did not find any evidence, however, that the incidence of IGP among exotic and native species is higher than either IGP or cannibalism in native species. The likelihood of IGP occurring in the field is discussed. |
Forest moth assemblages as indicators of biodiversity and environmental quality in a temperate deciduous forestJeong-Seop AN, Sei-Woong CHOIEur. J. Entomol. 110 (3): 509-517, 2013 | DOI: 10.14411/eje.2013.067 The aim of the present study was to find groups of moths suitable for estimating changes in the abundance and richness of local and regional biodiversity in a temperate forest. We captured macro-moths from May to October over a 5-year period (2005-2009) at various sites in Mt. Jirisan National Park (JNP) in southern Korea. Six taxa were selected based on a strong correlation between the number of species in these taxa and total number of species of large moths: Ennominae (Enn), Arctiinae (Arc), Hermininae (Her), Notodontidae (Not), Drepanidae (Dre) and Ophiderinae (Oph). Of these, combinations of four groups were found to have the best predictive capability. We determined whether these indicator groups could be used to reveal mean differences in species abundance according to spatial (forest type, altitude) and temporal variables (monsoon season) since moth composition and abundances were closely related with these variables. The mean differences in the groups of moths in the two types of forest (Arc, Dre, Enn, Not), two altitudes (Dre, Enn, Her, Oph) and two seasons (Dre, Enn, Oph) were significant. Overall, it was revealed that a set of four groups, including two taxa (Dre and Enn), could be used to show differences in local and regional biodiversity of moths in southern Korean temperate forest. |



