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Harmonia axyridis (Coleoptera: Coccinellidae): Smelling the rat in native ladybird declinesPoint of viewJohn J. SLOGGETTEur. J. Entomol. 114: 455-461, 2017 | DOI: 10.14411/eje.2017.058 In the last two decades a huge amount of research has focused on the invasive harlequin ladybird, Harmonia axyridis, particularly on potential or actual deleterious effects that have arisen after it has colonised new regions. A focus of this work has been real or anticipated declines in native ladybird abundance since the introduction of H. axyridis, for which it is deemed responsible. Scientists have generally painted a very bleak picture of the effects of H. axyridis on native species: in this paper I argue that the picture painted is often too bleak. I use the case of the 2-spot ladybird, Adalia bipunctata, the species most often invoked as threatened by H. axyridis, to illustrate my point. While there is little question that H. axyridis has led to a decline in A. bipunctata populations in Europe, it seems likely that prior to the invasive ladybird's arrival A. bipunctata occurred in artificially high numbers in the urban environments in which it was typically studied. Pollution in towns and cities led to enhanced numbers of prey aphids on plants there which initially favoured A. bipunctata, and later H. axyridis. Thus one species, A. bipunctata, that has benefitted from an association with humans has been replaced by another, H. axyridis, just as brown rats replaced black rats in Europe and North America. Viewed with a longer perspective, A. bipunctata has more likely declined back to pre-industrial levels: the artificially high level from which it has declined recently was not a 'natural' one, and thus its decline from this level does not imply that it is now threatened or endangered. More broadly, we need a wider perspective, encompassing other ladybirds, longer timeframes and better comparisons with other (non-ladybird) invasive species to more clearly assess whether H. axyridis really poses as much of a threat as is often proposed. |
Efficiency of two methods of sampling used to assess the abundance and species diversity of adult Syrphidae (Diptera) in mountainous meadows in the Austrian and Swiss AlpsOriginal articleRaja I. HUSSAIN, Ronnie WALCHER, David BRANDL, Arne ARNBERGER, Johann G. ZALLER, Thomas FRANKEur. J. Entomol. 115: 150-156, 2018 | DOI: 10.14411/eje.2018.014 The outcome of assessments of the biodiversity of a taxonomic group often depend on the sampling method. The choice of an adequate method is especially important for biomonitoring purposes. In this study, the effectiveness of two methods of sampling syrphids (Diptera: Syrphidae) is compared: observation plot method vs. line transect, both sampled by sweep netting. Altogether, 18 meadows were selected in three mountain regions in the Austrian and Swiss Alps. We recorded a significantly higher abundance and richness of syrphids using the observation plot method than the line transect method in 2015. Comparing data for one region recorded in 2015 and 2016, similar results were obtained. Syrphid species assemblages were affected by sampling method in both years. More syrphid species and individuals were recorded using the observation plot method, which makes it more suitable for studies aiming at comparing differences in the numbers of adult syrphids in different grassland habitats. |
Overwintering of ladybirds (Coleoptera: Coccinellidae) on Scots pine in Central EuropeOriginal articleMilada HOLECOVÁ, Peter ZACH, Katarína HOLLÁ, Miroslava ©EBESTOVÁ, Mária KLESNIAKOVÁ, Anna ©ESTÁKOVÁ, Alois HONÌK, Oldøich NEDVÌD, Michal PARÁK, Zdenka MARTINKOVÁ, Juraj HOLEC, Sandra VIGLÁ©OVÁ, Peter M.J. BROWN, Helen E. ROY, Ján KULFANEur. J. Entomol. 115: 658-667, 2018 | DOI: 10.14411/eje.2018.065 We surveyed ladybirds (Coleoptera: Coccinellidae) in 10 stands of Scots pine (Pinus sylvestris), all monoculture stands 5-100 years old, in western Slovakia, Central Europe, over two successive periods, October 2013 - March 2014 and October 2014 - March 2015. The winter in each period was exceptionally mild. Ladybirds were collected from the lower branches of pine trees using beating trays and were present in 61% of the 1040 samples (one sample containing ladybirds from 20 branches, 1 m long each). In total 3965 individuals of 20 species were recorded. Non-conifer dwelling species associated with broadleaved trees or herbaceous plants prevailed (45% of species), followed by conifer specialists (40%) and generalists (15%). Although 13 species were found at least in one winter month, December, January or February, only four of them, Exochomus quadripustulatus, Coccinella septempunctata, Harmonia axyridis and Hippodamia variegata, were recorded continually during both winters. The number of species, the abundance of all ladybirds and the abundance of dominant species (E. quadripustulatus, C. septempunctata and H. axyridis) decreased from late autumn towards winter and remained lowest during this most adverse time of the year for ladybirds. Overwintering species assemblages of ladybirds changed over time and varied with age of pine stand. Our results suggest that Scots pine in Central Europe supports species rich assemblages of ladybirds from late autumn to early spring and, being widely distributed, it could be suited to winter surveying of ladybirds at large spatial scales to reveal behavioural and ecological responses of species to changing weather or different climates. |
Implications of insect responses to supernormal visual releasing stimuli in intersexual communication and flower-visiting behaviour: A reviewReviewKarl KRALEur. J. Entomol. 113: 429-437, 2016 | DOI: 10.14411/eje.2016.056 Animals, including human beings, tend to respond more strongly to stimuli that are associated with the highest relative rewards. This applies not only to food rewards but also to reproductive success. In the present review article this issue is discussed for insects in connection with intersexual communication and flower-visiting behaviour. Implications of the preference for supernormal visual releasing stimuli are examined from a sensory and evolutionary perspective, including a consideration of the choice of potential mates and recognition of the most rewarding flowers. |
The diversity of feeding habits recorded for water boatmen (Heteroptera: Corixoidea) world-wide with implications for evaluating information on the diet of aquatic insectsReviewChristian W. HÄDICKE, Dávid RÉDEI, Petr KMENTEur. J. Entomol. 114: 147-159, 2017 | DOI: 10.14411/eje.2017.020 Food webs are of crucial importance for understanding any ecosystem. The accuracy of food web and ecosystem models rests on the reliability of the information on the feeding habits of the species involved. Water boatmen (Corixoidea) is the most diverse superfamily of water bugs (Heteroptera: Nepomorpha), frequently the most abundant group of insects in a variety of freshwater habitats worldwide. In spite of their high biomass, the importance of water boatmen in aquatic ecosystems is frequently underestimated. The diet and feeding habits of Corixoidea are unclear as published data are frequently contradictory. We summarise information on the feeding habits of this taxon, which exemplify the difficulties in evaluating published data on feeding habits in an invertebrate taxon. It is concluded that Corixoidea are, unlike other true bugs, capable of digesting solid food, but their feeding habits are still insufficiently known. The dominant feeding strategy in this taxon is zoophagy, but several species consume other foods, particularly algae and detritus. Only members of the subfamily Cymatiainae seem to be exclusively predators. In other subfamilies, the diet of different species and different sexes or populations of a single species may vary depending on the food available or is still unknown. We conclude, that a multi-method approach is needed to elucidate the feeding habits of aquatic insects and invertebrates in general. |
Inheritance of diapause regulation in the multicoloured Asian ladybird Harmonia axyridis (Coleoptera: Coccinellidae)Original articleSergey Ya. REZNIK, Antonina A. OVCHINNIKOVA, Andrey N. OVCHINNIKOV, Larisa V. BARABANOVA, Natalia A. BELYAKOVAEur. J. Entomol. 114: 416-421, 2017 | DOI: 10.14411/eje.2017.053 It is known that females from native populations of the multicoloured Asian ladybird, Harmonia axyridis, have a strong photoperiodic response (enter reproductive diapause under short photoperiods), whereas the proportion of diapausing females from invasive populations is less dependent on day length. The aim of the present study was to determine the mode of inheritance of these differences. The experiments were conducted with two laboratory populations of H. axyridis, the High Diapause (HD) population originated from Irkutsk (Southern Siberia, ca 52.3°N, 104.3°E) and the Low Diapause (LD) population originated from Sochi (North Caucasus, ca 43.6°N, 39.6°E). Reciprocal first generation hybrids and reciprocal backcrosses were investigated. Under a strong diapause-inducing photoperiod (12 h) 100% of the females from the HD population and about 70% of those from the LD population entered diapause. First generation hybrids, as well as their backcrosses with individuals from the HD population, showed almost 100% diapause. Among the backcrosses with the LD population the percentage of diapausing females was widely variable (70-100%) but close to the average between the two populations. The comparison of reciprocal crosses did not reveal any significant difference. We conclude that photoperiodic induction of diapause in the populations of H. axyridis studied is most probably determined by several genes (although one of them evidently plays a leading role with diapause being dominant over non-diapause) and that male and female genotypes are equally important in the determination of female reproductive diapause. |
Revision, phylogeny and phylogeography of the cicada genus Auritibicen (Hemiptera: Cicadidae), with descriptions of ten new speciesOriginal articleXu WANG, Masami HAYASHI, Cong WEIEur. J. Entomol. 115: 53-103, 2018 | DOI: 10.14411/eje.2018.007 We review the cicada genus Auritibicen Lee, 2015 based on the description of ten new species: A. aethus sp. n., A. daoxianensis sp. n., A. pallidus sp. n., A. rotundus sp. n., A. curvatus sp. n., A. purus sp. n., A. parvus sp. n., A. gracilis sp. n., A. septatus sp. n. and A. lijiangensis sp. n. Auritibicen shikokuanus (Kato, 1959) is confirmed to be a synonym of Auritibicen kyushyuensis (Kato, 1926). Diagnoses and descriptions, along with illustrations of the structure of male genitalia, are provided for all Auritibicen species. The systematics of Auritibicen is elucidated using both morphological and molecular characterization. Thirty-five morphological characters of the 24 species of Auritibicen and one outgroup taxon, Chremistica ochracea (Walker, 1850), were scored. Morphological phylogenetic analyses reveal the relationships among related species of Auritibicen, which are supported by a number of morphological characters. The mitochondrial gene fragments of Cytochrome Oxidase I (COI) of 11 species of Auritibicen and two outgroup Lyristes species were analyzed and yielded identical robust phylogenetic trees. The phylogram based on a Bayesian analysis of both morphological and molecular data is similar to the ML/BI topologies based only on the molecular data. The molecular phylogenetic analysis indicates that species of Auritibicen are structured phylogeographically, with related species clustered into three lineages. The divergence time estimated based on molecular data indicates that the divergence of Auritibicen from Lyristes occurred during the Miocene, and the most recent common ancestor (tMRCA) of Auritibicen evolved during the Pliocene. However, the time when the main divergence events of species of Auritibicen occurred was the Pleistocene. From the combination of the phylogeny and updated geographical distributions, we infer that the center of distribution of Auritibicen could be Southwest China (e.g., Sichuan and Yunnan Provinces), from where species of this genus spreaded northeastwards to Shaanxi, Hubei and other provinces along the Qinling and Daba Mountains, then further northeastwards to Hebei Province in China and also to Far East Russia, the Korean Penisula, and Japan. |
Isolation and characterization of 15 microsatellite markers for the highly invasive box tree moth Cydalima perspectalis (Lepidoptera: Crambidae)NoteAudrey BRAS, Laure SAUNÉ, Alain ROQUES, Jérôme ROUSSELET, Marie-Anne AUGER-ROZENBERGEur. J. Entomol. 115: 264-267, 2018 | DOI: 10.14411/eje.2018.026 In this study, we report the development of a set of 15 polymorphic microsatellite markers for the box tree moth, Cydalima perspectalis (Walker), a highly invasive insect in Europe causing significant damage to natural and ornamental Buxus trees. The markers were characterized for four distant populations in both its native (China, two populations) and invasive ranges (Czech Republic and Turkey, one population each). The number of alleles ranged from 2 to 12. No marker significantly deviated from the Hardy-Weinberg equilibrium for all the populations sampled. These microsatellite markers are promising tools for further studies on the invasive pathways and dispersal pattern of the box tree moth in Europe. |
Does Hartigiola annulipes (Diptera: Cecidomyiidae) distribute its galls randomly?Original articleSebastian PILICHOWSKI, Marian J. GIERTYCHEur. J. Entomol. 115: 504-511, 2018 | DOI: 10.14411/eje.2018.050 It is expected that environmental conditions impact the distribution of galls on host plants. Moreover, insects may induce their galls randomly or choose certain parts of a host to induce such growths. This study aimed to determine whether or not the gall midge, Hartigiola annulipes (Diptera: Cecidomyiidae), which induces galls on leaves of the European beech (Fagus sylvatica), prefers leaves facing a particular cardinal direction. In addition, we wanted to ascertain whether the galls are evenly spread across three leaf zones: proximal, median and distal, distinguished by dividing leaf area along the midrib. The results show that H. annulipes chose leaves facing various directions in different studied locations, and leaf choice is not restricted to the specific leaf area, a parameter that accurately reflects the light conditions of leaf growth. Moreover, the medial leaf zone was preferred, while the distal zone was avoided. The choice of the leaf zone modified the distance between the mid-rib and a gall. Gall distribution in the crown of trees is probably random, while at the leaf level, it is determined by leaf morphology. |
A "clean" alien species? Parasites of the invasive ladybird Harmonia axyridis (Coleoptera: Coccinellidae)Original articleKrzysztof DUDEK, Pawe³ SIENKIEWICZ, Dariusz J. GWIAZDOWICZ, Piotr TRYJANOWSKIEur. J. Entomol. 114: 350-354, 2017 | DOI: 10.14411/eje.2017.044 The multicoloured Asian ladybird Harmonia axyridis is an invasive insect that can negatively influence biodiversity and human economy in invaded areas. According to the enemy release hypothesis, invasive alien species are often little affected by parasites and other enemies. We studied the prevalence of common parasites of insects infesting and infecting H. axyridis in NW Poland. A large sample of 2351 individuals was collected and divided into two groups: 1180 beetles were dissected and examined for the presence of eugregarines, nematodes and Laboulbeniales fungi, and 751 were checked for phoretic mites. Our results show that H. axyridis is indeed parasitized infrequently. The prevalence of eugregarines and nematodes was very low (1.5% and 0.4%, respectively). No specimens of Laboulbeniales or phoretic mites were found. Our study indicates that in NW Poland H. axyridis is rarely infested or infected by parasites. This paper reports for the first time the infection of H. axyridis by the eugregarine Gregarina barbarara. |
Warp-speed adaptation to novel hosts after 300 generations of enforced dietary specialisation in the seed beetle Callosobruchus maculatus (Coleoptera: Chrysomelidae: Bruchinae)Original articleThomas N. PRICE, Aoife LEONARD, Lesley T. LANCASTEREur. J. Entomol. 114: 257-266, 2017 | DOI: 10.14411/eje.2017.031 Herbivorous insects are often highly specialised, likely due to trade-offs in fitness on alternative host species. However, some pest insects are extremely adaptable and readily adopt novel hosts, sometimes causing rapid expansion of their host range as they spread from their original host and geographic origin. The genetic basis of this phenomenon is poorly understood, limiting our ability to predict or mitigate global insect pest outbreaks. We investigated the trajectory of early adaptation to novel hosts in a regionally-specialised global crop pest species (the cowpea seed beetle Callosobruchus maculatus). After experimentally-enforced dietary specialisation for nearly 300 generations, we measured changes in fitness over the first 5 generations of adaptation to 6 novel hosts. Of these, C. maculatus reproduced successfully on all but one, with reduced fitness observed on three hosts in the first generation. Loss of fitness was followed by very rapid, decelerating increases in fitness over the first 1-5 generations, resulting in comparable levels of population fitness to that observed on the original host after 5 generations. Heritability of fitness on novel hosts was high. Adaptation occurred primarily via changes in behavioural and phenological traits, and never via changes in offspring survival to adulthood, despite high heritability for this trait. These results suggest that C. maculatus possesses ample additive genetic variation for very rapid host shifts, despite a prolonged period of enforced specialization, and also suggest that some previously-inferred environmental maternal effects on host use may in part actually represent (rapidly) evolved changes. We highlight the need to examine in more detail the genetic architecture facilitating retention of high additive genetic variation for host shifts in extremely adaptable global crop pests. |
Dinocampus coccinellae (Hymenoptera: Braconidae) utilizes both Coccinellini and Chilocorini (Coleoptera: Coccinellidae: Coccinellinae) as hosts in Kashmir HimalayasOriginal articleAmir MAQBOOL, Imtiaz AHMED, Piotr KIE£TYK, Piotr CERYNGIEREur. J. Entomol. 115: 332-338, 2018 | DOI: 10.14411/eje.2018.033 Dinocampus coccinellae is a parasitoid wasp usually parasitizing ladybird beetles of the tribe Coccinellini. A field survey conducted between March and November 2016 revealed three hosts of this parasitoid in the Srinagar district of the Indian state of Jammu and Kashmir: two members of the Coccinellini (Oenopia conglobata and Coccinella undecimpunctata) and one of the Chilocorini (Priscibrumus uropygialis). Proportion of the latter (atypical) host that were parasitized was 0.09 and intermediate between that recorded for C. undecimpunctata (0.06) and O. conglobata (0.14). A series of laboratory experiments revealed that while a member of Coccinellini (O. conglobata) was more often attacked by D. coccinellae than a member of Chilocorini (P. uropygialis), the proportions of each species from which parasitoids emerged did not differ significantly. There were no significant differences between D. coccinellae females bred from O. conglobata and P. uropygialis, with respect to selection of the two host species and their suitability for the development of the parasitoid. However, members of the Chilocorini other than P. uropygialis (Chilocorus infernalis and Simmondsius pakistanensis) were rarely attacked by D. coccinellae and parasitoid larvae did not emerge from any of those attacked. The results of our experiments indicate that in Kashmir Himalayas D. coccinellae is adapted to parasitize hosts belonging to both Coccinellini and Chilocorini. |
The life cycles of Boyeria irene and Onychogomphus uncatus (Odonata: Aeshnidae, Gomphidae) in western Spain: A biometric studyOriginal articleTatiana VELASCO-VILLANUEVA, Francisco CAMPOS, Ulf NORLING, Manuel FERRERAS-ROMEROEur. J. Entomol. 115: 684-696, 2018 | DOI: 10.14411/eje.2018.067 Co-occurrence of species with similar trophic requirements, such as odonates, seems to depend both on them occupying different microhabitats and differing in their life-cycles. The life cycles of the dragonflies Boyeria irene and Onychogomphus uncatus were studied in two consecutive years, mainly by systematic sampling of larvae in seven permanent head courses that constitute the upper basin of the River Águeda, western Spain, in the central part of the ranges of these two species. The size ranges of the last five larval stadia of both species were established based on biometric data. The eggs of the egg-overwintering aeshnid hatched in late spring and early summer and for the gomphid hatching peaked in middle-late summer. Both species showed mixed voltinism with "cohort splitting". B. irene had a dominant three-year development (partivoltinism), with some developing in two years (semivoltinism). O. uncatus requires four, sometimes three years to complete development (all partivoltine). B. irene larvae spent the winter before emergence in the last three, maybe four stadia, as a "summer species". O. uncatus mainly behaved as a "spring species", most larvae spending the last winter in the final larval stadium. |
A new look at the nature of insect juvenile hormone with particular reference to studies carried out in the Czech RepublicKarel SLÁMAEur. J. Entomol. 112 (4): 567-590, 2015 | DOI: 10.14411/eje.2015.073 This article is a comprehensive summary of the 50-year history of physiological investigations in the Czech Republic into the mode of action of the corpus allatum hormone (CAH) in insects, which is commonly known as the juvenile hormone (JH). During this period 4000 synthetic JH- mimetic bioanalogues were tested. The sesquiterpenoid epoxy-homofarnesoate (JH-I), which is generally thought to be the true JH of insects, is an excretory product of the male colleterial gland, not an insect hormone. There are two principal hormones produced by the insect neuroendocrine system: activation hormone (AH) produced by neurosecretory cells in the brain and JH secreted by the corpora allata. The prothoracic glands are a subordinated target of JH, not PTTH; they are not involved in the regulation of moulting in insects. The development of larval, pupal and adult structures depends primarily on inherited instructions encoded within the genome, not on high, medium or low concentrations of JH. At the level of epidermal cells, the responses to JH are always "all-or-none" with intermediate forms mosaic mixtures of cells of previous and future developmental stages. |
Fine structure of the external sheaths of the ovipositor of Aphidius ervi (Hymenoptera: Braconidae)Original articleSara RUSCHIONI, Paola RIOLO, Roberto ROMANI, Donatella BATTAGLIA, Nunzio ISIDOROEur. J. Entomol. 115: 296-302, 2018 | DOI: 10.14411/eje.2018.028 The function and structure of the ovipositor in Hymenoptera have been studied intensively, although there is a lack of information on the external sheaths. We provide here a contribution on the structure of the external sheaths of the ovipositor of the parasitic wasp Aphidius ervi, in particular the secretory structure is described for the first time. These glands are made up of a large epithelial structure that consists a single layer of large secretory cells that occupy most of the lumen of the valve and belong to gland cell class 1. Based on the different features of the glands, a lubricating and/or host marking function is hypothesized and discussed. |
Effect of pine reforestation associated with soil disturbance on ant assemblages (Hymenoptera: Formicidae) in a semiarid steppeOriginal articleChema CATARINEU, Joaquín REYES-LÓPEZ, Joan A. HERRAIZ, Gonzalo G. BARBERÁEur. J. Entomol. 115: 562-574, 2018 | DOI: 10.14411/eje.2018.054 Soil and changes in vegetation may affect ant assemblages, but the relative importance of each in different habitats is not well characterized. In particular, information on the effects of ecological restoration on arthropods is scarce. It was decided, therefore, to study how reforestation may affect an ant assemblage. Ants were sampled in area that had been reforested and adjacent grassland using pitfall traps. Soil surface and vegetation were characterized. The disturbance of the vegetation caused by reforestation resulted in a decrease in the cover of Stipa tenacissima and Cistaceae and an increase in the cover of pine. The mechanical preparation of the site also resulted in changes in the soil surface, with an increase in the cover of stones and rocks. Ant species richness and abundance were greater at the reforested site than in the grassland and more species showed a positive than a negative response to reforestation. The underlying causes of this pattern are mainly related to changes in vegetation and structure of the soil surface and are associated with the increase in the cover of pine, which most probably provided additional food resources, and the greater cover of stones and rocks that provided more shelter for the ant assemblage. |
An overview of irritans-mariner transposons in two Mayetiola species (Diptera: Cecidomyiidae)Original articleWiem BEN AMARA, Salma DJEBBI, Dhia BOUKTILA, Mohamed MAKNI, Hanem MAKNI, Maha MEZGHANI-KHEMAKHEMEur. J. Entomol. 114: 379-390, 2017 | DOI: 10.14411/eje.2017.049 Mariner-like elements (MLEs) are widespread Class II transposable elements in insects that are subdivided into several subfamilies. In the current study, we carried out in silico analysis and in vitro experiments to identify MLEs belonging to the irritans subfamily in two cecidomyiid flies, Mayetiola destructor and M. hordei. In silico investigation of M. destructor genome allowed the identification of 25 irritans-like elements, which were mostly defective due to several mutations. These defective forms might be the remnants of active elements that ancestrally invaded the host genome. Structural analyses, including signature motifs and transposase-encoding ORFs, revealed structural heterogeneity and the presence of two full length copies. Five consensuses, reflecting the probable evolutionary groups of these elements, were constructed, based on a similarity matrix. The first consensus (Maymarcons1) belonged to Himar1-like elements reported in other insects, while the remaining four (Maymarcons2 to 5) seemed to be more specific to Cecidomyiidae. Moreover, the presence of elements belonging to the Maymarcons4 group was ascertained by PCR amplification, in both Mayetiola species, and was further identified in the Transcriptome Shotgun Assembly (TSA) of the orange fly, Sitodiplosis mosellana (Cecidomyiidae), suggesting the existence of irritans elements within the Cecidomyiidae, which were derived from an ancestral species by vertical transmission during speciation. On the other hand, consensuses that are specific to M. destructor could be derived from a more recent invasion. This study suggests that both M. destructor and M. hordei genomes have been invaded by irritans elements many times with at least two different evolutionary histories. |
The pheromone verbenone and its function in Dendroctonus armandi (Coleoptera: Curculionidae: Scolytinae)Original articleMingzhen ZHAO, Lulu DAI, Yaya SUN, Danyang FU, Hui CHENEur. J. Entomol. 114: 53-60, 2017 | DOI: 10.14411/eje.2017.008 The Chinese white pine beetle, Dendroctonus armandi Tsai and Li is a native species of bark beetle and one of the most destructive in much of western China. Little is known about the characterization of the pheromones trans-verbenol and verbenone, and their functions in D. armandi are unknown. Electroantennogram tests (EAG) and olfactory assays (Y-tube assays) in the laboratory revealed that (1) trans-verbenol may be an anti-aggregation pheromone for male and an aggregation pheromone for female D. armandi and (2) female beetles are more attracted to controls (hexane) than low concentrations of verbenone and male beetles more attracted to controls than high concentrations of verbenone. Field trials indicated that the addition of verbenone to bait used to trap D. armandi remarkably decreased the efficiency of field trapping. These results indicate that verbenone is an anti-aggregation pheromone for male D. armandi. This research provides evidence of the role of verbenone among the different types of pheromones. The pheromone verbenone clearly could be used to protect healthy Chinese white pines. |
Assessing genetic and morphological variation in populations of Eastern European Lucilia sericata (Diptera: Calliphoridae)Original articleAnna V. DIAKOVA, Dmitry M. SCHEPETOV, Nadezhda Y. OYUN, Anatole I. SHATALKIN, Tatiana V. GALINSKAYAEur. 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. |
Variation in the morphology of the wings of the endangered grass-feeding butterfly Coenonympha oedippus (Lepidoptera: Nymphalidae) in response to contrasting habitatsOriginal articleJure JUGOVIC, Sara ZUPAN, Elena BU®AN, Tatjana ÈELIKEur. J. Entomol. 115: 339-353, 2018 | DOI: 10.14411/eje.2018.034 At the southern limit of its range the endangered butterfly Coenonympha oedippus inhabits grasslands (wet, dry) that differ significantly in the abundance of its larval hostplants (wet > dry) and mean annual air temperature (wet < dry). We determined the difference in the wing morphology of individuals in the two contrasting habitats to test whether and how traits associated with wing size, shape and eye like spots vary in the sexes and two ecotypes. We show that sexual dimorphism follows the same (wing size and shape, number of eyespots on forewing) or different (relative area of eyespots on hindwings) patterns in the two contrasting habitats. Irrespective of ecotype, females had larger, longer and narrower wings, and more forewing eyespots than males. Sexual dimorphism in the relative area of eyespots on hindwing was female-biased in the wet, but male-biased in the dry ecotype. Ecotype dimorphism in wing size and the relative area of eyespots on the hindwing is best explained by mean annual air temperature and abundance of host-plants. While ecotype dimorphism in wing size did not differ between sexes, neither in direction (wet > dry) or in degree, in the two sexes the relative area of eyespots on hindwing had opposite patterns (males: dry > wet; females: wet > dry) and was more pronounced in males than in females. The differences in wing shape between ecotypes were detected only in the hindwings of males, with more rounded apex in the dry than in the wet ecotype. We discuss the life-history traits, behavioural strategies and selection mechanisms, which largely account for the sex- and ecotype-specific variation in wing morphology. |
Regulation of larval diapause by colony-founding queens of Crematogaster teranishii (Hymenoptera: Formicidae)Original articleKeiji NAKAMURAEur. J. Entomol. 115: 697-702, 2018 | DOI: 10.14411/eje.2018.068 Nuptial flights of Crematogaster teranishii Santschi occur in autumn. Queens and possibly larvae pass the first winter without workers in Okayama, Japan. This study examines and tests the hypothesis that C. teranishii queens regulate not only their own diapause, but also that of their larvae. Some queens collected immediately after their nuptial flight in early October were exposed to a low temperature of 10°C for 3 months before transfer to 25°C; these queens started oviposition approximately 8 days after the transfer. Larvae reared by these previously chilled queens pupated synchronously until day 50. Other field-collected queens reared at 25°C without prior chilling reproduced soon after collection. They started oviposition, but the development of their larvae was arrested and pupation occurred late or not at all within the120 day experimental period. The delay in pupation in colonies in which the queens were not previously exposed to low temperature strongly indicates that many larvae are in diapause. Because eggs and larvae were not exposed to low temperatures, they were unable to determine the developmental pathway providing the best response to environmental factors. Results indicate that queens regulate whether their larvae undergo diapause. |
Influence of prolonged dietary experience during the larval stage on novel odour preferences in adults of noctuid stem borer moths (Lepidoptera: Noctuidae)Original articleChristophe PETIT, Peter AHUYA, Bruno LE RU, Laure KAISER-ARNAULD, Myriam HARRY, Paul-André CALATAYUDEur. J. Entomol. 115: 112-116, 2018 | DOI: 10.14411/eje.2018.009 In Lepidoptera, larval dietary experience of volatile cues can induce adult preference for these cues. However, such induction may require several generations, depending in part on the degree of specialization of the insects. In a previous study, using species of noctuid stem borers with different diet breadths, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and monophagous Busseola nairobica, it was shown that in S. nonagrioides, one generation was enough to induce a preference for vanillin in the resulting gravid females, whereas even two generations failed to induce a response in adults of Busseola spp. In this study, we checked whether a higher number of generations of exposure to a vanillin-enriched medium could induce a significant olfactory preference for this medium in the species B. fusca and B. nairobica, which have narrower host-plant utilization ranges than S. nonagrioides. Larvae were reared to the adult stage on an artificial diet enriched with vanillin for periods of from 2 to 7 or 8 generations, followed by two-choice tests on gravid females using a Y-tube olfactometer. The results showed different responses according to the species: for the oligophagous B. fusca, there was no significant effect of the conditioning, while a significant preference for the odours emitted by this new vanillin-enriched diet was recorded for the polyphagous S. nonagrioides and monophagous B. nairobica, but after different numbers of generations. In conclusion, different diet breadths seem to be associated with different levels of plasticity in the odour preference of adults. The implication of this result for insects' adaptability in a changing landscape is discussed. |
Effect of ant attendance on aphid population growth and above ground biomass of the aphid's host plantOriginal articleAfsane HOSSEINI, Mojtaba HOSSEINI, Noboru KATAYAMA, Mohsen MEHRPARVAREur. J. Entomol. 114: 106-112, 2017 | DOI: 10.14411/eje.2017.015 Ant-aphid mutualism is considered to be a beneficial association for the individuals concerned. The population and fitness of aphids affected by ant attendance and the outcome of this relationship affects the host plant of the aphid. The main hypothesis of the current study is that ant tending decreases aphid developmental time and/or increases reproduction per capita, which seriously reduces host plant fitness. The effect of attendance by the ant Tapinoma erraticum (Latreille, 1798) (Hymenoptera: Formicidae) on population growth and duration of different developmental stages of Aphis gossypii Glover (Hemiptera: Aphididae) were determined along with the consequences for the fitness of the host plant of the aphid, Vicia faba L., in greenhouse conditions. The initial aphid density was manipulated in order to study aphid performance due to density-dependent changes in ant attendance. The population growth rate of ant attended aphids was more than that of unattended aphids. However, the ratio of 1st-2nd nymphs to adults in aphid populations attended by ants was lower. The yields of bean plants on which the aphids were attended by ants were significantly greater than those of unattended plants. This study indicates that ants not only increase aphid fitness in terms of their population growth rate, but also benefit the host plant. |
Motorway as a barrier to dispersal of the threatened dragonfly Sympetrum depressiusculum (Odonata: Libellulidae): Consequence of mortality or crossing avoidance?Original articleHana ©IGUTOVÁ, Filip HARABI©, Michal HYKEL, Ale¹ DOLNÝEur. J. Entomol. 114: 391-399, 2017 | DOI: 10.14411/eje.2017.050 Infrastructure is one of the main causes of landscape fragmentation, which results in isolation and loss of populations. Although the negative effect of roads on insects is well documented, only a minority of studies has focused on roads in the context of barriers to dispersal. Flying species in particular have been neglected. We investigated the effect of a four-lane motorway as a barrier to the movement of an isolated population of the threatened dragonfly Sympetrum depressiusculum in an agricultural landscape in Central Europe. Generalized additive models were used to assess the motorway's effect on (i) the distribution of adult dragonflies in patches of terrestrial habitat surrounding their natal site, and (ii) individual flight behaviour (i.e. willingness or unwillingness to cross the motorway). Movement patterns of marked adults throughout the landscape were also investigated. During one season, significantly fewer adults were found at patches located on the far side of the motorway, indicating it has a barrier effect. Observations on flight behaviour revealed no apparent effect of the motorway. The possible barrier effect for the species studied was therefore presumed to be a consequence of road mortality. Our results indicate that the motorway may influence the dispersal of this threatened species of dragonfly, which is a habitat specialist with particular requirements for its terrestrial environment. Negative effects on other species with similar behaviour and strategy can be presumed. When establishing new habitats, carrying out reintroductions or translocations, it is necessary to consider that roadways may reduce population size and affect population dynamics by limiting dispersal. |
Puncture vs. reflex bleeding: Haemolymph composition reveals significant differences among ladybird species (Coleoptera: Coccinellidae), but not between sampling methodsOriginal articleMichal KNAPP, Pavel DOBE©, Michal ØEØICHA, Pavel HYR©LEur. J. Entomol. 115: 1-6, 2018 | DOI: 10.14411/eje.2018.001 Reflex bleeding is one of the many anti-predation behavioural tactics used by insects. This behaviour is recorded widely in several insect taxa and provides scientists with an interesting opportunity for easily obtaining samples of haemolymph for physiological experiments. However, there is no good evidence that haemolymph and reflex blood have the same characteristics. In this study, we compared three basic characteristics of reflex blood and haemolymph collected from the body cavity, of three species of ladybirds: Harmonia axyridis, Coccinella septempunctata and Ceratomegilla undecimnotata. In the reflex blood we recorded the same concentration of haemocytes and total protein, and level of antimicrobial activity against Escherichia coli as in samples of haemolymph collected from within the body cavity. Therefore, reflex blood is a promising source of haemolymph for use in many physiological and immunological studies. It is the best way of collecting haemolymph if one wants to avoid challenging the immune system and concurrently also enables one to repeatedly collect haemolymph from one individual without injuring it, which would initiate repair mechanisms. The interspecific comparison indicates significant differences among the species studied in three characteristics measured. Interestingly, the native species Ceratomegilla undecimnotata has nearly as effective immune system as the invasive Harmonia axyridis based on the level of antibacterial activity against Escherichia coli. |
Population dynamics of Coccinella septempunctata (Coleoptera: Coccinellidae) in the region of Edremit Gulf in West Anatolia (Mount Ida)NoteAli ÖZPINAR, Ali Kürºat ªAHİN, Burak POLATEur. J. Entomol. 115: 418-423, 2018 | DOI: 10.14411/eje.2018.041 This study reports seasonal presence of Coccinella septempunctata L. (Coleoptera: Coccinellidae) in Southeast Turkey, in 2008, 2009 and 2010. Samples were collected from crops in agricultural areas at altitudes of 10 m, 800 m and 1400 m from stands of wild herbaceous plants , and at 1750 m from stone debris fields. First C. septempunctata adults were collected at the beginning of June at Tentcamp (800 m) and Tozlu (1400 m), early in July at Sarikiz (1700 m) when the mean air temperature reached 30°C. Adults became active in spring, after aestivating around Sarikiz and overwintering there under snow. First adults emerged on 2nd April in 2009 around Edremit Gulf when mean air temperature reached 14.8°C. Adult and immature stages of C. septempunctata were recorded attacking aphid populations till the end of June. C. septempunctata was present there for only one period each year during which they completed one generation. Adult individuals of this generation returned to Mount Ida to aestivate. Maximum numbers of adults present on Mount Ida in the first week of August in 2009 and 2010 were recorded. C. septempunctata adults aestivate and overwinter at Sarikiz on Mount Ida after completing their development on aphids in April, May and June around Edremit Gulf. |
Effect of aphid abundance and urbanization on the abundance of Harmonia axyridis (Coleoptera: Coccinellidae)Original articleAlois HONÌK, Zdenka MARTINKOVÁ, Jan ©TROBACHEur. J. Entomol. 115: 703-707, 2018 | DOI: 10.14411/eje.2018.069 The factors that affect the local distribution of the invasive Harmonia axyridis are not yet completely resolved. Hypotheses predicting positive and independent effects of prey abundance and degree of urbanization on the adult abundance of this species in Central Europe were tested. Populations of H. axyridis were sampled in a period when it was most abundant, by sweeping lime trees (Tilia spp.) at 28 sites along a 20 km transect across urban (western Prague) and surrounding rural areas. The sites differed in aphid abundance (number of Eucallipterus tiliae per 100 sweeps) and degree of urbanization (percentage of the surrounding area within a 500 m radius covered by impervious human constructions). Multiple linear regression analysis of log-transformed data revealed that abundance of H. axyridis (number of adults per 100 sweeps) increased significantly with both aphid abundance (P = 0.015) and urbanization (P = 0.045). The positive relationship between degree of urbanization and abundance of H. axyridis was thus not a side effect of variation in aphid abundance, which was also greater in urban than rural areas. The effect of urbanization might constrict the habitat available to H. axyridis and force this species to aggregate in urban green "refugia". These results point to a plurality of factors that determine coccinellid abundance at natural sites. |
Abnormal development in larvae of Sesamia nonagrioides (Lepidoptera: Noctuidae) resulting from baculovirus-mediated overexpression of a JHE-related gene (SnJHER)Original articleDimitrios KONTOGIANNATOS, Luc SWEVERS, Anna KOURTIEur. J. Entomol. 114: 7-15, 2017 | DOI: 10.14411/eje.2017.002 The Mediterranean corn borer Sesamia nonagrioides (Lepidoptera: Noctuidae) has a unique and recently multiplied juvenile hormone esterase gene family (SnJHER) with particular transcriptional profiles and functional characteristics. Unlike conventional juvenile hormone esterase genes (JHEs), the SnJHER gene family seems to have been recently evolved from a common ancestral JHER gene. SnJHERs seem to be regulated by both ecdysone agonists and xenobiotics, while their real role in development remains to be exploited. In this study we transiently expressed the major SnJHER isoform in Bm5 and Hi5 cell lines. The JHER-expressing cell lines showed increased toxicity when treated with the juvenile hormone analog methoprene. Moreover baculovirus-mediated transient gene transduction of the SnJHER gene in larvae of S. nonagrioides resulted in moulting abnormalities. These were more marked after the additional application of the juvenile hormone analog methoprene. Our results indicate a potential mechanism by which SnJHER interferes with normal JHE. |
Expression of heat-shock protein genes in Apis mellifera meda (Hymenoptera: Apidae) after exposure to monoterpenoids and infestation by Varroa destructor mites (Acari: Varroidae)Original articleNajmeh SAHEBZADEH, Wei Hong LAUEur. J. Entomol. 114: 195-202, 2017 | DOI: 10.14411/eje.2017.024 Heat shock proteins (hsps) protect proteins in eukaryotic cells from damage. Expression of hsps in insects subject to different environmental stimuli is poorly characterized. Here, levels of expression of the hsps genes (hsp40, hsp70, and hsp90) were recorded in Apis mellifera Linnaeus (Hymenoptera: Apidae) workers after exposure to sublethal concentrations of thymol, eucalyptol, α-pinene, trans-anethole, diallyl disulfide and infestation with Varroa mites. Our results show a dose-dependent up-regulation in the levels of all the hsps tested after the bees were treated with thymol, eucalyptol and α-pinene. Although these up-regulated expressions were statistically significant for hsp70 and hsp90 when the bees were treated with thymol and eucalyptol, they were not significant when treated with α-pinene. In addition, significant down-regulated expressions of the hsp genes were recorded in the diallyl disulfide treatment. The transcriptions of all the hsps tested were significantly down-regulated when pupae were infested with different numbers (0-5) of Varroa mites. Thus, it is likely that hsps can be used as biomarkers of survival when honey bees are under toxic and pathogenic stress, but this needs to be confirmed. |
Structure and function of the male ventral organ in Onychiuroides granulosus (Collembola: Onychiuridae)Original articleBo¿ena SIMICZYJEW, Dariusz SKAR¯YÑSKI, Adrian SMOLIS, Romuald J. POMORSKI, Marta MAZURKIEWICZ-KANIAEur. J. Entomol. 115: 134-139, 2018 | DOI: 10.14411/eje.2018.012 On the ventral tube of males of Onychiuroides granulosus (Stach, 1934) there is a male ventral organ, which consists of two groups of four setae that are thickened, slightly flattened and bent. All setae of the male ventral organ are inserted in a richly sculptured cuticle. At the base of each seta there are a few large cells (basal cells) that have large irregular nuclei that contain a large amount of heterochromatin. In the cytoplasm of the basal cells there are numerous mitochondria, ribosomes and a rich system of endoplasmic reticulum. The plasma membrane of the basal cells forms richly folded, deep invaginations, filled with a dense material, which also occurs in particular setae and on their surface. The present study indicates that the male ventral organ is secretory and does not confirm its previously suggested sensory function. |



