Fulltext search in archive



« advanced mode »

 previous    ...   9   10   11   12   13  14   15   16   17   18   ...    next 

Results 361 to 390 of 1601:

First chromosomal study of Mantophasmatodea: Karyotype of Karoophasma biedouwense (Austrophasmatidae)

Dorota LACHOWSKA-CIERLIK, Anna MARYAŃSKA-NADACHOWSKA, Valentina KUZNETSOVA, Mike PICKER

Eur. J. Entomol. 112 (4): 599-605, 2015 | DOI: 10.14411/eje.2015.093

We have investigated for the first time the chromosomes of Karoophasma biedouwense, a species belonging to the Mantophasmatodea, a recently discovered order of carnivorous insects. Our study has revealed that males of this species display testes with numerous seminal tubes (follicles), as in other Polyneoptera, and short tubular seminal vesicles embedded in a utricular gland. The karyotype consists of 2n = 12A + X monocentric and biarmed, meta/submetacentric chromosomes (fundamental number of arms: FN = 26) with blocks of heterochromatin around centromeres. The autosomes are classified into two size groups, one represented by a single, very large pair of autosomes, the other by five smaller pairs which constitute a continuous series gradually decreasing in size. Among "monocentric" orders of Polyneoptera, K. biedouwense shares its low chromosome number, 2n = 13, as also found with some Orthoptera (Acridoidea, Grylloidea, Gryllacridoidea). Male meiosis is of the classical pre-reductional type and the X(0) sex determination system is probably an ancestral state. Use of FISH along with an 18S rDNA probe revealed multiple ribosomal clusters, which most likely represent an apomorphic condition. We identified the ancestral insect telomeric sequence (TTAGG)n in the terminal areas of the chromosomes. Currently available data on the polyneopteran orders putatively related to Mantophasmatodea showed a wide variability of cytogenetic characteristics within and between them. The only character allowing some tentative inference to be made on the ancestry of K. biedouwense is its low chromosome number, the karyotypic pattern so far unreported for the Polyneoptera except in certain Orthoptera.

Adult demography, spatial distribution and movements of Zerynthia polyxena (Lepidoptera: Papilionidae) in a dense network of permanent habitats

Tatjana ČELIK

Eur. J. Entomol. 109 (2): 217-227, 2012 | DOI: 10.14411/eje.2012.028

The adult demographic parameters, mobility, nectar choice and how the spatial distribution of males and females of Z. polyxena is affected by the distribution and abundance of host-plants, and adults of the opposite sex was studied in a population of this species inhabiting a dense network of permanent habitats (totalling 8.7 ha). The population size was estimated to be ca. 300 individuals. The average adult lifespan was 4.4 days and the maximum 23 (male) and 20 (female) days. The capture probability was higher for males than females due to the more conspicuous behaviour and bounded area of activity of males. A slow increase was followed by a slow decrease in the sex specific parabolic recruitment curve, indicating slight protandry and long emergence period, probably due to habitat heterogeneity. The spatial distribution of host plants (Aristolochia lutea) is the key factor determining the spatial distribution of adults. There was a strong positive correlation between male and female density at each patch, both of which were dependent on the cover of host plants growing in sunny conditions. In searching for A. lutea plants suitable for oviposition, females fly greater distances and move more frequently between patches than males. The size, shape and orientation of the male home range were influenced by the size, shape and orientation of stands of host-plants in sunny positions, but not by patch area. Such adult fidelity to stands of host-plants in sunny positions indicates that the spatial distributions of oviposition sites, mate-locating sites and larval habitats of Z. polyxena overlap. The better statistical fit and much lower probabilities for long-distance movements generated by a negative exponential function than an inverse power function are probably due to the small size and high habitat connectivity of the site studied. Adults were opportunistic in their use of nectar plants. Traditional management is the key factor for maintaining permanent habitats for this species in a grassland biotope.

Facultative parthenogenesis in the burrowing mayfly, Ephoron eophilum (Ephemeroptera: Polymitarcyidae) with an extremely short alate stage

Kazuki SEKINÉ, Koji TOJO, Yeon Jae BAE

Eur. J. Entomol. 112 (4): 606-612, 2015 | DOI: 10.14411/eje.2015.074

Facultative parthenogenesis is important for mayflies with short alate stages because females are able to reproduce without mating. We studied facultative parthenogenesis in Ephoron eophilum, a mayfly with an extremely short alate stage. We examined the survival rates of embryos from unfertilized eggs, in addition to investigating the number of chromosomes in parthenogenetic offspring and the mode of inheritance by nuclear genetic analyses using Exon-Primed Intron-Crossing markers. The survival rate of thelytokous embryos was 0-70.2% (16.7 ± 26.7%, mean ± S.D.). Sixteen chromosomes were present throughout most of the mitotic metaphase in parthenogenetic offspring, which was similar to the number recorded in diploid females. All parthenogenetic offspring were homozygous in nuclear genetic analyses, despite the presence of heterozygous mothers. These results indicate that E. eophilum has the ability to reproduce via facultative parthenogenesis, producing mostly diploid thelytokous offspring. The restoration of ploidy level occurs by automixis via terminal fusion or gamete duplication, and causes rapid reduction of heterozygosity. However, despite this, significant deviation from Hardy-Weinberg equilibrium (HWE) was not observed in the studied populations. This is because facultative parthenogenesis in these circumstances normally has little influence on population genetic structuring, even though parthenogenetic embryos exhibit a high survival rate. The lack of influence of parthenogenesis on the population structure of the natural population strongly suggests that parthenogenesis rarely occurs under natural circumstances.

Pollen resources used by Chrysoperla agilis (Neuroptera: Chrysopidae) in the Azores, Portugal

Leila NUNES MORGADO, Roberto RESENDES, Mónica MOURA, Maria A. MATEUS VENTURA

Eur. J. Entomol. 111 (1): 143-146, 2014 | DOI: 10.14411/eje.2014.015

There are approximately 1200 described species of Chrysopidae, many of which are predators of agricultural pests. Species of Chrysoperla are mass-produced and sold for use as biological control agents of agricultural pests in Europe, Asia, North and South America. Chrysoperla agilis, a member of the "carnea group" of Chrysoperla, has the potential to be biocontrol agent and is native to the Azores, and therefore a local candidate for use in IPM of pests, such as aphids and scale insects. Given that many adult Chrysopidae feed on pollen and honeydew and the biology of Ch. agilis is not well understood, we studied the preferences of Ch. agilis adults living in a greenhouse on the campus of the University of the Azores for feeding on different types of pollen. Twenty-six species of flowering plants, belonging to 16 families and 24 genera, all previously recorded on Sao Miguel Island, were found in the greenhouse. Pollen grains from each species were collected and incorporated in a reference catalogue. Additionally, 40 adults of Ch. agilis were collected (20 in December 2012 and 20 in January 2013) and the pollen in guts identified. Of the 26 species of plants in the greenhouse 14 were used as sources of pollen by the lacewings. Pollen of Plantago lanceolata L. was the most frequently recorded pollen in the gut contents. The adults of this chrysopid fed mainly on the pollen of species of plants belonging to the Asteraceae, Plantaginaceae and Poaceae. The species richness (S = 12), diversity index (H' = 2.123) and equitability (J' = 0.8543) of the January sample are greater than those of the December sample. Similarity of the samples collected in the 2 months was 0.75. From these results we infer that it is important to maintain or increase plant biodiversity in agroecosystems as weeds provide trophic resources for insects that are beneficial to agriculture.

Longevity of starved bumblebee queens (Hymenoptera: Apidae) is shorter at high than low temperatures

Salla-Riikka VESTERLUND, Jouni SORVARI

Eur. J. Entomol. 111 (2): 217-220, 2014 | DOI: 10.14411/eje.2014.035

Northern bumblebees (Hymenoptera: Apidae) with annual lifecycles depend both on energy stores remaining in their fat body after diapause and a few spring flowering plants. Most temperate bumblebees emerge gradually over several months after winter depending on the species and within species on the location of the overwintering chamber (hibernaculum). Weather can either delay or promote emergence and nectar resources are needed to fuel flight at low ambient temperatures to find a nest site. Several phoretic mites use queens for transportation and have synchronized life cycles with their host species. Their presence on the body of bumblebees is usually harmless but can become harmful when the number of mites increases to hundreds per individual bee. High numbers of mites on queens may also indicate the queens are in poor condition. The effect of temperature and mite load on the time for which queens can survive (d) during a 25-day period of starvation were determined using newly emerged spring queens of B. lucorum. Queens collected from various locations in SW Finland were divided into four groups taking into account their initial load of Parasitellus fucorum mites: (A) 15°C and provided with only water; (B) 24°C and provided with only water; (C) 15°C and provided with pollen and nectar; (D) 24°C and provided with pollen and nectar. There were mites on 65% (50 out of 77) of the queens. All of the fed queens survived and starved queens died, with those kept at 24°C dying approximately 8 days before those kept at 15°C. Queen weight or mite load had no effect on the length of the period for which they survived and there was no difference in the weights of the queens in the different mite load classes. Asynchrony between plants and insect as well as increased frost damage due to climate change may affect nectar availability in spring. Therefore, the survival and long term viability of bumblebee populations should be monitored during variable spring conditions.

Weed seed choice by carabid beetles (Coleoptera: Carabidae): Linking field measurements with laboratory diet assessments

Sandrine PETIT, Aline BOURSAULT, David A. BOHAN

Eur. J. Entomol. 111 (5): 615-620, 2014 | DOI: 10.14411/eje.2014.086

Carabid beetles could potentially provide a number of ecosystem services in arable fields, including the regulation of weeds by eating seeds. Spatio-temporal variability in the incidence of predation combined with a limited understanding of the interactions between carabids and seed predation, currently limits our ability to assess the effectiveness of this service. We carried out a long-term field study of carabid communities and the incidence of predation of the seeds of 5 species of weeds and laboratory cafeteria choice-tests to quantify the preferences of the most abundant species of seed-eating carabid for the seeds of 10 species of weeds. The field study revealed important temporal variation both in carabid activity-density and seed predation, with the seed of Viola arvensis and Capsella bursa-pastoris being particularly preferred by the carabids. The laboratory cafeteria tests confirmed the predation preferences measured in the field, in showing strong preferences by both Pterostichus melanarius and Pseudoophonus rufipes for the seed of V. arvensis. The percentage predation of the seed of V. arvensis was associated with the activity-density of carabids, while that of the seed of C. bursa-pastoris was not. Integrating laboratory-measured daily consumption rates, per carabid taxa, into models improved the ability to predict the intensity of predation of the seed of V. arvensis based on the composition of carabid communities.

Dispersal of individuals of the flightless grassland ground beetle, Carabus hungaricus (Coleoptera: Carabidae), in three populations and what they tell us about mobility estimates based on mark-recapture

Zoltan ELEK, Lukáą DRAG, Pavel POKLUDA, Lukáą ČÍ®EK, Sándor BÉRCES

Eur. J. Entomol. 111 (5): 663-668, 2014 | DOI: 10.14411/eje.2014.080

Knowledge of the dispersal ability of endangered species is crucial for developing effective, evidence-based conservation policies. Due to their limited dispersal abilities and specific habitat requirements, insects are among the animals most threatened by habitat fragmentation. We studied three populations of the highly endangered species of ground beetle, Carabus hungaricus, at three sites in Central Europe (Hungary and Czech Republic) using mark-release-recapture (MRR). The total catch of 574 pitfall traps set at the three sites was 6255 individuals. Depending on the site, the percentage recaptured was 13-32%. Average and maximum distance moved by individuals of both sexes at each of the sites ranged between 47-132 and 207-1104 m, respectively. The probability of the movements following an inverse power function (IPF) for the two sexes did not differ, but did differ among sites. Probability of dispersing for distances >100 m differed by an order of magnitude between sites, most likely because of differences in how the samples were collected. Despite the fact that individual beetles are able to move over distances in the order of kilometres, the high fragmentation of their habitats is likely to prevent them from colonizing most uninhabited habitat patches. Therefore, the conservation of this threatened ground beetle could be improved by adopting and implementing a policy of assisted dispersal. Our results from three study sites also provide an interesting illustration of the variability in the estimates of the probability of dispersal obtained using MRR.

Seasonal cues mediate host behaviour modification and cocoon polymorphism in Microplitis mediator (Hymenoptera: Braconidae)

Shu-Ping LUO, J.P. MICHAUD, Jian-Cheng LI, Jing ZHANG, Xiao-Xia LIU, Qing-Wen ZHANG

Eur. J. Entomol. 110 (2): 271-276, 2013 | DOI: 10.14411/eje.2013.040

Laboratory experiments were conducted to examine the effects of photoperiod and temperature on the pupation behaviour of the parasitoid, Microplitis mediator (Haliday) (Hymenoptera: Braconidae), parasitizing larvae of Mythimna separata Walker (Lepidoptera: Noctuidae). A combination of long photoperiod (14 + h L) and warm temperatures (20-24°C) caused parasitized caterpillars to climb to upper plant parts where the parasitoid produced a green, non-diapausing cocoon on a green leaf, initially retaining the dying caterpillar host as a protective covering. In contrast, short photoperiod (8-10 h L) and low temperature (16-18°C) induced host caterpillars to descend the plant where the parasitoid produced a brown, diapausing cocoon either hanging by silk from a senescing leaf or simply lying on the soil, but without any continued association with the host. These findings illustrate the potential for seasonal environmental cues to simultaneously mediate diapause induction, cocoon polymorphism, and alternate forms of host behaviour modification in a hymenopterous parasitoid.

Strategy for sneaking into a host's home: The cuckoo wasp Omalus biaccinctus (Hymenoptera: Chrysididae) inserts its eggs into living aphids that are the prey of its host

Patrick WINTERHAGEN

Eur. J. Entomol. 112 (3): 557-559, 2015 | DOI: 10.14411/eje.2015.064

Parasitic Hymenoptera usually need to have direct access to their host or its offspring or to be able to enter and place their offspring in a nest of their host, where their progeny develop at the expense of the host. In the case of the cleptoparasitic cuckoo wasps (Chrysididae) their main target is the nest of the host and they have various strategies for locating and entering their host's brood cells for ovipositing. The chrysidid Omalus biaccinctus (Buysson, 1893), a parasitoid of aphid hunting crabronid wasps, was observed apparently inserting its eggs into living aphids at the hunting site of their host and the presence of the parasitoid's egg and DNA in aphids after oviposition was confirmed. It is concluded that O. biaccinctus "hitch-hikes" into a host's brood cell concealed in the aphid prey collected by the host wasp and the adult parasites do not need to enter the nest of their host in order to lay their eggs.

Species composition and dynamics in abundance of migrant and sedentary butterflies (Lepidoptera) at Gibraltar during the spring period

Keith J. BENSUSAN, Rebecca NESBIT, Charles E. PEREZ, Piotr TRYJANOWSKI, Piotr ZDUNIAK

Eur. J. Entomol. 111 (4): 555-559, 2014 | DOI: 10.14411/eje.2014.057

In order to understand patterns of abundances of migratory Lepidoptera in southernmost Europe and contrast this with those of sedentary species, we studied butterflies surveyed along transects during three spring migration seasons at the Rock of Gibraltar. Overall, 2508 butterflies belonging to 19 species were recorded. Of these, the four most numerous species accounted for almost 88% of all individuals recorded. These were the migratory Clouded Yellow Colias croceus, Red Admiral Vanessa atalanta and Painted Lady Vanessa cardui, and the sedentary Common Blue Polyommatus icarus. There was a significant correlation between abundance of P. icarus and C. croceus. Furthermore, abundances of C. croceus and V. atalanta were correlated. The sometimes very high abundance of migratory butterflies at the study site could suggest that Gibraltar is a stopover site for butterflies migrating between Africa and Europe.

Preference of two populations of Propylea quatuordecimpunctata (Coleoptera: Coccinellidae) for Aphis fabae and Aphis gossypii (Homoptera: Aphididae)

Maryam KESHAVARZ, Marjan SEIEDY, Hossein ALLAHYARI

Eur. J. Entomol. 112 (3): 560-563, 2015 | DOI: 10.14411/eje.2015.065

Prey preference of natural enemies is an important parameter used in studies on their efficiency. Feeding preferences of individuals from two populations of Propylea quatuordecimpunctata (L.) (Coleoptera: Coccinellidae) for the essential prey items, Aphis fabae Scopoli, 1763 and Aphis gossypii Glover, 1877 (Homoptera: Aphididae) were evaluated in the laboratory using Manly's β preference index (β). For the predator preference experiment, equal numbers of A. fabae and A. gossypii were offered to the predator. The experiment was conducted on a broad bean leaf disc with 20 replicates. After 24 h, the unconsumed aphids were counted. Individuals of P. quatuordecimpunctata from both populations consumed more A. gossypii [Karaj population (mean ± SE): 28.15 ± 1.04 and Sari population 34.35 ± 0.51] than A. fabae (Karaj population: 17.95 ± 0.64 and Sari population: 17.7 ± 1.01). The values of Manly's β preference index (β) for A. gossypii were 0.73 ± 0.01 and 0.77 ± 0.01 for the Karaj and Sari populations, respectively and for A. fabae were 0.26 ± 0.01 and 0.22 ± 0.01 for the Karaj and Sari populations, respectively. Comparison of the preference indices using a t-test revealed significant differences between the prey preferences of those from the Sari population (t = 22.53, df = 38, P < 0.0001) and the Karaj population (t = 26, df = 38, P < 0.0001). These results reveal that P. quatuordecimpunctata from the two populations prefer A. gossypii over A. fabae.

Molecular cloning and characterization of the S6K-p70 gene in Chinese honeybees, Apis cerana cerana (Hymenoptera: Apidae)

Yingqi CAI, Taobo AI, Xiaoli YU, Baohua XU, Xingqi GUO

Eur. J. Entomol. 110 (1): 21-30, 2013 | DOI: 10.14411/eje.2013.003

The ribosomal protein S6 kinase (S6K) plays a pivotal role in developmental processes and cell survival by participating in protein synthesis relevant signaling pathways. In the present study, an S6K gene (AccS6K-p70) was isolated and characterized from the Chinese honeybee, Apis cerana cerana (Fabricius) (Hymenoptera: Apidae), an important economic insect in the agricultural industry. The cDNA of AccS6K-p70 was 1683 bp in length and predicted to encode a protein of 467 amino acid residues. Sequence and structure analysis showed that there was a conserved catalytic domain in AccS6K-p70, whilst a phosphorylation site was found in the conserved part of the catalytic domain. Development relevant transcription factor binding sites found in the 5'-flanking region of AccS6K-p70 suggest that AccS6K-p70 might be involved in A. c. cerana development. Furthermore, quantitative PCR revealed that the expression levels of AccS6K-p70 were higher in head and thorax than in other tissues. The AccS6K-p70 was highly expressed in both larvae and adults compared with that in pupae, whilst expression of the gene was significantly down-regulated by hydrogen peroxide (H2O2) (although initially and slightly increased by it) and pyriproxyfen (a juvenile hormone analogue insecticide) stresses. These results suggest that AccS6K-p70 may play critical roles in developmental processes and cell survival in A. c. cerana, whilst both oxidative stress and pyriproxyfen may impair S6K-p70 mediated developmental processes by down-regulation of AccS6K-p70 expression.

Biogeography of tenebrionid beetles (Coleoptera: Tenebrionidae) in the circum-Sicilian islands (Italy, Sicily): Multiple biogeographical patterns require multiple explanations

Simone FATTORINI

Eur. J. Entomol. 108 (4): 659-672, 2011 | DOI: 10.14411/eje.2011.084

The tenebrionid beetles on 25 circum-Sicilian islands were studied to determine the influence of island geographical and landscape features on three main intercorrelated biogeographical patterns: (1) species richness, studied using species-area and species environment relationships, (2) species assemblage composition, investigated using Canonical Correspondence Analysis (CCA), and (3) inter-site faunal similarity, investigated using Canonical Correlation Analysis (CANCOR) applied to multidimensional scaling of inter-island faunal dissimilarities. Species richness was mostly influenced by island area and landscape heterogeneity (expressed using various indices of diversity based on land cover categories). When species identities were considered in the CCA, no substantial effect of landscape was detected. Current island isolation did not have a strong influence on species richness, but has a distinct effect in determining species assortments on the remotest islands. Historical influences of Pleistocene landbridge connections were not detectable in species richness relationships using geographical variables in species richness analyses or in assemblage gradients in the CCA, but emerged distinctly from inter-island similarities in the CANCOR.

Behavioural evidence for a putative oviposition-deterring pheromone in the butterfly, Phengaris (Maculinea) teleius (Lepidoptera: Lycaenidae)

Marcin SIELEZNIEW, Anna M. STANKIEWICZ-FIEDUREK

Eur. J. Entomol. 110 (1): 71-80, 2013 | DOI: 10.14411/eje.2013.009

Larvae of the endangered Scarce Large Blue butterfly, Phengaris (Maculinea) teleius, are initially endophytic, feeding upon developing seeds of Sanguisorba officinalis, but complete their development as social parasites preying on the brood of Myrmica ants. Females show very specific preferences, laying eggs exclusively in young flower heads of the food plant. In the present contribution we report the results of a detailed study of female behaviour at three sites differing in size and abundance of S. officinalis. Tracked individuals switched between feeding on nectar (nectaring), flight and oviposition. They fed exclusively on flowers of reddish, pink or violet colouration, favouring Viccia cracca and S. officinalis. However, females spent about one fifth of the time they were active ovipositing and laid about 20 eggs per hour. Oviposition visits to flower heads were highly stereotyped and followed a specific ritual. Examination of accepted, rejected and randomly sampled flower heads showed that females avoided those containing conspecific eggs and at a site where this was difficult due to a shortage of suitable flower heads, they tended to distribute their eggs evenly among the available flower heads. Our results indirectly indicate the existence of an oviposition-deterring pheromone (ODP) in P. teleius. This hypothetical marking ensures a more even distribution of eggs and possibly increases the chances of survival of caterpillars by reducing competition during both the phytophagous and myrmecophagous stages of development. There are few reports of butterflies producing ODPs and to our knowledge this is the first evidence of their presence in the family Lycaenidae.

Invertebrates in urban areas: A review

Elizabeth L. JONES, Simon R. LEATHER

Eur. J. Entomol. 109 (4): 463-478, 2012 | DOI: 10.14411/eje.2012.060

As urbanisation is set to continue, understanding the impact on wildlife becomes increasingly important if we are to be able to conserve biodiversity. As an excellent group of bioindicators, invertebrates can allow us to understand some of the forces in urban areas which impact upon biodiversity and wildlife populations. This paper discusses some of the trends in the abundance, diversity and richness of invertebrates related to urbanisation and the specific urban environmental and traffic factors which may be at play.

Fungi associated with the red-haired bark beetle, Hylurgus ligniperda (Coleoptera: Curculionidae) in the forest-steppe zone in eastern Ukraine

Kateryna DAVYDENKO, Rimvydas VASAITIS, Valentyna MESHKOVA, Audrius MENKIS

Eur. J. Entomol. 111 (4): 561-565, 2014 | DOI: 10.14411/eje.2014.070

The aim of this study was to investigate the composition of the fungal community associated with the red-haired bark beetle (Hylurgus ligniperda Fabricius) in two plantations of Pinus sylvestris L. located in the Kharkiv and Luhansk regions (ca. 250 km apart) in the forest-steppe zone in eastern Ukraine. In each plantation, 48 beetles were collected from butts of living trees and 48 beetles from stems of fallen trees, i.e., a total of 96. Half of the beetles from each site were used for culturing fungi and the other half for direct sequencing the internal transcribed spacer of fungal ribosomal RNA (ITS rRNA). Thirty distinct fungal taxa were identified by culturing and 31 by direct sequencing. When pooled, there were 40 fungal taxa among which Ophiostoma piceae (Münch) Sydow & P. Sydow (10.3%), Alternaria alternata (Fries) Keissler (9.7%), Ogataea neopini Nagatsuka, S. Saito & Sugiyama (8.0%), Botryotinia fuckeliana (de Bary) Whetzel (5.1%), Cladosporium sp. Link (5.1%) and Sydowia polyspora (Brefeld & Tavel) E. Müller (4.6%) were the most common. Species of the genus Ophiostoma were the most abundant and included five different taxa O. piceae, O. bicolor R.W. Davidson & D.E. Wells, O. ips (Rumbold) Nannfeldt, O. canum (Münch) Sydow & P. Sydow and O. rectangulosporium Ohtaka, Masuya & Yamaoka, all of which are known to be at most weak pathogens of trees. The plant pathogen Botryotinia fuckeliana and insect pathogens Isaria farinose (Holmskjold) Fries and Beauveria bassiana (Balsamo-Crivelli) Vuillemin were also detected. Basidiomycetes were rare, among which three wood-decaying fungi Bjerkandera adusta (Willdenow) P. Karsten, Fomitopsis pinicola (Swartz) P. Karsten and Heterobasidion annosum (Fries) Brefeld were detected. In conclusion, in the forest-steppe zone in eastern Ukraine H. ligniperda is a vector of diverse communities of fungi the majority of which, if at all, are only weak pathogens of trees.

Development and thermal requirements of the Nearctic predator Geocoris punctipes (Hemiptera: Geocoridae) reared at constant and alternating temperatures and fed on Anagasta kuehniella (Lepidoptera: Pyralidae) eggs

Ana M. CALIXTO, Vanda H.P. BUENO, Flávio C. MONTES, Joop C. VAN LENTEREN

Eur. J. Entomol. 111 (4): 521, 2014 | DOI: 10.14411/eje.2014.074

Knowledge of the optimal temperatures for development and survival of biological control agents is essential for efficient mass-rearing and introduction of natural enemies in augmentative biological control programs. We studied the effect of constant and alternating temperatures on development and survival of immature stages and the sex ratio at emergence of adults of the Nearctic generalist predator Geocoris punctipes (Say). We also determined its thermal requirements. They were reared in climatic chambers at alternating (21/11°C, 24/18°C, 27/21°C and 30/26°C ± 1°C) and constant temperatures (16.8°C, 21.5°C, 24.5°C and 28.3°C ± 1°C), RH 70 ± 10% and a 14 h photophase. Survival and development of G. punctipes were the same when reared at constant and alternating temperatures. Five instars were recorded in all temperature regimes. The duration of the egg stage and each instar, as well as that of total larval development were longer, and larval survival lower when reared at 16.8°C, 21/11°C, 21.5°C and 24/18°C than at 24.5°C, 27/21°C, 28.3°C and 30/26°C. The optimal temperature range for development and survival of G. punctipes is 24.5°C to 30°C, its lower development threshold temperature is 13.5°C and its thermal constant 295.9 DD. Sex ratios were not significantly different from 1 : 1 male : female ratio in all temperature regimes. There is an excellent match between the temperature regimes at which the prey Tuta absoluta (Meyrick) and predator G. punctipes are active, which indicates that this predator will function well in crops where this pest is present.

Relationships between the geographic distribution of phytophagous insects and different types of vegetation: A case study of the flea beetle genus Chaetocnema (Coleoptera: Chrysomelidae) in the Afrotropical region

Maurizio BIONDI, Fabrizia URBANI, Paola D'ALESSANDRO

Eur. J. Entomol. 112 (2): 311-327, 2015 | DOI: 10.14411/eje.2015.040

This study analyses the geographic distributions of 95 endemic and sub-endemic species of Chaetocnema (Coleoptera: Chrysomelidae) found in Sub-Saharan Africa and Madagascar, in order to compare and correlate their pattern of the geographic range (chorotype) and the distribution of terrestrial ecosystems in Africa and Madagascar. The data compiled for the species of Chaetocnema are based on records for 1639 collecting localities. Most of the species of Chaetocnema have restricted geographical ranges (67.3%), whereas relatively few species (11.6%) are very widely distributed. The latitudinal and longitudinal gradients in the numbers of species reveal that the highest levels of species richness occur in the Equatorial Belt and Southern Africa. Species of Chaetocnema in Sub-Saharan Africa have a clear preference for grassland and the wide-open environment associated with savannah. However, forest ecosystems are also important for numerous species, particularly in Madagascar. Several endemic species are associated with the Mediterranean vegetation in the southern part of West Africa. Species of Chaetocnema are generally associated with a limited number of vegetation types within the Afrotropical region. A cluster analysis based on calculating the squared Euclidean distance and using the WARD clustering method revealed a significant correlation between the chorotype and the vegetation types associated with each species. Finally, certain species of Chaetocnema that are characteristic of specific types of vegetation and/or indicators of biodiversity hotspots in Sub-Saharan Africa and Madagascar are highlighted.

Hoverfly (Diptera: Syrphidae) richness and abundance vary with forest stand heterogeneity: Preliminary evidence from a montane beech fir forest

Laurent LARRIEU, Alain CABANETTES, Jean-Pierre SARTHOU

Eur. J. Entomol. 112 (4): 755-769, 2015 | DOI: 10.14411/eje.2015.083

Hoverflies (Diptera: Syrphidae) provide crucial ecological services and are increasingly used as bioindicators in environmental assessment studies. Information is available for a wide range of life history traits at the species level for most Syrphidae but little is recorded about the environmental requirements of forest hoverflies at the stand scale. The aim of this study was to explore whether the structural heterogeneity of a stand influences species richness or abundance of hoverflies in a montane beech-fir forest. We used the catches of Malaise traps set in 2004 and 2007 in three stands in the French Pyrenees, selected to represent a wide range of structural heterogeneity in terms of their vertical structure, tree diversity, deadwood and tree-microhabitats. We assessed hoverfly assemblages by recording species richness, abundance and functional diversity. Malaise traps caught 2,374 hoverflies belonging to 104 species. The catches of hoverflies fluctuated both in species richness and abundance between 2004 and 2007. Strictly forest species were only caught in the most heterogeneous stand. Species strictly associated with fir were not recorded in the least heterogeneous stand although fir was present. Although most of the functional groups were recorded in the three stands, species richness, abundance and functional diversity decreased dramatically from the most heterogeneous to the least heterogeneous stand. However, the species assemblages in the less heterogeneous stands were not perfect subsets of that in the most heterogeneous stand, as some additional species not found in the most heterogeneous stand were also present.

Seasonal polyphenism in Eristalis pertinax (Diptera: Syrphidae)Original article

Lukasz E. MIELCZAREK, Andrzej OLEKSA, Katarzyna MEYZA, Adam TOFILSKI

Eur. J. Entomol. 113: 489-496, 2016 | DOI: 10.14411/eje.2016.064

Eristalis pertinax varies seasonally, with the spring morph more hairy than the summer morph. We measured the size and the venation of the wings of the seasonal morphs. Wings of the spring morph were significantly larger than those of the summer morph and those of females were larger than those of males. There were also significant differences between the morphs in wing venation and their allometric relationship. The differences between sexes were larger than differences between seasonal morphs. The allometry can account for the sexual dimorphism but not seasonal dimorphism. The differences between seasonal morphs in wing shape were relatively large with very few intermediate individuals. The differences were comparable to those between two related species of Syrphidae. Genetic analyses based on markers in nuclear and mitochondrial genomes unequivocally revealed that spring and summer morphs of E. pertinax form a single population and should not be regarded as separate taxa. Thus seasonal variability in this species is a rare example of polyphenism in Diptera.

Effect of temperature on rate of development, survival and adult longevity of Phthorimaea operculella (Lepidoptera: Gelechiidae)Original article

Stefanos S. ANDREADIS, Christos G. SPANOUDIS, Georgia ZAKKA, Barbara ASLANIDOU, Sofia NOUKARI, Matilda SAVOPOULOU-SOULTANI

Eur. J. Entomol. 114: 35-41, 2017 | DOI: 10.14411/eje.2017.006

The potato tuberworm, Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae), is a major pest of potato, Solanum tuberosum L. (Solanales: Solanaceae), both in the field and storehouses. The rate of development and survival of P. operculella, reared on potato tubers cv. Spunta at eight constant temperatures (17.5, 20, 22.5, 25, 27.5, 30, 32.5 and 35°C), were studied in the laboratory. The duration of development of the immature stages was recorded. Adult longevity was also recorded under the same conditions. Developmental time decreased significantly with increase in temperature within the range 17.5-32.5°C. No development occurred at 35°C. Survival (%) from egg to adult was higher at temperatures within the range 17.5-27.5°C than at either 30 or 32.5°C. Linear and a non-linear (Logan I) models were fitted to our data in order to describe the developmental rate of the immature stages of P. operculella as a function of temperature and estimate the thermal constant (K) and critical temperatures (i.e., lower developmental threshold, optimum temperature for development, upper developmental threshold). Lower developmental threshold and optimum temperature for development ranged between 12.5-16.2 and 31.7-33.8°C, respectively. The estimated upper developmental threshold for total immature development was 35.0°C. Thermal constant for total development was 294.0 degree-days. Adult longevity was significantly shorter at high (30 and 32.5°C) than at low temperatures (17.5-27.5°C). Our results not only provide a broader insight into the thermal biology of P. operculella, but also can be used as an important tool in planning an effective pest control program both in the field and storehouses.

Improving knowledge of the subgenus Agrodiaetus (Lepidoptera: Lycaenidae: Polyommatus) in Eastern Europe: Overview of the Romanian faunaOriginal article

Vlad DINCĂ, Levente SZÉKELY, Zsolt BÁLINT, Marius SKOLKA, Sergiu TÖRÖK, Paul D.N. HEBERT

Eur. J. Entomol. 114: 179-194, 2017 | DOI: 10.14411/eje.2017.023

The butterfly subgenus Agrodiaetus of the genus Polyommatus (Lepidoptera: Lycaenidae) is distributed in the western and central Palaearctic and represents a taxonomically challenging group due to its rapid diversification coupled, in many cases, with very limited availability of morphological diagnostic characters. In this study we provide a detailed overview of this subgenus in the Romanian fauna, a country where scattered, poorly documented records suggest the presence of three species: Polyommatus (Agrodiaetus) damon, P. (A.) admetus and P. (A.) ripartii. By analyzing material from museum collections and published records, and combining them with new faunistic findings and DNA data, we show that only P. admetus is currently undoubtedly present in the Romanian fauna (northern Dobrogea), where it reaches its north-eastern range limit in the Balkans. Historical records and DNA data suggest that the occurrence of P. admetus in northern Dobrogea is not likely to reflect a recent range expansion caused by climate or other environmental changes. Several historical records of this species that suggest its much wider distribution in Romania represent confusion with P. damon and Phengaris alcon. Polyommatus damon, reported mainly from western Romania, lacks records after 1938, while P. ripartii is only known from a single male labelled as originating from the Danube Delta, and requiring confirmation. There is a great need for directed studies to clarify the status of P. damon and P. ripartii, which are scarce and declining north of the Balkans and may represent taxa of conservation concern.

Isolation and characterisation of the first microsatellite markers for the European stag beetle, Lucanus cervus (Coleoptera: Lucanidae)Note

Niall J. MCKEOWN, Deborah J. HARVEY, Amy J.E. HEALEY, Ilze SKUJINA, Karen COX, Alan C. GANGE, Paul W. SHAW

Eur. J. Entomol. 115: 620-623, 2018 | DOI: 10.14411/eje.2018.059

The European stag beetle, Lucanus cervus, is recognised as a flagship species for biodiversity conservation. Although the species is widely distributed across Europe declines have led to it being granted protected or endangered status in a number of countries and regarded as "near threatened" by the IUCN. The integration of genetic approaches into conservation efforts is urgently needed but has been impeded to date by the lack of appropriate genetic markers. To provide such a resource the development of the first microsatellite loci for stag beetle is described. Loci were identified using two methods (i) enriched library cloning (ELC) and (ii) Restriction enzyme Associated DNA sequencing (RAD-Seq). Inefficient microsatellite detection using the ELC method suggests that RAD-Seq, or other Next Generation Sequencing based methods, may ultimately be more cost effective for obtaining informative suites of markers for this and other coleopteran species. 18 loci were characterised by genotyping 42 UK specimens collected as prey leftover/roadkill. All loci produced unambiguous genotypes and were polymorphic. Though preliminary, estimates of genetic variability suggest UK populations may be genetically depauperate. The microsatellite loci represent a suite of genetic markers that can be applied to non-invasive population monitoring and numerous other areas of Lucanus conservation and evolutionary research.

Phylogeography of Trigonaspis synaspis (Hymenoptera: Cynipidae) from Anatolia based on mitochondrial and nuclear DNA sequences

Serap MUTUN, Gamze ATAY

Eur. J. Entomol. 112 (2): 259-269, 2015 | DOI: 10.14411/eje.2015.036

Sequence data for the nuclear ITS2 region and part of the mitochondrial cytochrome b gene were used to reveal intraspecific phylogeography and population genetic structure of the oak gall wasp Trigonaspis synaspis from Anatolia. One hundred and sixty six individuals representing 21 populations yielded 50 unique cyt b haplotypes and 15 ITS2 alleles. Genetic diversity estimates indicated the existence of high molecular variation, with average gene diversities of 0.85541 and 0.3119 for cyt b and ITS2 respectively. Likewise, nucleotide diversity was 0.01346 for cyt b and 0.0015 for ITS2. Pairwise divergence ranged from 0.2 to 3.1% between cyt b haplotypes, and from 0.2 to 2.8% between ITS2 alleles. Phylogenetic analyses of the cyt b haplotypes conducted using three different approaches produced mostly similar topologies, and major clades generally grouped haplotypes with similar geographic origins. Contrary to the mtDNA results, ITS2 analyses produced largely similar but polytomous topologies lacking apparent geographic structure. Application of the widely used insect mitochondrial molecular clock linked the origin of major phylogeographic structure to the effects of the Quaternary climatic oscillations. The outgroup haplotypes of T. megaptera are inferred to have diverged from T. synaspis around the late Pliocene. Intraspecific node ages in T. synaspis link major clade structure to the Pleistocene glacial cycles. Geographical formations in Anatolia were also probably an important factor in shaping the phylogeographic structure of T. synaspis.

The effect of hay mulching on soil temperature and the abundance and diversity of soil-dwelling arthropods in potato fieldsOriginal article

Péter DUDÁS, László MENYHÁRT, Csongor GEDEON, Gergely AMBRUS, Ferenc TÓTH

Eur. J. Entomol. 113: 456-461, 2016 | DOI: 10.14411/eje.2016.059

The average soil temperature was significantly lower in plots covered with hay. Hay mulching, however, did not increase significantly the total number of soil micro-arthropods collected using a soil pin trap and a soil sampler. Significant increases in the number of individuals was recorded only for certain groups. 64% of all the arthropods collected using soil pin traps were collected in hay-covered plots and 36% in control plots. This increase was statistically significant for the orders Entomobryomorpha and Poduromorpha of the subclass Collembola and surface-dwelling (epigeic) Coleoptera. For the samples collected using the soil sampler, 57% of the specimens were collected from hay-covered plots and 43% from control plots. As for the pin traps this was reflected in differences in the numbers of the orders Entomobrhyomorpha and Poduromorpha of the subclass Collembola and Pauropoda, collected in the treated and control plots. We conclude that mulching affected the different arthropod groups differently.

Adaptive significance of the prolonged diapause in the western Mediterranean lycaenid butterfly Tomares ballus (Lepidoptera: Lycaenidae)Original article

Rafael OBREGÓN, Juan FERNÁNDEZ HAEGER, Diego JORDANO

Eur. J. Entomol. 114: 133-139, 2017 | DOI: 10.14411/eje.2017.018

Diapause is a common dormancy strategy exhibited by many species of invertebrates and insects to temporarily avoid seasonally recurring unfavourable conditions for their development, most usually in winter. Less frequently, a prolonged diapause lasting two or more years is described in species living in unpredictable environments where it is adaptive, but with significant costs. In this paper we examine the occurrence of prolonged diapause in the lycaenid butterfly Tomares ballus. Pupae of this species undergo an obligate diapause from mid-May to late January the following year. However, during our rearing experiments (from 2009 to 2016) the emergence of adults occurred sequentially and a fraction of the pupae remained in diapause for up to seven years. The annual percentage emergence after the first year of diapause was 45.6%, and only barely exceeded 50.0% in 2015. Remarkably, 12 pupae (11.4% of the initial brood) remained in diapause in their eighth year. The negative exponential equation fitted to the emergence data suggests that further emergences may occur within the next five years. Therefore, the potential for successful prolonged diapause of T. ballus pupae may be more than 10 years. The adaptive value of this strategy is discussed in relation to the effects of adverse and unpredictable weather during the flight period of the butterfly, intra-guild competition, parasitoids and changes in habitat quality. We suggest that this strategy may also be exhibited by other species of Mediterranean lycaenids.

Acoustic signals of the bush-crickets Isophya (Orthoptera: Phaneropteridae) from Eastern Europe, Caucasus and adjacent territoriesOriginal article

Roustem ZHANTIEV, Olga KORSUNOVSKAYA, Alexander BENEDIKTOV

Eur. J. Entomol. 114: 301-311, 2017 | DOI: 10.14411/eje.2017.037

Temporal patterns and frequency spectra of the songs and stridulatory files of 14 species of the genus of the phaneropterid bush-crickets Isophya from Eastern Europe, Altai and the Caucasus are given. The sound signals of the species studied can be separated into three main types: (1) those consisting of two syllables (Isophya gracilis, I. kalishevskii, I. schneideri, I. caspica, Isophya sp. 1); (2) one syllable and series of clicks (I. modesta rossica, I. stepposa, I. taurica, I. brunneri, I. doneciana, I. altaica); (3) single repeating syllables of uniform shape and duration (I. pienensis, Isophya sp. 2 and possibly I. stysi). The acoustic signals and behaviour of eastern European, Altai and Caucasian species are compared to those of several other European species of Isophya.

Characterization and functional analysis of the serpin-10 gene from oak silkworm, Antheraea pernyi (Lepidoptera: Saturniidae)Original article

Saima KAUSAR, Cen QIAN, Muhammad Nadeem ABBAS, Bao-Jian ZHU, Ya LIU, Lei WANG, Guo-Qing WEI, Yu SUN, Chao-Liang LIU

Eur. J. Entomol. 114: 430-438, 2017 | DOI: 10.14411/eje.2017.055

Serpin is a broadly distributed superfamily of proteins that have a crucial role in regulating various immune reactions. Herein we identified a serpin-10 gene from Antheraea pernyi that encodes a 1557 amino acid residue protein with a predicted molecular weight of 58.76 kDa. Recombinant Apserpin-10 protein was expressed in a prokaryotic expression system (Escherichia coli) and the purified protein was used to prepare rabbit anti-Apserpin-10 polyclonal antibodies. Quantitative real-time polymerase chain reaction and western blot analysis indicate that Apserpin-10 was transcribed in all the tissues examined, including haemolymph, malpighian tubules, fat body, silk gland, integument and mid gut; the greatest expression level of Apserpin-10 was recorded in the fat body and haemocytes. The comparison of different developmental stages showed that Apserpin-10 transcript level was highest in 5th instar larvae, while the lowest expression was recorded at the egg stage. We also investigated the expression patterns of Apserpin-10 in fat body and haemocyte samples, following administration of heat-inactivated gram-positive bacteria (Micrococcus luteus), gram negative bacteria (Escherichia coli), a fungus (Beauveria bassiana) and virus (nuclear polyhedrosis virus, NPV). A substantial up-regulation of Apserpin-10 expression was recorded following pathogen challenge in both the tissues tested. Further the knock down of Apserpin-10 led to down regulation of antimicrobial peptide genes. Altogether, our results indicate that Apserpin-10 is involved in the innate immunity of A. pernyi.

Assessing genetic and morphological variation in populations of Eastern European Lucilia sericata (Diptera: Calliphoridae)Original article

Anna V. DIAKOVA, Dmitry M. SCHEPETOV, Nadezhda Y. OYUN, Anatole I. SHATALKIN, Tatiana V. GALINSKAYA

Eur. J. Entomol. 115: 192-197, 2018 | DOI: 10.14411/eje.2018.017

The population structures of different species of Calliphoridae flies are highly diverse at different locations. We investigated populations of the Eastern European L. sericata using chaetotaxy and eight microsatellite loci. Our results strongly indicate that a panmictic population of L. sericata exists in the area studied, possibly with a high rate of intra-population gene flow. Analysis of chaetotaxy also supports the panmictic population hypothesis.

Diversity of insects associated with two common plants in the Brazilian Cerrado: Responses of two guilds of herbivores to bottom-up and top-down forcesOriginal article

Juliana KUCHENBECKER, Marcílio FAGUNDES

Eur. J. Entomol. 115: 354-363, 2018 | DOI: 10.14411/eje.2018.035

The Trophic Cascade Theory has been used to explain the organization of herbivorous insect communities in tropical ecosystems. In addition, the insect community associated with a species of plant can also be determined by the geographical distribution and taxonomic isolation of the plant. In this study, the following predictions about the number of herbivores associated with particular host plants were tested: (i) plant species belonging to large taxonomic groups with broad geographical distributions have a higher number, (ii) the abundance of ants negatively affects herbivore insect diversity, (iii) local plant diversity positively affects chewing herbivore diversity and (iv) local abundance of a specific host plant positively affects the diversity of sucking herbivores. The samples of insect herbivores were collected from 32 plants (16 plants of Erythroxylum suberosum and 16 of Qualea parviflora) by beating. A total of 71 ants (13 species) and 158 herbivorous insects (90 species) were collected from these two species of plants. The richness and abundance of the insect herbivores collected from E. suberosum differed from those collected from Q. parviflora. The abundance of ants negatively affected the diversity of sucking insects associated with E. suberosum. In addition, the interaction between the variables total plant richness per plot and ant abundance affected the diversity of chewing insects associated with E. suberosum. The density of Q. parviflora per plot affected the diversity of associated sucking insects. In addition, the interaction of the variables abundance of ants and abundance of Q. parviflora influenced the diversity of chewing insects. Our results indicate that there is no predominance of bottom-up or top-down forces in the organization of herbivorous insect communities in this area of tropical savanna, but the roles of these forces on insect communities are guild-dependent.

 previous    ...   9   10   11   12   13  14   15   16   17   18   ...    next