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Results 721 to 750 of 1442:

Vertical stratification and microhabitat selection by the Great Capricorn Beetle (Cerambyx cerdo) (Coleoptera: Cerambycidae) in open-grown, veteran oaks

Jan ALBERT, Michal PLATEK, Lukas CIZEK

Eur. J. Entomol. 109 (4): 553-559, 2012 | DOI: 10.14411/eje.2012.069

The great capricorn beetle or Cerambyx longicorn (Cerambyx cerdo, Linnaeus, 1758) is an internationally protected umbrella species representing the highly diverse and endangered fauna associated with senescent oaks. For the conservation and monitoring of populations of C. cerdo it is important to have a good knowledge of its microhabitat requirements. We investigated determinants and patterns of C. cerdo distribution within individual old, open-grown oaks. Trees inhabited by this species were climbed, and the number of exit holes and environmental variables recorded at two sites in the Czech Republic. Distribution of exit holes in relation to height above the ground, trunk shading by branches, orientation in terms of the four cardinal directions, diameter, surface and volume of inhabited tree parts were investigated. This study revealed that the number of exit holes in the trunks of large open-grown oaks was positively associated with the diameter of the trunk and openness and negatively with height above the ground, and the effects of diameter and openness changed with height. The number of exit holes in the surface of a trunk was also associated with the cardinal orientation of the surface. Approximately half of both C. cerdo populations studied developed less than 4 m and approximately a third less than 2 m above the ground. This indicates that most C. cerdo develop near the ground. Active management that prevents canopy closure is thus crucial for the survival of C. cerdo and searching for exit holes is an effective method of detecting sites inhabited by this species.

Temporal variation in elytral colour polymorphism in Hippodamia variegata (Coleoptera: Coccinellidae)

Alois HONEK, Zdenka MARTINKOVA, Pavel SASKA, Anthony F.G. DIXON

Eur. J. Entomol. 109 (3): 389-394, 2012

Lady beetles (Coleoptera: Coccinellidae) are a classical group for studying the mechanisms that determine local and temporal trends in colour polymorphism. Here we report long term trends in variation in the percentage of different morphs in a population of Hippodamia variegata (Goeze) at ©túrovo, Slovakia (47°48´N, 18°43´E). The morphs differ in the number and location of the spots on their elytra. Beetles were sampled from stands of herbaceous plants using a standard method each year in August over a period of 74 years from 1937 to 2011. Twenty two morphs (out of 74 possible) were recorded in a total sample of 6,984 individuals. Four dominant morphs made up 90% of the total sample and varied in their annual frequency independently of one another. Frequency of "pale" morphs (0-3 spots per elytra), supposedly favoured by a warm climate, increased from 1981 to 2000s' during a period of climate warming, but only after a decrease that took place between 1937 and 1981, which did not parallel a change in climate. Moreover, the differences in the extent of the melanization of the elytral surface are too small to significantly affect thermoregulation in the different morphs. Therefore, the results presented do not provide unequivocal support for climate change determining the long term trends in the variation in the proportions of the different morphs.

Aphid-plant interactions affect the suitability of Myzus spp. as prey for the two spot ladybird, Adalia bipunctata (Coleoptera: Coccinellidae)

Mohammad A. JALALI, J.P. MICHAUD

Eur. J. Entomol. 109 (3): 345-352, 2012

A laboratory study was conducted to examine tritrophic effects on the suitability of the peach-potato aphid, Myzus persicae (Sulzer), and tobacco aphid, Myzus persicae nicotianae (Blackman & Eastop), as prey for the two spot ladybird, Adalia bipunctata (L.), when the aphids were reared on either sweet pepper or tobacco. Significant host plant-aphid interactions were evident for every component of development (juvenile survival, developmental time, adult mass at emergence) and reproduction (pre-oviposition period, fecundity, fertility). By almost all measures, the suitability of each aphid species was improved by rearing on its host plant of origin and diminished by rearing on the alternative host plant. The symmetry of the interactions are suggestive of both positive and negative host plant effects on aphid suitability as prey. Whereas M. p. nicotianae may be better able than M. persicae to detoxify the nicotine that is likely responsible for the reduced suitability of M. persicae when reared on tobacco, it appears to have lower nutritive value for A. bipunctata than M. persicae when reared on pepper. Thus, population parameters (R0, rm, l and DT) derived from performance data indicated that M. persicae reared on sweet pepper was the most suitable prey and that the same species reared on tobacco was the least suitable, with other host plant-aphid combinations intermediate.

The effect of temperature on the preimaginal development of the Jewel beetle, Coraebus florentinus (Coleoptera: Buprestidae)

Ana M. CÁRDENAS, Patricia GALLARDO

Eur. J. Entomol. 109 (1): 21-28, 2012 | DOI: 10.14411/eje.2012.004

Environmental degradation caused by climate change greatly affects the forest ecosystems of the Mediterranean region, in particular the sclerophyllous Quercus forests typical of central and southern Spain. An important pest that damages oak trees in this area is Coraebus florentinus (Herbst), a heliophilous and thermophilous insect whose survival could be favoured by the temperature increase associated with climate change. The main objective of this paper was to determine the effect of temperature on the duration and percentage survival of the preimaginal stage of C. florentinus and provide data for determining more precisely when to control for this pest by applying silvicultural techniques. The experiment included six treatments, with 25 branches infested with C. florentinus in each of the treatments, which were kept at different temperatures over the range 15-28°C. The results clearly support the hypothesis that higher temperatures affect the post-larval development of C. florentinus by increasing the percentage survival and shortening the developmental time. In fact, partial correlations confirm that the highest percentages of emergence and survival were recorded when the developmental times were shortest, which occurred at the highest temperatures used. Despite the clear influence of temperature on the development of the preimaginal stage of C. florentinus, additional trials are required to accurately determine future trends in C. florentinus populations. Accordingly, it is necessary to develop monitoring programs in zones affected by C. florentinus and to apply scheduled management techniques that ensure the control of this species.

Aproceros leucopoda (Hymenoptera: Argidae): An East Asian pest of elms (Ulmus spp.) invading Europe

Stephan M. BLANK, Hideho HARA, József MIKULÁS, György CSÓKA, Constantin CIORNEI, Raoul CONSTANTINEANU, Irinel CONSTANTINEANU, Ladislav ROLLER, Ewald ALTENHOFER, Tomasz HUFLEJT, Gábor VÉTEK

Eur. J. Entomol. 107 (3): 357-367, 2010 | DOI: 10.14411/eje.2010.045

An invasive sawfly Aproceros leucopoda Takeuchi, 1939, which originates from East Asia, has colonized elms (Ulmus spp.) in Austria, Hungary, Poland, Romania, Slovakia and the Ukraine, at least since 2003. In Europe, the larvae can completely defoliate native and non-native elm trees and may cause at least partial dieback. Field observations indicate that elms are infested independent of their age and site characteristics. The life cycle of A. leucopoda is described based on material reared in Hokkaido, Japan. Parthenogenetic reproduction, short life cycle of summer generations and the ability to produce four generations per year result in the production of numerous progeny. The evolution of a seasonal dimorphism in head morphology, a simple cocoon that is attached directly to the host plant and a short period spent in the cocoon stage during summer, are putative apomorphies shared by Aproceros Takeuchi, 1939 and Aprosthema Konow, 1899. These traits reduce developmental costs and contribute to the proliferation of A. leucopoda. No specialized parasitoid, that can effectively reduce outbreaks of this species, is known. It is likely that this pest will spread into central and south-western Europe. Further monitoring of A. leucopoda is required to assess future range extensions in Europe, its exacerbating effect on Dutch elm disease and to find a suitable biocontrol agent. Concise keys to imaginal and larval stages are presented that will facilitate the identification of A. leucopoda.

Present conservation status of red wood ants in north-western Belgium: Worse than previously, but not a lost cause

Wouter DEKONINCK, Frederik HENDRICKX, Patrick GROOTAERT, Jean-Pierre MAELFAIT

Eur. J. Entomol. 107 (2): 209-218, 2010 | DOI: 10.14411/eje.2010.028

The number of colonies of red wood ants (Formica rufa group) in the north western part of Belgium has declined by more than half over the past 20 years. In the study area of 20 × 50 km there are currently only 36 colonies of two species of red wood ants (Formica rufa and F. polyctena). Both species form both monodomous and polydomous colonies. Monodomous F. rufa colonies occur in large areas of open woodland dominated by Pinus sylvestris. The other three types of red wood ant (F. rufa polydomous, F. polyctena mono- and polydomous) occur in clearings or along the margins of small areas of deciduous or mixed woodland. The extinction of red wood ants cannot be attributed to a loss of their main habitat. Their decline in abundance, however, appears to be due to the deterioration in their habitat caused by several factors. Shading by overgrowing shrubs and the closure of the tree canopy, nearby intensive agriculture, urbanisation and use of the forest for recreation are the more important factors threatening and ultimately leading to the extinction of colonies. At poor quality sites there are no or very few nests of Serviformica ants, which initially serve as host ants and are necessary for recolonization by red wood ants. Thus, it is unlikely that these sites will be recolonized. To conserve red wood ants and maintain populations there is an urgent need to undertake certain measures, especially in areas outside nature reserves. For this there is a need to create clearings in the woodland, reduce shading due to overgrowing shrubs and closure of the tree canopy, and mitigate the effects of intensive agriculture, urbanisation and recreation. It is important that the effects of these measures should be monitored.

A novel association between Aphaenogaster subterranea (Hymenoptera: Formicidae) and the nymphs of Reptalus panzeri (Hemiptera: Cixiidae)

Gábor LŐRINCZI

Eur. J. Entomol. 109 (4): 509-515, 2012 | DOI: 10.14411/eje.2012.064

The nymphs of the cixiid planthopper, Reptalus panzeri (Löw, 1883), were found cohabiting with the myrmicine ant Aphaenogaster subterranea (Latreille, 1798) in a sub-Mediterranean oak forest in mid-western Hungary. Except for a few cases, nymphs were recorded only in the nests of A. subterranea, or were recorded with foragers of this ant from neighbouring colonies. Adult planthoppers were also found in nests of A. subterranea in the emergence period. Neither field nor laboratory studies revealed direct or unambiguous interactions between this ant and the planthopper nymphs that would indicate a trophobiotic relationship, however the fact that nymphs do not try to escape from the ants, which do not attack the nymphs, indicates some kind of mutualistic relationship between them. The main food plant of R. panzeri nymphs in this habitat is likely to be the roots of manna ash (Fraxinus ornus).

Morphological and molecular evidence supporting the validity of Trialeurodes lauri and T. ricini (Hemiptera: Sternorrhyncha: Aleyrodidae)

Christopher MALUMPHY, M. Belen SUAREZ, Rachel GLOVER, Neil BOONHAM, Dominique W. COLLINS

Eur. J. Entomol. 104 (2): 295-301, 2007 | DOI: 10.14411/eje.2007.045

The whiteflies Trialeurodes lauri and T. ricini have been found to be moving in international plant trade. The taxonomic validity and separation of these species is relevant to the plant health quarantine services of the European Union as T. lauri is oligophagous, nor recorded as a virus vector and present in the EU, whereas T. ricini is polyphagous, reported to be a virus vector, and absent from the EU (except for the Canary Islands). Yet doubt has been cast on the validity of the two species, with the suggestion that T. lauri is merely a variant of T. ricini. The taxonomic relationship was therefore investigated using morphological and molecular data. One morphological character traditionally used for the separation of these two species, the arrangement of the submarginal papillae, was found to be unreliable but morphological differences between the two species were found in the cephalic setal state, body outline and dorsal pigmentation. However, the differences were subtle and not always reliable. The molecular data, based on the sequence of a fragment of the COI gene, support the hypothesis that T. ricini and T. lauri are distinct valid species.

Rapid discrimination of the common species of the stored product pest Liposcelis (Psocoptera: Liposcelididae) from China and the Czech Republic, based on PCR-RFLP analysis

Meng QIN, Zhi-Hong LI, Zuzana KUČEROVÁ, Yang CAO, Václav STEJSKAL

Eur. J. Entomol. 105 (4): 713-717, 2008

Psocids of the genus Liposcelis (Psocoptera: Liposcelididae) are stored product pests that are difficult to identify morphologically. A molecular method based on Restriction Fragment Length Polymorphism (RFLP) of the PCR-amplified 16S rDNA gene was developed for the rapid discrimination of four common species (L. bostrychophila, L. entomophila, L. decolor, and L. paeta). Different developmental stages and populations (P.R. China and Czech Republic) were tested. One DNA fragment of about 500 bp in length was amplified from genomic DNA and the fragment was then digested using the restriction endonuclease DraI. Identification of the relevant banding pattern allowed all the developmental stages and both sexes to be discriminated in the species tested. The banding patterns of L. entomophila from all populations were identical, while the relevant restriction digests and sequence analysis confirmed that the Chinese and Czech populations of L. bostrychophila, L. decolor, and L. paeta differed. In conclusion, PCR-RFLP with one pair of primers (16Sar and 16Sbr) and one restrictive endonuclease, DraI, proved a reliable method for rapidly discriminating the Liposcelis species tested.

A comparison of three trapping methods used to survey forest-dwelling Coleoptera

Esko HYVÄRINEN, Jari KOUKI, Petri MARTIKAINEN

Eur. J. Entomol. 103 (2): 397-407, 2006 | DOI: 10.14411/eje.2006.054

Sampling of insect communities is very challenging and for reliable interpretation of results the effects of different sampling protocols and data processing on the results need to be fully understood. We compared three different commonly used methods for sampling forest beetles, freely hanging flight-intercept (window) traps (FWT), flight-intercept traps attached to trunks (TWT) and pitfall traps placed in the ground (PFT), in Scots pine dominated boreal forests in eastern Finland. Using altogether 960 traps, forming 576 sub-samples, at 24 study sites, 59760 beetles belonging to 814 species were collected over a period of a month. All of the material was identified to species, with the exception of a few species pairs, to obtain representative data for analyses. Four partly overlapping groups were used in the analyses: (1) all, (2) saproxylic, (3) rare and (4) red-listed species. In terms of the number of species collected TWTs were the most effective for all species groups and the rarer species the species group composed of (groups 1-2-3-4) the larger were the differences between the trap types. In particular, the TWTs caught most red-listed species. However, when sample sizes were standardized FWTs and TWTs caught similar number of species of all species groups. PFTs caught fewer species of all species groups, whether the sample sizes were standardized or not. In boreal forests they seem to be unsuitable for sampling saproxylic, rare and red-listed species. However, the PFTs clearly sampled different parts of species assemblages than the window traps and can be considered as a supplementary method. The abundance distribution of saproxylic species was truncated lognormal in TWT and pooled material, whereas unclassified material failed to reveal lognormal distribution in all the trap types and pooled material. The results show that even in boreal forests sample sizes of at least thousands, preferably tens of thousands of individuals, collected by a high number of traps are needed for community level studies. Relevant ecological classification of material is also very important for reliable comparisons. Differences in the performance of trap types should be considered when designing a study, and in particular when evaluating the results.

Female copulatory tubes and the subdivision of the genus Anthocoris (Heteroptera: Anthocoridae: Anthocorini)

Yunling KE, Wenjun BU

Eur. J. Entomol. 104 (1): 89-98, 2007 | DOI: 10.14411/eje.2007.014

We report a systematic study of the female copulatory tubes of forty species in the genus Anthocoris, most of which are from the Northern Hemisphere. Our results indicate that female copulatory tubes can be used as a reliable character to identify females and analyze phylogenetic relationships in this genus. We propose thirteen species groups based on the copulatory tubes of females, other morphological characters of both sexes, and the previous species groups adopted in the continental faunas.

The parasitoid species complex associated with sexual and parthenogenetic Naryciinae (Lepidoptera: Psychidae): Integrating ecological and molecular analyses

Jelmer A. ELZINGA, Kees ZWAKHALS, Johanna MAPPES, Alessandro GRAPPUTO

Eur. J. Entomol. 108 (4): 635-650, 2011 | DOI: 10.14411/eje.2011.082

This study describes the parasitoid species complex associated with seven closely related species of sexual (Siederia rupicollella, S. listerella, Dahlica lazuri, D. charlottae and D. lichenella) and parthenogenetic (Dahlica fennicella and D. triquetrella) Naryciinae (Lepidoptera: Psychidae) in Central Finland. A thorough ecological analysis of all the species of parasitoids recorded was combined with analyses of molecular data. Mitochondrial and nuclear DNA data were obtained from all the species in order to (1) detect cryptic species associated with host specialization, (2) assign undescribed males to females, and (3) verify the morphological identification of closely related species. A DNA barcoding technique was employed to identify host species from parasitized larval remains. By sampling more than 10,000 host larvae, of which 25.7% were parasitized, nine parasitoid species were identified morphologically, including both koinobionts (Ichneumonidae: Diadegma incompletum, Macrus parvulus, Trachyarus borealis, T. solyanikovi, T. fuscipes, T. brevipennis and Braconidae: Meteorus affinis) and idiobionts (Ichneumonidae: Orthizema flavicorne, Gelis fuscicornis). Ecological characteristics such as time and mode of host attack, time of emergence and level of specialization differed widely. The results show that differences in parasitoid biology need to be taken into account when studying differences in percentage parasitism of sexual and parthenogenetic Naryciinae. The molecular data revealed that one parasitoid species M. parvulus may consist of two cryptic forms associated with the sexual and parthenogenetic hosts, respectively. The data further establishes that T. brevipennis and some T. fuscipes are in fact morphotypes of one species. The large variation in mitochondrial DNA within species and its inconsistency with nuclear DNA demonstrate that current species and genus delimitation is inadequate in the Trachyarus species group. Our study shows that it is essential to use DNA barcoding methods when investigating host-parasitoid complexes.

Does wing dimorphism affect mobility in Metrioptera roeselii (Orthoptera: Tettigoniidae)?

Dominik PONIATOWSKI, Thomas FARTMANN

Eur. J. Entomol. 108 (3): 409-415, 2011

Range shifts are among the most conspicuous effects of global warming. Marked changes in distribution are recorded both for highly mobile species of insects, which are capable of flight, and wing-dimorphic species with predominantly short-winged individuals. One of these species is the bush-cricket Metrioptera roeselii, which occasionally produces long-winged individuals. However, there is little known about the locomotory behaviour of wing-dimorphic insects. Yet to be able to predict potential range shifts it is necessary to know the dispersal potential of macropters. Therefore, an experiment was conducted in which individually marked M. roeselii were released at four sites. Different movement parameters, such as daily movement, activity radius, dispersal range, net displacement and crowding rate, were calculated. The statistical analyses showed that the movement of long-winged and short-winged individuals did not differ, but the percentage of individuals that were not seen again was twice as high for long-winged bush-crickets. These results suggest that most of the long-winged individuals that were seen again did not fly; i.e., they had the same basic mobility as the short-winged individuals. However, the comparatively low number of long-winged individuals that were seen again suggests that at least some macropters are long-distance dispersers, which is relevant for the dispersal process. The comparison of sexes showed that males were significantly more mobile than females. This sex-specific locomotory behaviour in M. roeselii might depend on a complex series of social interactions and physiological conditions.

Effect of shelter on reproduction, growth and longevity of the German cockroach, Blattella germanica (Dictyoptera: Blattellidae)

César GEMENO, Gregory M. WILLIAMS, Coby SCHAL

Eur. J. Entomol. 108 (2): 205-210, 2011 | DOI: 10.14411/eje.2011.028

German cockroaches spend most of the day in aggregations within shelters, which they leave in nocturnal foraging trips; cockroaches are rarely seen outside shelters during daylight hours. However, when population density exceeds shelter availability, diurnal aggregations form in exposed, unsheltered locations. To determine if shelter availability affects fitness of B. germanica, we reared cohorts of nymphs in laboratory arenas with or without shelters, and measured reproduction and longevity of tagged adults. When shelters were available in arenas, nymphs developed faster, adults gained more body mass, and females produced more fertile oothecae than when arenas lacked shelters. Therefore, shelter alone has a significant positive effect on growth and reproduction of B. germanica, and reducing or eliminating shelters should affect population growth of B. germanica in residential and industrial settings.

A review of the genus Zavrelia (Diptera: Chironomidae)

Torbjørn EKREM, Elisabeth STUR

Eur. J. Entomol. 106 (1): 119-144, 2009 | DOI: 10.14411/eje.2009.016

In this paper we review the taxonomy of the genus Zavrelia Kieffer, Thienemann & Bause and present emended generic diagnoses of all major life stages. Illustrated keys to larvae, pupae, adult males and females are presented as well as descriptions of four species new to science. Zavrelia species are only recorded from the northern hemisphere and comprise in total ten small to minute species. The following life stages and species are described: Larva, pupa, adult male and adult female of Zavrelia aristata sp. n., Zavrelia hudsoni sp. n., Zavrelia pentatoma Kieffer & Bause and Zavrelia sinica sp. n.; pupa and adult male of Zavrelia casasi sp. n.; and adult males of Zavrelia clinovolsella Guo & Wang and Zavrelia tusimatijea (Sasa & Suzuki). Zavrelia atrofasciata Kieffer and Stempellina paludosa Goetghebuer are proposed as new junior synonyms of Zavrelia pentatoma and lectotypes of Zavrelia nigritula, Zavrelia pentatoma and Stempellina paludosa are designated.

Cohort-splitting in the millipede Polydesmus angustus (Diplopoda: Polydesmidae): No evidence for maternal effects on life-cycle duration

Jean-François DAVID, Jean-Jacques GEOFFROY

Eur. J. Entomol. 108 (3): 371-376, 2011

Under seasonal conditions, Polydesmus angustus individuals born in the first part of the breeding season have a 1-year life cycle and those born later have a 2-year life cycle (cohort-splitting). In this study, 249 juveniles from four early broods (born in mid-July) and four late broods (born in September) were reared under similar laboratory conditions, to test for possible maternal influences on life-cycle duration. Development times of early- and late-born individuals were compared under four combinations of day length and temperature (16 h - 18°C, 16 h - 16°C, 12 h - 18°C and 12 h - 16°C). The results showed that development time varied significantly in response to day length, temperature and sex, but that of individuals in the early and late broods did not differ significantly (mean development times ± SE: 180 ± 6 and 183 ± 8 days, respectively). There were no significant interactions between birth period and other factors, indicating that the effects of day length, temperature and sex on development time were similar in early- and late-born individuals. This indicates that the extended life cycle of millipedes born late in the season is not maternally determined and that cohort-splitting is controlled entirely by the environmental conditions experienced by the offspring during their development. This conclusion is supported by the absence of significant variation in offspring live weight at birth measured at different times in the breeding season. The results are discussed in relation to the bet-hedging theory, which is often put forward to account for cohort-splitting in arthropods. In P. angustus, the results are consistent with either bet-hedging or adaptive plasticity, but further studies are required to decide which interpretation is correct.

The diversity of phoretic Mesostigmata on Ips typographus (Coleoptera: Scolytinae) caught in the Karkonosze forest

Dariusz J. GWIAZDOWICZ, Jacek KAMCZYC, Jerzy BLOSZYK

Eur. J. Entomol. 108 (3): 489-491, 2011

This study determined the scale of the phoresy of mesostigmatid mite by Ips typographus. Thirty pheromone traps in the Karkonosze National Park (Poland) caught 10,575 bark beetles on which there were 2,388 mesostigmatid mites belonging to eight species. The most numerous mites were Dendrolaelaps quadrisetus (1076 ind.) and Trichouropoda polytricha (1067 ind.).

A new species group and five new species of the genus Pavania (Acari: Dolichocybidae) associated with insects, with notes on leg chaetotaxy and the distribution of genera

Hamidreza HAJIQANBAR, Alexnder KHAUSTOV

Eur. J. Entomol. 107 (3): 441-453, 2010 | DOI: 10.14411/eje.2010.051

A new species group and five new species of mites of the genus Pavania Lombardini, 1949 belonging to the family Dolichocybidae (Acari: Heterostigmata) are described from Iran. Pavania gymnopleuri Hajiqanbar & Khaustov sp. n., P. sabzevarensis Hajiqanbar & Khaustov sp. n. and P. onthophagi Hajiqanbar & Khaustov sp. n., represent a new gymnopleuri species group. Two new species are also described in the fusiformis group: P. kamalii Hajiqanbar & Khaustov sp. n. and P. elongata Hajiqanbar & Khaustov sp. n. All new species are associated with scarabaeid and carabid beetles (Coleoptera: Scarabaeidae, Carabidae). This is the first record of the family Dolichocybidae from Iran. The leg setation and geographic distribution of all genera of this family are discussed and keys to genera and species of the genus Pavania are provided.

Orthopteran communities in the conifer-broadleaved woodland zone of the Russian Far East

Thomas FARTMANN, Martin BEHRENS, Holger LORITZ

Eur. J. Entomol. 105 (4): 673-680, 2008

We investigate orthopteran communities in the natural landscape of the Russian Far East and compare the habitat requirements of the species with those of the same or closely related species found in the largely agricultural landscape of central Europe. The study area is the 1,200 km2 Lazovsky State Nature Reserve (Primorsky region, southern Russian Far East) 200 km east of Vladivostok in the southern spurs of the Sikhote-Alin Mountains (134°E/43°N). The abundance of Orthoptera was recorded in August and September 2001 based on the number present in 20 randomly placed 1 m2 quadrates per site. For each plot (i) the number of species of Orthoptera, (ii) absolute species abundance and (iii) fifteen environmental parameters characterising habitat structure and microclimate were recorded. Canonical correspondence analysis (CCA) was used first to determine whether the Orthoptera occur in ecologically coherent groups, and second, to assess their association with habitat characteristics. In addition, the number of species and individuals in natural and semi-natural habitats were compared using a t test. A total of 899 individuals of 31 different species were captured, with numbers ranging between 2 and 13 species per plot. Species diversity was higher in semi-natural habitats than natural habitats. There was a similar but non-significant pattern in species density. Ordination analysis indicated four orthopteran communities, which were clearly separable along a moisture and vegetation density gradient. The natural sites in the woodland area of the Lazovsky Zapovednik are characterized by species-poor and low-density orthopteran assemblages compared to the semi-natural sites. But, the natural sites have a higher diversity of habitat specialists. Our findings corroborate the hypothesis that intermediate habitat disturbance levels support particularly species-rich animal communities at high densities. Under such regimes, orthopterans presumably mostly profit from the high diversity in plant species, which generates great structural and microclimatic heterogeneity.

Effect of insect-resistant transgenic maize on growth and development, utilization of nutrients and in vivo activity of the detoxification enzymes of the Asian corn borer, Ostrinia furnacalis (Lepidoptera: Pyralidae)

Min Juan SHI, Pei LING LU, Xiao Li SHI, Yi Zhong YANG

Eur. J. Entomol. 108 (4): 547-552, 2011 | DOI: 10.14411/eje.2011.070

There is little systematic research on the effect of transgenic maize expressing Bacillus thuringiensis (Bt) toxins on insect survival and the response in vivo of their detoxification enzymes. Results of laboratory bioassays indicate that the whorl leaves of transgenic maize lines G03-2396 and G03-2739 significantly affected the survival of neonate and third instar larvae of the Asian corn borer, Ostrinia furnacalis (Güenée). Neonate mortality two days after being fed on G03-2739 was 72.5% and exceeded 92.5% four days later. The percentage mortality of third instar larvae six days after being fed whorl leaves from G03-2396 exceeded 65%. The resistance of whorl leaves to insect attack was greater than that of maize-ears, but less effective against attacks by third instar larvae. Neonate development was more prolonged when they were fed on whorl leaves of both the transgenic maize lines. In contrast, low pupation (<80% of that recorded in the controls), ecolosion and fecundity were recorded following ingestion of maize-ears, with pupal weights 10-14 mg lower than that of controls. The growth rates of third instar larvae recorded three and six days after feeding on whorl leaves were lower, but food utilization, conversion and relative metabolism were not significantly affected. Relative food ingestion, relative growth rate and other nutritional indicators of third instar larvae were significantly lower six days after the ingestion of ears and that of fifth instar larvae after three days. In vivo activity of carboxylesterase was decreased to a greater degree after three days when the larvae were fed on whorl leaves than ears, with no significant effect on fifth instar larvae. Furthermore, in vivo activity of glutathione S-transferase (GST) of third instar larvae was significantly affected following the ingestion of whorl leaves. These results are discussed in the context of the literature on the resistance of transgenic plants and of improving the resistance of plants to attack by the different larval stages of insects.

Deterrence of feeding in Rhodnius prolixus (Hemiptera: Reduviidae) after treatment of antennae with a nitric oxide donor

Valeria SFARA, Eduardo N. ZERBA, Raúl A. ALZOGARAY

Eur. J. Entomol. 108 (4): 701-704, 2011 | DOI: 10.14411/eje.2011.089

The blood-sucking bug Rhodnius prolixus is the main vector of Chagas Disease in Colombia, Venezuela and several countries in Central America. Nitric oxide (NO) is a ubiquitous gaseous molecule present in most types of cell and participates in the olfactory pathway of insects. In this work, nitroso-acetyl-cysteine (SNAC), a nitric oxide donor, was topically applied to the antennae of fifth instar nymphs of R. prolixus. After SNAC treatment, these insects showed a dose-dependent reluctance to feed when provided with a living pigeon as the food source (ED50 = 5.2 µg/insect). However, there was no reluctance to feed when db-cGMP was applied to the antennae of nymphs. In another experiment, insects that had their antennae treated with SNAC were less attracted than the control group to a CO2 source. A possible role of NO in the olfactory pathway of R. prolixus is discussed.

Assembly rules for ground beetle communities: What determines community structure, environmental factors or competition?

Sonomi SHIBUYA, Kohei KUBOTA, Masahiko OHSAWA, Zaal KIKVIDZE

Eur. J. Entomol. 108 (3): 453-459, 2011

Species assembly in ground beetle (Coleoptera: Carabidae) communities in local microhabitats was studied in a forest. The following questions were addressed: are there important filters that sort the species in the assemblages? If so, what is the specific nature of these filters? In order to address these questions rarefaction analysis was used to determine whether ground beetle species are distributed non-randomly. Next, the nature of filters was determined by analyzing (1) the community matrix and searching for the consequences of competitive exclusion and (2) species-environmental relations. Rarefaction analysis revealed that the species composition is filtered: species richness was less than expected and there were fewer than expected congeneric species coexisting at high beetle population densities. However, community matrix and body size analyses did not detect significant competition among the beetle species and the matrix was significantly nested. Species-environmental analyses indicated that the ground beetle assembly was strongly linked to ground vegetation. It is concluded that spatial distribution of ground beetles across local communities in this forest habitat is determined more by local environmental conditions than competition, and ground beetles do not interact strongly among themselves so that competitive effects do not play an important role in their distribution except at high beetle population densities.

Increasing patch area, proximity of human settlement and larval food plants positively affect the occurrence and local population size of the habitat specialist butterfly Polyommatus coridon (Lepidoptera: Lycaenidae) in fragmented calcareous grasslands

Zuzanna M. ROSIN, Piotr SKÓRKA, Magdalena LENDA, Dawid MORON, Tim H. SPARKS, Piotr TRYJANOWSKI

Eur. J. Entomol. 108 (1): 99-106, 2011 | DOI: 10.14411/eje.2011.013

Which factors influence the occurrence, population size and density of species in fragmented habitat patches are key questions in population and conservation ecology. Metapopulation theory predicts that larger and less isolated habitat patches should positively influence species occurrence and population size. However, recent studies have shown that habitat quality, human activity and permeability of the landscape surrounding habitat patches may be also important. In this paper we test the relative effects of habitat patch characteristics, human settlement and landscape permeability on the occurrence, local population size and density of the Chalk-hill Blue Polyommatus coridon a charismatic butterfly inhabiting calcareous grasslands in a fragmented landscape in southern Poland. Patch occupancy rate (corrected for the butterfly detection probability) was 0.45. Habitat patch area, proximity of human settlement and cover of larval food plants positively affected occurrence of the Chalk-hill Blue. Local population size of the Chalk-hill Blue was positively affected by patch area and proximity of human settlement, and negatively by patch isolation. Local density was higher in patches located close to human settlement. Our study is one of the few showing a positive effect of human settlement on a grassland specialist butterfly although the mechanism hidden behind this phenomenon is unknown and requires further examination. In order to maintain local populations of the Chalk-hill Blue in southern Poland, conservation action should be focused on large, closely connected calcareous grasslands. Moreover, extensive management of this habitat should be maintained by local inhabitants who are better placed to undertake such work.

Ground-dwelling arthropod communities present in three types of Cantabrian (NW Spain) heathland grazed by sheep or goats

Rocío ROSA GARCÍA, Francisco J. OCHARAN, Berta M. JÁUREGUI, Urcesino GARCÍA, Koldo OSORO, Rafael CELAYA

Eur. J. Entomol. 107 (2): 219-227, 2010 | DOI: 10.14411/eje.2010.029

The abundance, diversity and community composition of ground-dwelling arthropods present in three different types of Cantabrian heathland grazed by small ruminants were studied. A factorial design of three vegetation types (heather-, gorse- or grass-dominated) and two grazer species (sheep or goats) with two replicates was established in twelve 0.6 ha paddocks. Ground-dwelling arthropods (Araneae, Opiliones, Isopoda, Julida, Microcoryphia, Hemiptera, Coleoptera and Hymenoptera) were recorded using pitfall traps and plant cover and canopy height assessed in each paddock in 2005, 2006 and 2007. Higher abundances and more families of ground dwelling arthropods were recorded in areas dominated by heather, although certain species were more numerous in areas dominated by grass. The direct effects of the grazer species on arthropods were subtle compared to their great effect on the vegetation. Significant interactions between grazer species and vegetation were observed for some taxa and the overall arthropod community composition. Gradient analyses indicate that arthropod assemblages that include Lycosidae, Opiliones and Carabidae differed between vegetation types and years, but are not affected by the grazer species. Our study shows that areas dominated by shrubby and diverse heather had the highest diversity and abundance of arthropods. Species composition varied along a gradient in the structure of the vegetation, which in turn was modified by the grazer species.

The role of plant phenology in the host specificity of Gephyraulus raphanistri (Diptera: Cecidomyiidae) associated with Raphanus spp. (Brassicaceae)

Janine VITOU, Marcela SKUHRAVÁ, Václav SKUHRAVÝ, John K. SCOTT, Andy W. SHEPPARD

Eur. J. Entomol. 105 (1): 113-119, 2008 | DOI: 10.14411/eje.2008.016

Recent host records for Gephyraulus raphanistri (Kieffer), a flower-gall midge, show restriction to Raphanus raphanistrum throughout Europe. Gephyraulus raphanistri has never been reported infesting commercially grown Brassica crops. Historical records showing a broad host range appear to have resulted from confusion with new or as yet undescribed Gephyraulus spp. and Contarinia nasturtii (Kieffer), a known gall-former of Brassica and other related genera. This study tested host specificity of G. raphanistri in the field in Europe by manipulating host plant phenology of actual and potential hosts in the genera Raphanus and Brassica as part of a risk assessment of the insect as a potential biological control agent of R. raphanistrum, one of the most important weeds of crops in Australia. Raphanus raphanistrum raphanistrum (wild radish), R. raphanistrum landra (coastal wild radish), Raphanus sativus (radish) and Brassica napus (oilseed rape cultivar) were phenologically synchronised for initial flowering and planted out in a flowering time and species block design near a natural population of R. r. landra hosting a natural population of G. raphanistri. Three generation peaks in gall formation were observed in the experiment, with galls developing on all test plants with an apparent preference for R. r. landra. The high field specificity of this gall midge is driven by the synchrony of oviposition and flower availability, not host physiological incompatibility or behavioural unacceptability. Commercially grown Brassica spp. are not suitable hosts for G. raphanistri because in the field they differ in flowering phenology from Raphanus raphanistrum. The overlap in the flowering phenology of the crop and weed in Australia makes this insect unsuitable as a biological control agent.

Phylogeny of European Dolichopus and Gymnopternus (Diptera: Dolichopodidae) and the significance of morphological characters inferred from molecular data

Marco Valerio BERNASCONI, Marc POLLET, Manuela VARINI-OOIJEN, Paul IRVINE WARD

Eur. J. Entomol. 104 (3): 601-617, 2007 | DOI: 10.14411/eje.2007.075

Dolichopodidae (over 6000 described species in more than 200 genera) is one of the most speciose families of Diptera. Males of many dolichopodid species, including Dolichopus, feature conspicuous ornaments (Male Secondary Sexual Characters) that are used during courtship. Next to these MSSCs, every identification key to Dolichopus primarily uses colour characters (postocular bristles; femora) of unknown phylogenetic relevance. The phylogeny of Dolichopodidae has rarely been investigated, especially at the species level, and molecular data were hardly ever involved. We inferred phylogenetic relationships among 45 species (57 samples) of the subfamily Dolichopodinae on the basis of 32 morphological and 1415 nucleotide characters (810 for COI, 605 for Cyt-b). The monophyly of Dolichopus and Gymnopternus as well as the separate systematic position of Ethiromyia chalybea were supported in all analyses, confirming recent findings by other authors based purely on morphology. Within Dolichopus, stable species groups could be assigned to four distinct categories on the basis of their statistical support in 7 phylogenetic analyses: (i) clades significantly supported in all analyses, (ii) clades supported in trees based on DNA and combined data, but only partly in morphological trees, (iii) clades significantly supported in trees based on DNA and combined data, but not in morphological trees, and (iv) clades consistently supported only in morphological trees. The phylogeny generated here provides a better understanding of the phylogenetic relevance of some debated morphological characters used for species and species-group characterizations in the most commonly used identification keys. In this respect, postocular bristle colour proved of little phylogenetic relevance since every group with species featuring black bristles also included species with partly yellow bristles. Entirely or partly infuscated femora explained the nodes of three stable species groups and even revealed an incorrect polarity of this morphological character in three species. Four of 6 complex MSSCs and 5 of 8 more common MSSCs were found consistently in further species groups.

Short term response of ants to the removal of ground cover in organic olive orchards

Mercedes CAMPOS, Luisa FERNÁNDEZ, Francisca RUANO, Belén COTES, Manuel CÁRDENAS, Juan CASTRO

Eur. J. Entomol. 108 (3): 417-423, 2011

Ants are the most abundant group of soil arthropods in olive groves where they are involved in various trophic relationships of great importance for crops. The system of soil management is one agricultural practice that has a great effect on ants, so the objective of this study was to compare ant populations in organic olive orchards with a ground cover of natural vegetation and others where this natural vegetation is mechanically removed at the beginning of June. Ants were sampled using pitfall traps at 14, 30, 70 and 90 days after the removal of the ground vegetation. Overall, ant biodiversity did not change. However, changes were observed in the abundance of ant species, in particular, in those species that build shallow nests in the soil, both between the rows of trees and under the canopy of olive trees. In contrast, deep nesting species, such as Messor barbarus, were not affected. The response also differed between the various genera: the abundance of Cataglyphis increased, due to there being more of the species C. rosenhaueri, while there was a significant fall in Aphaenogaster, due to the decline in abundance of A. senilis. Thirty days after the removal of vegetation, the response of most of the genera was clearly noticeable, due to the increased activity of workers, and in some cases there were still differences after 90 days.

Determining the season of death from the family composition of insects infesting carrion

Thiago De Carvalho MORETTI, Vinícius BONATO, Wesley Augusto Conde GODOY

Eur. J. Entomol. 108 (2): 211-218, 2011 | DOI: 10.14411/eje.2011.029

Determining the season of death by means of the composition of the families of insects infesting carrion is rarely attempted in forensic studies and has never been statistically modelled. For this reason, a baseline-category logit model is proposed for predicting the season of death as a function of whether the area where the carcass was exposed is sunlit or shaded and of the relative abundance of particular families of carrion insects (Calliphoridae, Fanniidae, Sarcophagidae, and Formicidae). The field study was conducted using rodent carcasses (20-252 g) in an urban forest in southeastern Brazil. Four carcasses (2 in a sunlit and 2 in a shaded area) were placed simultaneously at the study site, twice during each season from August 2003 through June 2004. The feasibility of the model, measured in terms of overall accuracy, is 64 ± 14%. It is likely the proposed model will assist forensic teams in predicting the season of death in tropical ecosystems, without the need of identifying the species of specimens or the remains of carrion insects.

Identification of limonene as a potential kairomone of the harlequin ladybird Harmonia axyridis (Coleoptera: Coccinellidae)

Ammar ALHMEDI, Eric HAUBRUGE, Frédéric FRANCIS

Eur. J. Entomol. 107 (4): 541-548, 2010 | DOI: 10.14411/eje.2010.062

Chemical cues involved in both host location and oviposition by Harmonia axyridis Pallas (Coleoptera: Coccinellidae) were investigated in laboratory and field experiments. Among the five volatiles tested in a four-arm olfactometer ((E)-β-farnesene, β-pinene, β-caryophyllene, cis-3-hexen-1-ol, and limonene), gravid H. axyridis females were significantly attracted to limonene and β-caryophyllene. These two chemicals also increased H. axyridis oviposition on plants. Attraction of H. axyridis towards limonene was further tested under field conditions using controlled-release dispensers. (E)-β-farnesene, a major aphid alarm pheromone and a potential predator kaironome, was also tested in this study. Field data confirmed those from laboratory studies concerning the attraction of H. axyridis towards limonene and a lack of response to (E)-β-farnesene. In contrast, the aphid predator Episyrphus balteatus DeGeer (Diptera: Syrphidae) was attracted to (E)-β-farnesene but not to limonene. These findings indicate that H. axyridis uses chemicals, such as limonene, for prey location and oviposition, and support the potential use of volatiles in the management of H. axyridis.

Detection of oviposition-deterring larval tracks in Chrysopa oculata and Chrysopa perla (Neuroptera: Chrysopidae)

Zdeněk RŮ®IČKA

Eur. J. Entomol. 107 (1): 65-72, 2010 | DOI: 10.14411/eje.2010.008

We investigated the ability of females of the aphidophagous chrysopids Chrysopa oculata and Chrysopa perla to distinguish clean substrates from substrates with tracks of chrysopid first instars after ablation of various sensory organs potentially involved in the detection of oviposition-deterring semiochemicals (ODSCs). Also studied were effects of storage time on the degree of oviposition deterrence of substrates contaminated by larvae and by extracts of ODSC in intact females. C. oculata and C. perla laid significantly fewer eggs on substrates with conspecific larval tracks than on simultaneously provided clean substrates. Females of both chrysopids could perceive ODSCs solely through sense organs on the head. The oviposition of each species was significantly lower on contaminated than on clean substrates when any kind of sense organ on the head was completely removed, i.e. antennae, maxillary palpi, or labial palpi. C. oculata could still effectively differentiate substrates after ablation of both maxillary and labial palpi, indicating possible detection of volatiles via the antennae during flight. Only if all three pairs of sensory appendages were removed did females lay similar numbers of eggs on both substrates. In contrast, C. perla laid similar numbers of eggs on clean substrates and substrates with either conspecific or C. oculata larval tracks when maxillary and labial palpi were removed. Substrates with tracks of first instars of C. perla deterred C. oculata from oviposition after one year and conspecific females after 1.5 years from contamination. Both species laid significantly fewer eggs on substrates with tracks of C. oculata first instars than on clean substrates even after three years. Tracks of C. oculata third instars did not deter conspecific females more than tracks of first instars. ODSCs from tracks were easily extracted with water. Thus, precipitation is likely to reduce deterrent effects of contaminated plants. Chloroform extract from C. oculata first instars strongly deterred conspecific females from oviposition. Even after 725 days of storage, we found no statistically significant decline in the effect. The extract could be used to redirect egg laying from constructional parts of rearing cages to exchangeable oviposition substrates in mass rearing of chrysopids used for biological control. The hexane extract of third instars was inactive.

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