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Results 421 to 450 of 1442:

Size-related mortality during overwintering in cavity-nesting ant colonies (Hymenoptera: Formicidae)Original article

S³awomir MITRUS

Eur. J. Entomol. 113: 524-527, 2016 | DOI: 10.14411/eje.2016.070

The ongoing process of climate change will result in higher temperatures during winter and therefore might increase the survival of overwintering invertebrates. However, the process may also lead to a reduction in snow cover and expose overwintering invertebrates to lower temperatures, which could result in higher mortality. During a field experiment, I investigated the effects of a reduction in snow cover on the survival of the ant Temnothorax crassispinus, which overwinters in nests located on the ground. Ant colonies differed in the survival rate of the workers in the experimental (from which snow cover was removed) and control group. In the control group, the survival rate was unrelated to colony size. However, in the experimental group, from which snow was removed after each heavy snowfall, worker survival was lower in small colonies. Such colony size related mortality may affect the fusion of colonies before winter.

A new suite of twenty-two polymorphic microsatellite loci in the parasitic wasp, Habrobracon hebetor (Hymenoptera: Braconidae): Promising molecular tools for studying the population genetics of several beneficial braconid speciesNote

Madougou GARBA, Anne LOISEAU, Laure BENOIT, Nathalie GAUTHIER

Eur. J. Entomol. 113: 265-269, 2016 | DOI: 10.14411/eje.2016.031

Combining a biotin-enrichment protocol and 454GS-FLX titanium pyrosequencing technology, we characterised 22 polymorphic microsatellite loci from the parasitic wasp, Habrobracon hebetor (Say) (Hymenoptera: Braconidae), a cosmopolitan species commonly used in biological control against a wide range of both major lepidopterous pests of stored products and field crops in different parts of the world. Three multiplex PCR sets were optimised and characterised across 46 H. hebetor specimens from two samples collected from millet fields in Niger. Two to 11 alleles were found per locus and observed heterozygosity ranged from 0.289 to 0.826. Polymorphism was detected in both samples with a similar level of observed heterozygosity (0.482 vs. 0.502) and number of alleles (4.1 vs. 3.6). Deviation from Hardy-Weinberg equilibrium was detected at the same five loci in both samples and five or seven more loci in each sample but was not associated with heterozygote deficiencies. Even though evidence for linkage disequilibrium was found between a few alleles, these new loci segregated independently. The variability of the 22 loci will enable estimates of genetic diversity and structure patterns, as well as gene flow between H. hebetor populations at different spatial scales. Cross-species amplifications were successful among the six Bracon spp. tested and nine loci will be particularly appropriate for population genetic studies in B. brevicornis.

The mitochondrial genome of the Mediterranean flour moth, Ephestia kuehniella (Lepidoptera: Pyralidae), and identification of invading mitochondrial sequences (numts) in the W chromosomeOriginal article

Katrin LÄMMERMANN, Heiko VOGEL, Walther TRAUT

Eur. J. Entomol. 113: 482-488, 2016 | DOI: 10.14411/eje.2016.063

The Mediterranean flour moth, Ephestia kuehniella is a widespread pest of stored products and a classical object in experimental biology. In the present study, we determined its complete mitochondrial genome sequence. The genome is circular, consists of 15,327 bp and comprises 13 protein-coding, 2 rRNA- and 22 tRNA-coding genes in an order typical for the Ditrysia clade of the order Lepidoptera. A phylogenetic study of the Lepidoptera based on complete mitochondrial genomes places E. kuehniella correctly in the family Pyralidae and supports major lepidopteran taxa as phylogenetic clades. The W chromosome of E. kuehniella is an exceptionally rich reservoir of originally mitochondrial sequences (numts). Around 0.7% of the W DNA was found to be of mitochondrial origin, 83% of the mitogenome sequence was represented between 1-11 × in the W chromosome. Phylogenetic analysis further revealed that these numts are an evolutionary recent acquisition of the W chromosome.

Trophobiosis in the arboricolous ant Liometopum microcephalum (Hymenoptera: Formicidae: Dolichoderinae)

Jiøí SCHLAGHAMERSKÝ, Jan KA©PAR, Lenka PETRÁKOVÁ, Vladimír ©USTR

Eur. J. Entomol. 110 (2): 231-239, 2013 | DOI: 10.14411/eje.2013.033

The arboricolous dolichoderine ant Liometopum microcephalum (Panzer, 1798) is considered to be mainly predatory, although there are some reports of it tending aphids. The main objective of the present study was to confirm that this ant has a trophobiotic relationship with aphids and assess seasonal differences in its utilization of honeydew. We hypothesized that the worker ants on trees where they have their nest (nest tree) and trees where they are foraging (foraging trees) should differ in gaster mass and sugar content depending on their direction of movement, and that both should be highest in spring. From spring to summer 2009, ascending and descending workers were collected from nest and foraging trees at a locality in South Moravia, Czech Republic. Mass of their gasters and their content of total and reducing sugars were measured using chemical (photometric) methods. Differences in gaster mass confirmed the flow of liquid food from foraging to nest trees, but there were no significant between-month differences. Contents of total and reducing sugars were positively correlated with gaster mass. The gasters of workers descending from foraging trees contained significantly more reducing sugars than those of workers descending or ascending nest trees. The content of reducing sugars was lowest at the beginning of the ants' activity period in April and highest in June, with a non-significant drop in July. Results for total sugars were similar, with the decrease in July being significant. The concentration of sugars in the gasters of workers ascending and descending nest trees did not differ significantly but the absolute content of total sugars was higher in the gasters of ascending ants. Results from foraging trees confirmed that the ants collected the honeydew from these trees. Possible reasons for the ambigous results for nest trees are discussed. We conclude that trophobiosis is an important component of the nutritional biology of L. microcephalum.

Phenological responses of Pseudomallada (Neuroptera: Chrysopidae): Comparative data from three Nearctic species and interspecific hybrids

Maurice J. TAUBER, Catherine A. TAUBER

Eur. J. Entomol. 112 (1): 49-62, 2015 | DOI: 10.14411/eje.2015.015

Three Nearctic species - Pseudomallada macleodi (Adams & Garland), P. perfectus (Banks), and P. sierra (Banks) - share a suite of phenological characteristics with their Western Palearctic congeners. They overwinter as free-living larvae (primarily third instars) in a photoperiodically induced diapause. For these three species, the critical photoperiods for diapause induction fell between LD 16:8 and LD 14:10. In the laboratory, larvae remained responsive to daylength throughout diapause - short daylengths maintained diapause until diapause terminated spontaneously or death occurred. Transfer of diapausing larvae from short to intermediate or longer days accelerated diapause development, apparently in a quantitative response to daylength. A period of chilling appeared to delay, rather than hasten, diapause development. In general, the expression of diapause in F1 hybrids (P. perfectus × P. sierra) resembled that of the parents; there were minor differences in some features. Among populations of the three species under non-diapause conditions, the times for complete development (egg hatch to adult emergence) ranged between 40 and 50 days (23.9°C). Under long-day conditions, developmental rates of the P. perfectus egg and prepupal-pupal stages were linearly related to temperature; we provide thermal thresholds and heat-degree days for these stages. In contrast, developmental rates of free-living larvae did not have a linear relationship with temperature; photoperiod may interact with temperature to affect non-diapause development in these stages.

Feeding and oviposition behaviour of a gall inducing species of Glycaspis (Synglycaspis) (Hemiptera: Psylloidea: Aphalaridae) and development of galls on the leaves of Eucalyptus macrorhyncha (Myrtaceae) in central western New South Wales, Australia

Anamika SHARMA, Anantanarayanan RAMAN, Gary S. TAYLOR, Murray J. FLETCHER, Helen I. NICOL

Eur. J. Entomol. 112 (1): 75-90, 2015 | DOI: 10.14411/eje.2015.021

Glycaspis (Synglycaspis) confined to Australia includes gall-inducing and lerp-forming species that are probably highly specific to different species of Eucalyptus subgenus Eucalyptus. Based on available information, their distribution appears restricted to temperate, south-eastern and southern Australia. This paper reports the biology of an unnamed (suspected new species) of Glycaspis (Synglycaspis) that induces spherical, ostiolate galls on the leaves of Eucalyptus macrorhyncha in central western tablelands of NSW. This species completes two generations in a year. Oviposition elicits a passive response in the leaves of E. macrorhyncha. In this work we demonstrate that the host tissue not only supplies water, but also nutrients to the developing embryo via the embedded pedicel. Feeding action of the first instar initiates the gall and morphogenetic gradients become apparent around the feeding site. These gradients direct gall growth. The gall attains its near final spherical shape during the second instar and this spherical gall remains plugged with sugary material, which all the immature stages secrete from the last abdominal segment. No significant gall growth occurs during the occupation of the gall by the third, fourth and fifth instars. The first and second instars feed on the newly differentiated parenchyma tissue in galls, whereas the third, fourth and fifth instars feed on phloem of galls. Consequently the multi-layer parenchymatous nutritive tissue that initially develops lining the chamber dries and shrivels, when the later instars inhabit galls. This shrinkage induces a gradual thinning of gall walls, which is also aggravated by modest expansive growth of the gall.

Ultrastructural and biochemical comparison of summer active and summer diapausing pupae of the horse chestnut leaf miner, Cameraria ohridella (Lepidoptera: Gracillariidae)

Franti¹ek WEYDA, Jitka PFLEGEROVÁ, Tereza STA©KOVÁ, Ale¹ TOMÈALA, Eva PRENEROVÁ, Rostislav ZEMEK, Lubomír VOLTER, Dalibor KODRÍK

Eur. J. Entomol. 112 (1): 197-203, 2015 | DOI: 10.14411/eje.2015.014

The ultrastructural and biochemical characteristics were studied in active and diapausing pupae of the horse chestnut leaf miner, Cameraria ohridella, collected in summer. The active pupae contained developing internal organs, while those in diapause mostly numerous non-differentiated cells packed with stored nutrients. These nutrients occurred in vacuoles as liquid material (lipids, proteins) or as reserve crystaloids (proteins). Triacylglycerols (TGs) were the main lipids stored by pupae and were more abundant in diapausing than active pupae. The amount of diacyglycerols (DGs) and phospholipids (PLs) was almost identical in both groups, which reflects the roles of these compounds in lipid transport and structure of cell membranes, respectively. A principal component analysis (PCA) indicated differences in the quality of the lipid compounds in both groups and that the TGs were mostly responsible for the difference. Polyunsaturated linolenic acid (18 : 3) was the most abundant fatty acid in both active and diapausing pupae, nevertheless its content was significantly higher in the former; the level of 7 fatty acids reached values higher than 1%. Differences in other nutrients were similar to those of TGs; higher contents of both glycogen and proteins were recorded in diapausing than active pupae. The results revealed significant differences between the two summer pupal forms of C. ohridella and furthered our understanding of the developmental strategy of this successful, invasive pest insect.

Age dependent mate choice influences reproductive and progeny attributes in aphidophagous ladybird beetles (Coleoptera: Coccinellidae)

Mahadev BISTA, OMKAR

Eur. J. Entomol. 112 (4): 648-657, 2015 | DOI: 10.14411/eje.2015.082

Despite the many studies on age based mate choice in insects, the question of how age influences mate choice in predaceous ladybird beetles is still unexplored. The present study evaluates age based mate choice in two sympatric aphidophagous ladybirds, Coccinella septempunctata L. and Coccinella transversalis Fab., in terms of mating behaviour (latent period, number of bouts, bout interval and duration of wriggling movements and mating), fecundity, egg viability and the development and survival of their progeny. Results revealed that middle aged (30-40 days) mates were preferred by young (10-15 days post-eclosion), middle aged (30-40 days) and old (45-55 days) individuals of both sexes. Mating behaviour and egg viability differed significantly with male age whereas fecundity, offspring development and survival differed significantly with female age. The shortest latent periods and bout intervals, highest numbers of bouts, longest durations of wriggling movements and mating, and maximum egg viability were recorded for middle aged males whereas fecundity, percentage pupation and adult emergence of offspring were highest and durations of immature development were shortest for middle aged females. Thus, the present study indicates that middle aged individuals of C. septempunctata and C. transversalis are most preferred as mates as they have the highest reproductive output and produce the fittest offspring.

Depilation increases while hairiness decreases the risk of drowning: A hitherto unappreciated survival role of setae in woolly bear caterpillars of the moth Lemyra imparilis (Lepidoptera: Noctuoidea: Erebidae)Note

V. Benno MEYER-ROCHOW

Eur. J. Entomol. 113: 130-134, 2016 | DOI: 10.14411/eje.2016.016

This note aims to put on record a hitherto unreported function of caterpillar setae supplementary to those already known. When woolly bear caterpillars of the moth Lemyra imparilis (Butler) have their body hairs removed and are dropped into a bucket of water from a height of 30 cm, they sink immediately. Caterpillars, however, with an intact coat of hairs usually float. This hitherto unreported role of caterpillar setae as life-rafts should depend on a high contact angle θe, and thus on the position, density and dimensions of the hairs. An SEM examination of the surface structure of the setae revealed a system of fine grooves and small distally pointing barbs on the hair shaft, which can trap air to support the weight of the insect. Insect setae generally and body hairs of caterpillars in particular are known to possess many functions, but a role as life-rafts for caterpillars in danger of drowning can now be added to the list of possible uses of body hairs.

Generalist-specialist continuum and life history traits of Central European butterflies (Lepidoptera) - are we missing a part of the picture?

Alena BARTONOVA, Jiri BENES, Martin KONVICKA

Eur. J. Entomol. 111 (4): 543-553, 2014 | DOI: 10.14411/eje.2014.060

Abstract. Analyzing life history traits of butterfly communities and faunas frequently reveals a generalist-specialist continuum as the main gradient, where species using wide arrays of resources, with good dispersal ability and fast development are distinguished from those using specialised resources, having limited dispersal ability and developing slowly. To ascertain the validity of the generalist-specialist approach for an intermediately species-rich Central European fauna, we analyzed ten life history traits for 136 species of butterflies currently occurring in the Czech Republic, using principal correspondence analysis (PCA) and controlling for phylogeny. The main gradient extracted indeed revealed a generalist-specialist continuum, while the gradient perpendicular to the main axis distinguished between small-bodied polyvoltine species feeding on small herbaceous plants and large-bodied monovoltine species feeding on grasses or woody plants. We coin "constrained voltinism continuum" for the second gradient and argue that it reflects the effect of anti-herbivore strategies of larval host plants on butterfly development. The position of the butterflies in the PCA ordination mirrors the C-S-R (Competitors - Stress tolerators - Ruderals) strategies of their host plants. Butterflies that feed on C- and R-selected plants tend to be generalists, but differ in voltinism, whereas specialists tend to feed on S-selected plants. Regressing measures of current conservation status of individual species in the Czech Republic against the two extracted life history gradients yielded a significant but weak response for the generalist-specialist continuum and no response for the constrained voltinism continuum. The weak responses were due to a wide scatter of status measures among "mid generalists". The generalist-specialist continuum is hence a rather poor predictor of species conservation status. Species of high conservation concern are found either among specialists, or among mid generalists with low to intermediate values on the constrained voltinism axis.

Feeding of Scydmaenus rufus (Coleoptera: Staphylinidae: Scydmaeninae) on oribatid and uropodine mites: Prey preferences and hunting behaviour

Pawe³ JA£OSZYÑSKI, Ziemowit OLSZANOWSKI

Eur. J. Entomol. 112 (1): 151-164, 2015 | DOI: 10.14411/eje.2015.023

Prey preferences and feeding-related behaviour of a Central European species of Scydmaeninae, Scydmaenus rufus, were studied under laboratory conditions. Results of prey choice experiments involving 22 identified species of mites belonging to 13 families of Oribatida and two families of Mesostigmata (Uropodina) demonstrated that this beetle feeds mostly on oribatid Scheloribatidae (60.38% of prey) and Oppiidae (29.75%) and only occasionally on uropodine Urodinychidae (4.42%) and oribatid Mycobatidae (3.39%); species belonging to Trematuridae (Uropodina), Ceratozetidae and Tectocepheidae (Oribatida) were consumed occasionally. The number of mites consumed per beetle per day was 1.42, and when Oppia nitens was the prey, the entire feeding process took 2.93-5.58 h. Observations revealed that mechanisms for overcoming the prey s defences depended on the body form of the mite. When attacking oribatids, with long and spiny legs, the beetles cut off one or two legs before killing the mite by inserting one mandible into its gnathosomal opening. Flattened and short-legged uropodines were killed in the same way but without cutting off their legs. More legs of the prey were removed during feeding, when the mite was already dead; in Oribatida additional damage included removal of genital plates, whereas the genital structures remained intact in Uropodina. Scydmaenus rufus was able to feed on potentially highly toxic Scheloribatidae, which raises questions about the efficiency of chemical defence in Oribatida.

Wing morphology is linked to stable isotope composition of nitrogen and carbon in ground beetles (Coleoptera: Carabidae)

Marcin ZALEWSKI, Dorota DUDEK-GODEAU, Alexei V. TIUNOV, Jean-François GODEAU, Yutaka OKUZAKI, Hiroshi IKEDA, Pawe³ SIENKIEWICZ, Werner ULRICH

Eur. J. Entomol. 112 (4): 810-817, 2015 | DOI: 10.14411/eje.2015.072

As movement is expensive in terms of energy required, mobile animals might have to utilize more energy rich resources than less mobile animals. As mobile animals are possibly more effective foragers we hypothesize a positive correlation between mobility and trophic niche width. We address this link using information on the trophic level of 35 winged, wingless and wing dimorphic species of ground beetles studied on 18 lake islands and at two mainland sites in northern Poland. Trophic analyses using stable isotope values (δ15 N, δ13C) revealed that winged individuals of wing dimorphic species are characterized by broader isotopic niches than wingless individuals. Macropterous species are characterized by depleted δ13C values, which can be interpreted in terms of lipid-rich prey selection. Wing dimorphic species are characterized by higher trophic levels, as inferred from δ15 N values, than winged species. Numbers of islands colonized by particular species were not correlated with δ15 N values, δ13C values or isotopic niche width. Our results point to a relationship between diet and wing morphology in ground beetles.

Tettigoniidae (Orthoptera) ovipositing in old galls of Dryocosmus kuriphilus (Hymenoptera: Cynipidae)Note

Giuliano CERASA, Bruno MASSA

Eur. J. Entomol. 113: 397-402, 2016 | DOI: 10.14411/eje.2016.051

This paper presents biological notes on two species of Orthoptera: Tettigoniidae that emerged from old spongy-woody galls of Dryocosmus kuriphilus Yasumatsu, 1951 collected in Sicily (Italy) in April 2015: Leptophyes sicula Kleukers, Odé et Fontana, 2010 (Phaneropterinae) and Cyrtaspis scutata (Charpentier, 1825) (Meconematinae). Between the end of April and the first few days of May a total of 30 neanids emerged from the galls, were reared and their life-cycle recorded. While L. sicula laid eggs in groups, C. scutata laid single eggs inside the galls; both species in a few years have adapted to exploiting this new shelter for egg laying. No interaction with the gall inducing insect was noted.

Comparative efficiency of traps for horse fly (Diptera: Tabanidae) survey in riparian oak-ash forests in Danube floodplainOriginal article

Alma MIKU©KA, Selma MLINARIÆ, Lidija BEGOVIÆ, Erin CURRAN

Eur. J. Entomol. 113: 531-536, 2016 | DOI: 10.14411/eje.2016.072

The objective of this work was to evaluate the relative trap efficiency of the three modified traps baited with 1-octen-3-ol as attractant, Box, Nzi and Canopy, for horse fly (Tabanidae) survey. Nine traps (three traps per trap type) were tested in 3 × 3 Latin square designs during summer 2011 in riparian oak-ash forests in the Danube floodplain of Croatia. Overall, the traps caught 1,986 specimens of 11 horse flies species during the study period. The most abundant species caught was Tabanus bromius (58%), followed by Tabanus tergestinus (21%), Tabanus maculicornis (16%), Tabanus sudeticus (2%), Atylotus loewianus (1%) and Tabanus autumnalis (1%). Both the Box traps and the Nzi traps had significantly greater catch efficiencies than the Canopy traps (βbox = 2.47, X2 = 65.48, df = 1, P < 0.001 and βnzi = 1.54, X2 = 25.12, df = 1, P < 0.001, respectively). Nzi traps had a catch rate 4.65 (95% CI: 2.55, 8.48) times greater than Canopy traps and Box traps had a catch rate 11.77 (95% CI: 6.48, 21.39) times greater than Canopy traps. Based on Shannon-Wiener diversity indices Nzi traps were better suited for diversity survey and had higher (H' = 1.33) indices than Box (H' = 1.08) or Canopy traps (H' = 1.00).

Occurrence of Harmonia axyridis (Coleoptera: Coccinellidae) in field crops

Axel VANDEREYCKEN, Yves BROSTAUX, Emilie JOIE, Eric HAUBRUGE, François J. VERHEGGEN

Eur. J. Entomol. 110 (2): 285-292, 2013 | DOI: 10.14411/eje.2013.042

The Multicoloured Asian Ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is known to thrive principally in shrubby and arboreal habitats. This study focuses on the occurrence of this exotic species and its seasonal abundance in various field crops. The abundance of adults, larvae and pupae of H. axyridis was evaluated over a three-year period, from 2009 to 2011, in four important agronomical crops (wheat, corn, broad bean and potato) in Belgium. From May to September, 48 1-m2 quadrats were visually inspected in each of the fields sampled on several farms every seven days. H. axyridis colonized and reproduced in all of the four crops studied, with the largest numbers recorded in corn and broad bean crops. Larvae and adults of H. axyridis were recorded mainly in corn and to a much less extent in wheat and potato crops. From 2009 to 2011, the mean weekly abundance of H. ayxridis remained constant except in corn crops, where the recorded densities of all the immature stages and adults were higher in 2011 than in 2009. The population dynamics of aphids and H. axyridis are well described by a symmetric logistic function (S-shape) of cumulative population size. H. axyridis was not always recorded where aphids were abundant, e.g. aphids were abundant on wheat where no H. axyridis were recorded. H. axyridis start reproducing after the peak in aphid population, suggesting that H. axyridis is able to complete its development by feeding on alternative prey such as larvae and pupae of the same and other species of ladybird and other aphidophagous species. H. axyridis is often considered to be bivoltine but it only completes one generation per year in field crops. The second generation generally develops late in the season in other habitats.

Spatial ecology of Hydropsyche incognita (Trichoptera: Hydropsychidae) in the Carpathians

Mãlina PÎRVU, Claudia ZAHARIA, Alina SATMARI, Lucian PÂRVULESCU

Eur. J. Entomol. 112 (1): 106-113, 2015 | DOI: 10.14411/eje.2015.006

Caddisflies are often used in studies on freshwater ecosystem ecology because of their aquatic-dependent larvae. The present study addresses the ecological affinities of larvae of Hydropsyche incognita in terms of the pattern of distribution of this species in the Romanian Carpathians using a boosted regression trees (BRT) model. A population cluster located in the western Romanian Carpathians was identified by the spatial analysis. The statistical model revealed that this species prefers a neutral to low-alkaline pH, high levels of dissolved oxygen, low conductivity, fast flowing water, moderate sized rivers at an altitude below 600 m a.s.l. and low concentrations of organic pollutants. An eastward decrease in the frequency of H. incognita populations was recorded along rivers in the Carpathians. The predictions derived from the BRT model on sites outside the population cluster suggest that many locations in the central and eastern Romanian Carpathians are suitable for H. incognita. However, this species was found at only a few of these locations. In contrast, some populations in this area were found in habitats predicted as unsuitable. There are several possible explanations of this, one of which is random dispersion of the species by flying adults.

A revision of the cleptoparasitic bee genus Coelioxys (Hymenoptera: Megachilidae) from AustraliaOriginal article

Léo Correia da ROCHA-FILHO

Eur. J. Entomol. 113: 9-28, 2016 | DOI: 10.14411/eje.2016.002

The Australian species of the genus Coelioxys Latreille are revised. Six species are recognized: Coelioxys albolineata Cockerell, 1905; Coelioxys froggatti Cockerell, 1911; Coelioxys reginae Cockerell, 1905; Coelioxys weinlandi Schulz, 1904 and two new species: Coelioxys julia sp. n. and Coelioxys tasmaniana sp. n. Three names are synonymized: Coelioxys biroi Friese, 1909 syn. n. and Coelioxys albolineata darwiniensis Cockerell, 1929 syn. n. under Coelioxys albolineata, and Coelioxys victoriae Rayment, 1935 syn. n. under Coelioxys froggatti. Species descriptions and redescriptions, illustrations, distribution maps, floral records and a key to both sexes of all species are provided.

Effect of three species of host tree on the cold hardiness of overwintering larvae of Anoplophora glabripennis (Coleoptera: Cerambycidae)Original article

Yuqian FENG, Reaxit TURSUN, Zhichun XU, Fang OUYANG, Shixiang ZONG

Eur. J. Entomol. 113: 212-216, 2016 | DOI: 10.14411/eje.2016.026

The Asian long-horned beetle, Anoplophora glabripennis, is a serious destructive pest of forests throughout China as it attacks a wide range of host plants. The effect of host trees on the cold hardiness of A. glabripennis larvae could be the basis for predicting the performance of this forest pest on different common hosts.To evaluate the effect of different species of host plant on the cold hardiness of overwintering larvae of A. glabripennis, we measured the supercooling point (SCP), fresh mass, protein content and concentrations of low molecular weight substances in overwintering larvae collected from three different host species (i.e., Populus opera, Populus tomentosa and Salix matsudana). Mean SCPs and protein contents of larvae from these three hosts differed significantly. The SCPs and protein contents of the larvae collected from P. opera and P. tomentosa were significantly higher than those collected from S. matsudana. The concentrations of glycerol, glucose and trehalose in overwintering larvae collected from these host species also differed significantly, but there were no significant differences in the concentrations of sorbitol and inositol. The larvae that were collected from S. matsudana had the highest concentrations of glycerol and trehalose and those from P. opera the lowest contents of glycerol, whereas those from P. tomentosa had the lowest concentrations of trehalose but the highest concentrations of glucose. Because of the significant differences in the quantities of these biochemical substances in their bodies, the cold hardiness of overwintering larvae of A. glabripennis was significantly dependent on the tree they fed on. These effects on the cold hardiness of the overwintering larvae might affect the selection of a host tree and therefore the spread of this beetle.

Identification and abiotic stress response of a glutamine synthetase gene (AccGS) from the Asiatic honeybee, Apis cerana cerana (Hymenoptera: Apidae)

Xiuling WANG, Yuzhen LI, Yan YAN, Baohua XU, Xingqi GUO

Eur. J. Entomol. 111 (1): 1-9, 2014 | DOI: 10.14411/eje.2014.001

Glutamine synthetase (GS) is an essential detoxification enzyme that plays an important role in stress responses; however, little information regarding the function of this enzyme in hymenopteran insects is available. In the present study, we isolated and characterized the gene encoding GS in the Asiatic honeybee, Apis cerana cerana. Multiple alignments and a phylogenetic analysis of GS sequences showed that AccGS belongs to the GSII superfamily and clusters with invertebrate GSs. Real-time quantitative PCR data demonstrated that AccGS is expressed at all developmental stages and in all tissues, with the highest expression observed in the sixth larval instar and in the brain. Moreover, AccGS expression is highly regulated by environmental stress, including xenobiotic, temperature, and ultraviolet light stresses. A disc diffusion assay showed that the recombinant AccGS protein confers resistance to mercuric chloride (HgCl2) stress in E. coli. This suggests that AccGS may play multiple roles in early development and in environmental stress responses.

Benign neglect enhances urban habitat heterogeneity: Responses of vegetation and carabid beetles (Coleoptera: Carabidae) to the cessation of mowing of park lawns

Stephen VENN, D. Johan KOTZE

Eur. J. Entomol. 111 (5): 703-714, 2014 | DOI: 10.14411/eje.2014.089

In this study, we investigate the changes in both vascular plant and carabid beetle assemblages in response to reducing the intensity of management of park lawns in the city of Helsinki. Three levels of mowing were applied to patches of previously managed park lawns: (1) intensively mown, (2) mown until the previous season and unmanaged since, and (3) unmanaged for ten years (benign neglect). The lawns were dominated by plants that disperse vegetatively. This treatment gradient had little or no effect on the flight capability, feeding type or body-size of carabid beetles. However, there was an increase in species richness and the numbers of stenotopic species in the benign neglect treatment. We conclude that benign neglect of open grassland vegetation will result in higher levels of biodiversity than in more intensely managed vegetation. However, we consider it likely that the optimal strategy for maintaining urban biodiversity would be to apply a meadow management regime of mowing once or twice per year and leaving some areas of unmanaged grassland to maintain habitat heterogeneity.

Book review: Vega F.E. & Hofstetter R.W. (eds) 2015: Bark Beetles: Biology and Ecology of Native and Invasive Species, 1st ed.Book review

M. KNͮEK

Eur. J. Entomol. 113: 307-308, 2016 | DOI: 10.14411/eje.2016.038

Vega F.E. & Hofstetter R.W. (eds) 2015: Bark Beetles: Biology and Ecology of Native and Invasive Species, 1st ed. Elsevier, Academic Press, Amsterdam, Boston, Heidelberg, London, New York, Oxford, Paris, San Diego, San Francisco, Singapore, Sydney, Tokyo, 640 pp. ISBN 9780124171565. Price EUR 92.95.

Electrophysiological and oviposition responses of Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae), to compounds rinsed from the surfaces of sugarcane and maize leaves

Xing-Chuan JIANG, Wen-Xia DONG, Bin CHEN, Chun XIAO, Fu-Rong GUI, Nai-Sheng YAN, Lei QIAN, Zheng-Yue LI

Eur. J. Entomol. 112 (2): 295-301, 2015 | DOI: 10.14411/eje.2015.042

The Asian corn borer, Ostrinia furnacalis, is one of the most important pests of maize (Zea mays) in China. However, the mechanism by which intercropping sugarcane (Saccharum officinarum) and maize controls this pest via compounds rinsed from leaf surfaces is still unclear. Electrophysiological and oviposition responses of the Asian corn borer to compounds rinsed from leaf surfaces of sugarcane and maize were studied. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses revealed that O. furnacalis responds to 21 compounds, which are present in both the compounds rinsed from leaf surfaces of sugarcane and maize. The effects of these compounds in concentrations of 5 × 10-3 g/mL or 5 × 10-4 g/mL on female oviposition behaviour were tested. They were attracted to oviposit on substrates coated with most of the test compounds, except nonanal. It is suggested that the compounds from the leaf surfaces of sugarcane induced O. furnacalis females to oviposit because most of them are similar to maize's leaf surface compounds, which results in a reduction in the number of egg masses laid on maize leaves.

Identification of microsatellite markers for a worldwide distributed, highly invasive ant species Tapinoma melanocephalum (Hymenoptera: Formicidae)Note

Jan ZIMA Jr., Ophélie LEBRASSEUR, Michaela BOROVANSKÁ, Milan JANDA

Eur. J. Entomol. 113: 409-414, 2016 | DOI: 10.14411/eje.2016.053

Tapinoma melanocephalum is a worldwide distributed, highly invasive ant species. It lives in close association with human societies and its distribution is human-mediated in large measure. The geographical origin of this ant species is unknown, but its introduction in areas previously devoided of its presence can represent a threat to the native biota, act as an agricultural pest or as a pathogen vector. To investigate the genetic structure and phylogeography of this species we identified 12 new polymorphic microsatellite markers, and in addition, we tested and selected 12 ant-universal microsatellites polymorphic in T. melanocephalum. We genotyped 30 individuals from several islands of Micronesia and Papua-New Guinea. All 24 loci exhibited strong homozygosity excess (45-100%, mean = 86%), while the number of alleles per locus reached usual values (2-18, mean = 6.5), resulting in levels of expected heterozygosity much higher than observed. Based on several robust tests, we were able to exclude artefacts such as null alleles and allelic dropout as a possible cause of the observed pattern. Homozygosity excess might be a consequence of founder effect, bottleneck and/or inbreeding. As our sample population was composed of individuals from several distinct localities, the Wahlund effect might have contributed to the increased homozygosity as well. Despite the provisionally observed deviation from the Hardy-Weinberg equilibrium, the newly developed microsatellites will provide an effective tool for future genetic investigations of population structure as well as for the phylogeographic study of T. melanocephalum.

Do sexually dimorphic glands in the harvestman Gryne perlata (Arachnida: Opiliones) release contact pheromones during mating?Original article

Jéssica M. DIAS, Rodrigo H. WILLEMART

Eur. J. Entomol. 113: 184-191, 2016 | DOI: 10.14411/eje.2016.022

There are records of glands that produce sexual pheromones that are released into the environment or applied directly on sexual partners. Within Opiliones (Arachnida), several harvestmen in the suborder Laniatores have sexually dimorphic glands on legs I and IV, the mode of use of which is recorded only in two species but their function is unknown: while walking, males rub the glands against the substrate or against their body. Here we test an alternative and non-exclusive hypothesis that the glands present on the legs of male Gryne perlata (Cosmetidae) produce contact pheromones used in mating. We predicted that males would touch the females with the gland openings or with other male body parts previously rubbed by these glands. We also predicted that there are chemoreceptors on those parts of the females where males touch them. We analyzed 13 videos of G. perlata mating, a species in which the males have glands on legs I and IV of unknown function. We also analyzed 14 videos of Discocyrtus pectinifemur (Gonyleptidae) mating as a control, a species that lacks these glands. Finally, we looked for chemoreceptors on the legs of female G. perlata using a scanning electron microscope. During copulation, males of both species rubbed the legs of females with their first pair of legs, but not with the regions of these legs where the openings of the glands are. The fourth pair of legs were only used to support the body. Rubbing other body parts of the female by males with their glands was not observed during mating. Setae on the legs of the female did not have tip pores and therefore do not seem to be chemoreceptors. We therefore did not find any evidence that these sexually dimorphic glands in G. perlata release contact pheromones during mating.

Quantitative evidence for spatial variation in the biennial life cycle of the mountain butterfly Erebia euryale (Lepidoptera: Nymphalidae) in the Czech Republic

Irena KLECKOVA, Pavel VRBA, Martin KONVICKA

Eur. J. Entomol. 112 (1): 114-119, 2015 | DOI: 10.14411/eje.2015.003

Erebia euryale (Esper, 1805) is a montane-zone representative of a Holarctic butterfly genus the species of which occur mainly in alpine areas. As in many mountain insects, E. euryale frequently undergoes a prolonged biennial larval development, which can be synchronised across mountains, resulting in prominent biennial peaks in adult emergence. However, the extant reports are often contradictory, suggesting that populations are not synchronized. We present the first quantitative assessment of the situation in the Czech Republic, based on five years of monitoring adults along transects in three major mountain systems in this country. We detected a two order magnitude difference in biennial fluctuations in adult abundance, with peaks in even years (i.e. 2010, 2012) in the Šumava Mts (southwest Czech Republic). There were less distinct odd year (i.e. 2009, 2011, 2013) peaks in the Hrubý Jeseník Mts (northeast) and no fluctuations from year to year in the number of adults recorded in the Krkonoše Mts (north). Although the mechanisms behind these patterns remain unknown, we hypothesize that rugged terrain desynchronises and flat terrain synchronises the length of development of E. euryale. Finally, the different periodicity in the fluctuations in individual mountain ranges is hypothesized to be affected by interactions with larval parasitoids or reflect the different postglacial histories of respective populations.

Immunochemical detection of the crustacean cardioactive peptide in the cephalic ganglia of cockroaches (Blattodea: Blattidae)

Marcin GLADYSZ, Joanna GUZIK, Hana SEHADOVÁ, Bartosz BARAN, Jadwiga BEMBENEK, Bogdan DOLEZYCH

Eur. J. Entomol. 112 (2): 235-244, 2015 | DOI: 10.14411/eje.2015.035

In insects, the crustacean cardioactive peptide (CCAP) is involved mainly in the regulation of ecdysis and is both a hormone secreted into the haemolymph and a neuromodulator or neurotransmitter in the nervous system. However, this peptide has only been recorded in the brains of a few species of insects. The present study examined the distribution of CCAP in the cephalic ganglia of the cockroach, Periplaneta americana, using two kinds of specific antibodies. The antibody directed against synthetic CCAP detected a large number of CCAP-immunoreactive neurons in the protocerebrum, deutocerebrum, tritocerebrum, suboesophageal ganglion, optic lobes, frontal ganglion and neurohemal organs, while the antibody directed against CCAP precursor (pre-propeptide) stained only a few neurons within the central brain and frontal ganglion. The latter antibody also revealed similar sets of neurons in another species of cockroach, Gromphadorhina portentosa, and identified the CCAP precursor of approximately 15 kDa in size in Western blot analyses.

Predation by Macrolophus pygmaeus (Hemiptera: Miridae) on Acyrthosiphon pisum (Hemiptera: Aphididae): Influence of prey age/size and predator's intraspecific interactionsOriginal article

Juliana DURÁN PRIETO, Vincenzo TROTTA, Paolo FANTI, Cristina CASTAÑÉ, Donatella BATTAGLIA

Eur. J. Entomol. 113: 37-43, 2016 | DOI: 10.14411/eje.2016.004

Macrolophus pygmaeus (Hemiptera: Miridae) is an important predator of pests of horticultural crops and here its ability as a predator of Acyrthosiphon pisum (Hemiptera: Aphididae) is addressed for the first time. The percentage predation of the different aphid instars and the number partially consumed were studied. Our results, obtained using choice and no-choice tests, revealed that M. pygmaeus caught and consumed more young than later instars of A. pisum, which confirms results of previous studies using other species of aphids. We also studied the interactions between predators (male/female) foraging in the same patch. When the prey/predator ratio is kept constant at 10 : 1 the average percentage of aphids completely consumed by individual females or males does not change with increase in the number of foraging predators. However, the number of partially consumed aphids decreased when females shared the same patch. In contrast, there was an increase in the number of aphids partially consumed when two males shared the same patch. The results were discussed in terms of potential predator foraging strategies since intraspecific competition is a key factor modulating the dynamics of prey-predator systems.

Responses of grassland arthropods to various biodiversity-friendly management practices: Is there a compromise?

Monika MAZALOVÁ, Jan ©IPO©, Stanislav RADA, Josef KA©ÁK, Boøivoj ©ARAPATKA, Tomá¹ KURAS

Eur. J. Entomol. 112 (4): 734-746, 2015 | DOI: 10.14411/eje.2015.076

The rich species pool in semi-natural grasslands is associated with high spatial and temporal heterogeneity. This empirical study is one of the first to jointly analyze the response of orders, individual species and functional richness of arthropods to particular management practices and to linear landscape features, such as strips of grass and belts of trees. Mostly it was the less mobile, flightless taxa that were negatively affected by immediate disturbance caused by mowing. At a larger time-scale, grasslands managed by mowing once every year, and especially by a combined regime of mowing and grazing, supported the highest species richness of butterflies and beetles. Most functional diversity measures reached maximum values soon after mowing. Both strips of grass and belts of trees substantially affected the invertebrate community structure as the majority of taxa were positively associated with these linear features. Based on our results, we propose postponing mowing to later in the year, mowing in gradual stages, maintaining uncut strips primarily along permanent landscape features and establishing both strips of grass and belts of trees in submontane grassland environments.

Diversity of adipokinetic hormones in termites (Isoptera)Original article

Veronika JEDLIÈKOVÁ, Pavel JEDLIÈKA, Barbora ©PULÁKOVÁ

Eur. J. Entomol. 113: 364-371, 2016 | DOI: 10.14411/eje.2016.047

In this study we report on the structural diversity of adipokinetic hormones (AKHs) in the evolutionarily oldest group of social insects, the termites (Isoptera). Using molecular methods combined with in silico bioinformatic analysis, we studied and compared the sequences coding for these neuropeptides in thirteen species of five families of Isoptera. There are three types of AKH octapeptides in termites: Empusa pennata adipokinetic hormone (Emppe-AKH; pQVNFTPNWamide), Microhodotermes viator corpus cardiacum peptide (Micvi-CC; pQINFTPNWamide) and Periplaneta americana cardioaccelerating hormone (Peram-CAH-I; pQVNFSPNWamide). Of these the Peram-CAH-I was the most frequently bioactive form detected in representatives of four out of the six families studied. The complete AKH preprohormones in the termites studied shared at least an 84% amino acid similarity. In agreement with current phylogenetic scenarios of termites as an internal monophyletic clade nested within cockroaches (Blattaria) in the proximity of the family Blattidae, our phylogenetic analysis of the AKH precursor sequences (in the absence of data for the Cryptocercidae) placed the Blattidae (Periplaneta americana) as a sister group of termites and the AKHs of other cockroach families (Blattellidae and Blaberidae) were more divergent from those of termites. Representatives of the basal termite families Mastotermitidae and Archotermopsidae (but also one rhinotermitid genus Prorhinotermes) occurred separately from the phylogenetically advanced lineage (Rhinotermitidae and Termitidae), and Neotermes (Kalotermitidae) was sister to all other termites included.

Characterization of the complete mitochondrial genome of the Oriental armyworm, Mythimna separata (Lepidoptera: Noctuidae)

Qiu-Ning LIU, Dan-Dan Bian, Sen-Hao JIANG, Bao-Ming GE, Chun-Lin ZHOU, Bo-Ping TANG

Eur. J. Entomol. 112 (3): 399-408, 2015 | DOI: 10.14411/eje.2015.055

The complete mitochondrial genome (mitogenome) of Mythimna separata (Lepidoptera: Noctuidae) was determined to be 15,329 bp, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and an A+T-rich region. The AT skew of this mitogenome was slightly negative and the nucleotide composition was also biased toward A+T nucleotides (81.00%). All PCGs were initiated by ATN codons, except for cytochrome c oxidase subunit 1 (cox1) gene, which was initiated by CGA. Five of the 13 PCGs have the incomplete termination codon, T or TA. All the tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The A+T-rich region of the mitogenome was 372 bp in length and consisted of several features common to the Noctuidae. Phylogenetic analysis confirmed the placement of M. separata within the Noctuidae.

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