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Ecological and molecular diversity of Eulachnini aphids (Hemiptera: Aphididae: Lachninae) on coniferous plants in LithuaniaOriginal articleJekaterina HAVELKA, Jurij DANILOV, Rimantas RAKAUSKASEur. J. Entomol. 117: 199-209, 2020 | DOI: 10.14411/eje.2020.021 Based on research carried out from 2016 to 2018 there are twenty-six species of aphids of the tribe Eulachnini in Lithuania. Seventeen are members of the subgenus Cinara of the genus Cinara, three of the subgenus Cupressobium and two of the subgenus Schizolachnus. In addition, there are four species of the genus Eulachnus. Summarized information on the distribution and host specificity of Eulachnini in Lithuania is presented. Nine species were in all climatic regions of Lithuania: C. (Cinara) brauni, C. (Cinara) hyperophila, C. (Cinara) neubergi, C. (Cinara) piceicola, C. (Cinara) pinea, C. (Cinara) pini, C. (Cinara) pruinosa, C. (Cupressobium) cupressi and C. (Cupressobium) juniperi. Five species of Lithuanian Eulachnini inhabit host plants of the genus Picea, three live on Larix, thirteen on Pinus, one on Abies, one on Thuja and three on Juniperus. Cinara (Cinara) piniphila was recorded on Pinus mugo and C. (Cinara) nuda on Pinus heldreichii for the first time. Partial COI and EF-1α sequences of C. (Cinara) hyperophila, C. (Cinara) pilosa and C. (Cinara) piceicola were obtained for the first time. Partial sequences of mitochondrial (COI) and nuclear (EF-1α) DNA of Lithuanian samples were used to explore molecular diversity using NJ trees, Automatic Barcode Gap Discovery (ABGD), General Mixed Yule Coalescent (GMYC) and Poisson Tree Processes (PTP). Species delimitation using GMYC (both on COI and EF-1α sequences), PTP (BI on COI) and ABGD (EF-1α) were the most consistent with traditional classifications. Pairwise between-species sample divergences (COI and EF-1α fragments) of the samples of the species complex C. (Cinara) pinea - C. (Cinara) piniphila indicate it is composed of a single species. Of the species of aphids that live on conifers, there are seven species of the tribe Eulachnini that are likely to shortly colonize Lithuania. |
The DNA barcoding project on German Diptera: An appreciative and critical analysis with four suggestions for improving the development and reliability of DNA-based identificationOriginal articleMarion KOTRBAEur. J. Entomol. 117: 315-327, 2020 | DOI: 10.14411/eje.2020.037 The progress in constructing a DNA barcode library for German Diptera as published by Morinière et al. (2019, Mol. Ecol. Resour. 19: 900-928) is appraised from a dipterists' perspective. The coverage of the diversity of German Diptera in terms of barcode index numbers (BINs) and identified barcodes is analysed and visualized in simple diagrams. The influence of the project setup, methodology and/or systematic effects on the emerging numbers and trends is elucidated and extensively discussed. In addition, the documentation on the species identification methods in the database is assessed. Based on this evaluation, four ways for improving the future development, utility and reliability of this DNA database and similar projects in general are identified: (1) Sample the collections of experts. This results in a greater and more reliable coverage within a limited time frame, as opposed to random collecting and relying on a posteriori identification. (2) Give priority to medically, agriculturally or ecologically important families. Addressing these gaps will meet the most pressing needs of the community and serve as a good advertisement for the usefulness and wide applicability of the DNA barcode library. (3) Allocate resources to recruiting established experts as opposed to trainees. The fact that half of the recovered BINs remained unidentified mostly results from the insufficient involvement of experts (and expert time). (4) Appropriately document the morphological identifications by experts in the database. This will allow to assess the reliability of DNA-based identifications and to prioritize conflicting identifications within a BIN accordingly. |
Revision of the assassin bug genus Neopirates (Heteroptera: Reduviidae: Peiratinae), with descriptions of two new species from NamibiaOriginal articleYingqi LIU, Zhuo CHEN, Michael D. WEBB, Wanzhi CAIEur. J. Entomol. 117: 343-351, 2020 | DOI: 10.14411/eje.2020.039 The African assassin bug genus Neopirates Miller, 1952, is revised. The type species, N. nyassae Miller, 1952, is redescribed and illustrated; two new species from Namibia, N. bicolor Liu & Cai sp. n. and N. xanthothorax Liu & Cai sp. n. are described and a key is provided to separate the three species of this genus. Sphodrembas fumipennis Swanson, 2019, the type species of Sphodrembas Swanson, 2019, is placed as a junior synonym of N. nyassae, resulting in Sphodrembas becoming a junior synonym of Neopirates. Morphological differences between Neopirates and similar genera and the distribution of Neopirates are briefly discussed. |
The associations between ground beetle (Coleoptera: Carabidae) communities and environmental condition in floodplain forests in the Pannonian BasinOriginal articleJuraj LITAVSKÝ, Oto MAJZLAN, Slavomír STAŠIOV, Marek SVITOK, Peter FEDOREur. J. Entomol. 118: 14-23, 2021 | DOI: 10.14411/eje.2021.002 We studied assemblages of carabids in eight similar habitats, five in Slovakia and three in Serbia. The ground beetles were caught by pitfall traps from February 2015 until November 2016. We compared the incidence of Carabidae in floodplain forests and ecotones alongside the River Danube in Slovakia and the Rivers Tisza and Begej in Serbia. We determined their association with anthropogenic effects,diversity of plants in the different vegetation layers, cover of vegetation layers (herbaceous plants, shrubs and trees), area of forest stands, circumference of forest stands, distance to forest edge, age of forest stands, depth of leaf litter and physico-chemical properties of soil and leaf litter (conductivity, pH, relative content of H, C, P and N). In total, 2,495 adult individuals of 110 species of carabids were collected. The total epigeic activity of the carabids was significantly and positively associated with the number of species of plants in E3 vegetation layer and the relative content of N, and negatively with the cover of the E1 layer. Species richness was significantly positively associated with the number of species of plants in the E3 layer and the pH of leaf litter, but an opposite trend in evenness. |
Temperature differences associated with colour do not determine where the acorn ant Temnothorax crassispinus (Hymenoptera: Formicidae) chooses to nestOriginal articleSławomir MITRUSEur. J. Entomol. 118: 46-50, 2021 | DOI: 10.14411/eje.2021.005 Temperature is an important factor for invertebrates. Social insects build nests, which along with their ability to thermoregulate, provide shelter from extreme temperatures. However, for many species of ants the most common method of controlling the temperature inside a nest is to choose a suitable nest site. During a field experiment, the choice of nest site by the acorn ant Temnothorax crassispinus, a species which lives in coniferous and mixed forests, was studied. It typically occupies ephemeral nest sites and can move to a new nest site several times in one season. It was predicted that in early spring, dark coloured nest sites would be warmer and thus more frequently occupied by ant colonies. Contrary to this prediction, no difference was recorded in the frequency with which dark and lighter coloured nests were occupied. However, also in contrast to the prediction, in forest in early spring the difference in temperature inside different coloured nests was small. Thus, other features of nests, e.g., volume of cavity, are probably more important in determining nest site selection by this ant. |
Three new species of the Xylophanes crotonis species-group (Lepidoptera: Sphingidae) from Colombia and a neotype designation for Xylophanes aristorOriginal articleYenny CORREA-CARMONA, Alessandro GIUSTI, Jean HAXAIRE, Rodolphe ROUGERIE, Ian J. KITCHINGEur. J. Entomol. 118: 64-81, 2021 | DOI: 10.14411/eje.2021.009 Three new species of the hawkmoth genus Xylophanes Hübner, 1819 from Colombia are described based on morphological characters and DNA barcodes: Xylophanes camilae Correa-Carmona & Giusti sp. n., Xylophanes pijao Giusti & Correa-Carmona sp. n., and Xylophanes tayrona Correa-Carmona & Giusti sp. n. The new species are compared with the most morphologically similar species within the informal Xylophanes crotonis species-group: Xylophanes aristor (Boisduval, 1870), Xylophanes crotonis (Walker, 1856) and Xylophanes huloti Haxaire & Vaglia, 2008. Diagnoses, distribution maps, photographs of genital structures and habitus are provided for each new species. In addition, a dichotomous key is provided to identify the new species and the most morphologically similar species within the group. To stabilize the nomenclature and fix the taxon concept, a neotype is designated for Xylophanes aristor. |
Taxonomic notes on the tribe Ectinoderini (Hemiptera: Heteroptera: Reduviidae: Harpactorinae) from the Indochinese PeninsulaOriginal articleZhuo CHEN, Valérie A. LEMAÎTRE, Wanzhi CAIEur. J. Entomol. 118: 225-239, 2021 | DOI: 10.14411/eje.2021.024 The identities of two species of assassin bugs in the tribe Ectinoderini (Hemiptera: Heteroptera: Reduviidae: Harpactorinae) from the Indochinese Peninsula are reviewed, resulting in the following new synonymy and new combinations: Amulius Stål, 1865 = Parapanthous Distant, 1919, syn. n.; Amulius spinicollis (Distant, 1919), comb. n. (transferred from Parapanthous) and Ectinoderus confragosus (Distant, 1919), comb. n. (transferred from Amulius). Lectotypes of these species are designated. The hemelytral venations of Amulius and Ectinoderus Westwood, 1843 are briefly discussed and their diagnoses accordingly revised. Amulius is newly reported from Vietnam and Ectinoderus is recorded from Cambodia for the first time. |
Gastrophysa viridula (Coleoptera: Chrysomelidae) in the Czech Republic: Decline in a once abundant invasive oligophagous consumer of RumexOriginal articleZdenka MARTINKOVA, Alois HONEK, Pavel SASKAEur. J. Entomol. 118: 250-254, 2021 | DOI: 10.14411/eje.2021.026 While the progress of the spread of invasive species of insects in new geographical areas are usually intensively monitored, the decline of these species often escape attention and is poorly documented. In this study, we record the decline in abundance of Gastrophysa viridula (DeGeer), an invasive oligophagous consumer of dock (Rumex spp.). This species originally inhabited Alpine regions. In the late 1800s, G. viridula was recorded in montane areas in the Czech Republic and then throughout this country. Gastrophysa viridula was very abundant in 1995-1999, when we found it in all of the 177 stands of R. obtusifolius inspected in western Czech Republic. In a repeated study of its occurrence in the same area from 2019-2020, this species was present in < 30% of 434 of the stands inspected and was only abundant (≥ 55% of plants in the stand infested by G. viridula) in < 4% of these stands. Thus the local occurrence and abundance of G. viridula had decreased significantly. Of the possible reasons for this decline the most probable are the effect of climate warming on host plant seasonality, changes in agricultural use of grasslands and fragmentation of large stands of dock. |
PCR-based detection of prey DNA in the gut contents of the tiger-fly, Coenosia attenuata (Diptera: Muscidae), a biological control agent in Mediterranean greenhousesOriginal articleSofia G. SEABRA, Joana MARTINS, Patrícia BRÁS, Ana M. TAVARES, Inês FREITAS, António BARATA, Maria Teresa REBELO, Célia MATEUS, Octávio S. PAULO, Elisabete FIGUEIREDOEur. J. Entomol. 118: 335-343, 2021 | DOI: 10.14411/eje.2021.035 The tiger-fly Coenosia attenuata Stein (Diptera: Muscidae: Coenosiini) is a generalist predator that preys on several pests of greenhouse crops and is considered a biological control agent in the Mediterranean region. Previous behavioural observations identified its preferred prey, but a more in-depth evaluation will benefit from using Polymerase Chain Reaction amplification of prey DNA remains in the gut of this predator. To evaluate the rate of decay and suitability of this method for use in the field assessments, we carried out a laboratory feeding calibration experiment on 355 females of C. attenuata, which were killed at different intervals of time after ingestion (10 time points from 0 to 48 h). The prey species tested were: Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae: Trialeurodini), Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), Diglyphus isaea (Walker) (Hymenoptera: Eulophidae: Cirrospilini), Bradysia impatiens (Johannsen) (Diptera: Sciaridae) and Drosophila mercatorum Patterson & Wheeler (Diptera: Drosophilidae: Drosophilini). Based on a probit model, amplification success of prey DNA declined exponentially with increasing time after ingestion. The half-time molecular detection differed between species, ranging from an average of 5 h for T. vaporariorum and D. isaea, 6 h for B. impatiens, 15 h for L. huidobrensis to more than 40 h for D. mercatorum. This study confirmed the feasibility of using DNA based detection to identify prey species in the gut contents of C. attenuata and provided calibration curves for a better understanding of predation activity in this agroecosystem. |
Arthropod fauna recorded in flowers of apomictic Taraxacum section RuderaliaOriginal articleAlois HONĚK, Zdenka MARTINKOVÁ, Jiří SKUHROVEC, Miroslav BARTÁK, Jan BEZDĚK, Petr BOGUSCH, Jiří HADRAVA, Jiří HÁJEK, Petr JANŠTA, Josef JELÍNEK, Jan KIRSCHNER, Vítězslav KUBÁŇ, Stano PEKÁR, Pavel PRŮDEK, Pavel ŠTYS, Jan ŠUMPICHEur. J. Entomol. 113: 173-183, 2016 | DOI: 10.14411/eje.2016.021 Flowers of dicotyledonous plants host communities of arthropod species. We studied the community associated with dandelion (Taraxacum section Ruderalia), a complex of apomictic micro-species abundant in central Europe. Identification of microspecies in the field was impracticable. These plants produce an abundance of flowers that host arthropod communities that are not yet fully documented. We investigated species occurrence, its diurnal and seasonal variation and some of the factors that determine the abundance of the dominant species. Insect and spiders were collected from 2010 to 2012 at a locality in Prague. Whole capitula were harvested at weekly intervals and resident arthropods were identified. Diurnal variation in insect presence and the effect of pollen and microclimate on some of the species were also examined. The insect community (> 200 species) consisted mainly of species of Hymenoptera (86 spp.), Coleoptera (56 spp.), Diptera (46 spp.) and Heteroptera (23 spp.). The most abundant were Thysanoptera (2 spp.). Pollen eaters/collectors and nectar feeders dominated over predators and occasional visitors. From April to mid-August, the insect community was dominated by Coleoptera, and later by Diptera and Hymenoptera. Except for Meligethes spp. and species breeding in the capitula, the insects occupied flowers during the daytime when the flowers were open (10-12 h in spring and only 2-4 h in late summer). The presence of Meligethes spp. in particular flowers was associated with the presence of pollen; the occurrence of Byturus ochraceus with pollen and flower temperature. Although pollination is not necessary, dandelion plants produce both nectar and pollen. The community of arthropods that visit dandelion flowers is rich despite their being ephemeral. The composition of local faunas of flower visitors, presence of floral rewards and flower microclimate are important factors determining the composition of the flower community. |
First North American record of an unnamed West Palaearctic Agrilus (Coleoptera: Buprestidae) infesting European beech (Fagus sylvatica) in New York City, USAOriginal articleMarc F. DIGIROLOMO, Eduard JENDEK, Vasily V. GREBENNIKOV, Oto NAKLÁDALEur. J. Entomol. 116: 244-252, 2019 | DOI: 10.14411/eje.2019.028 This paper reports a non-native Agrilus wood-boring jewel beetle reared from a stressed and non-native European beech (Fagus sylvatica) tree growing in New York City, USA. Results of two analyses using 759 DNA barcodes of Agrilus corroborate the morphology-based interpretation that this is the first North American record of an unnamed species from the A. roscidus species-group native to the Western Palaearctic. Taxonomy of the entire species-group requires revision, therefore we postpone formal description of the new species and refer to it as Agrilus sp. 9895. This is the 12th non-native Agrilus established in North America. Prior to our study, members of the A. roscidus species-group were not known to develop in Fagus, therefore we hypothesise whether our record is a host plant shift linked to the human-mediated transatlantic dispersal, or a case of an elusive beetle escaping detection in Fagus in its unknown native range. All 759 herein analysed DNA barcodes of Agrilus (including, when present, specimen images and georeferences) are available online at dx.doi.org/10.5883/DS-VGDS010. |
Current and predicted distribution of the rare and threatened beetle Bolbelasmus (Bolbelasmus) unicornis (Coleoptera: Geotrupidae) in SerbiaOriginal articleSrećko ĆURČIĆ, Dragan PAVIĆEVIĆ, Dejan RADOVIĆ, Nikola VESOVIĆ, Rostislav BEKCHIEV, Nina ĆURČIĆ, Borislav GUÉORGUIEVEur. J. Entomol. 116: 413-424, 2019 | DOI: 10.14411/eje.2019.042 Bolbelasmus (Bolbelasmus) unicornis (Schrank, 1789) (Coleoptera: Geotrupidae) is a rare and threatened beetle distributed mostly in Central, Eastern and Southeast Europe. As a species of special conservation significance it is included in Annexes II and IV of the Habitat Directive of the European Union. Several new records of this species documented using light traps and soil sampling were recently reported in Serbia (the central part of the Balkan Peninsula). In this paper we present and discuss the current distribution of this species in the region studied based on GIS occurrence data. The distribution is mapped and values of environmental variables within this beetle's range are quantified using GIS technology. In addition, we predict its potential range in Serbia using a model based on the current distribution of this beetle, environmental variables and distribution of its food source. |
Oviposition preference maximizes larval survival in the grass-feeding butterfly Melanitis leda (Lepidoptera: Nymphalidae)Original articleFreerk MOLLEMAN, Sridhar HALALI, Ullasa KODANDARAMAIAHEur. J. Entomol. 117: 1-17, 2020 | DOI: 10.14411/eje.2020.001 Phytophagous insects may be expected to prefer host-plant species on which their larvae perform best, but this has rarely been explored in grass-feeding butterflies. We explored links between oviposition preferences, larval food preferences, and performance (larval survival and development time, pupal mass, and adult longevity) on 18 species of grass in the common evening brown, Melanitis leda L. (Nymphalidae: Melanitini), a tropical butterfly that has been recorded from a large number of species of grass. Melanitis leda oviposited on all of the grass species offered in choice experiments, and larvae were able to develop to the adult stage on almost all of them. Oviposition preferences were for species of plants on which larval survival was higher, but were not correlated with larval development. The mother's choice of host plant appeared to affect performance of the resulting adults as large butterflies had longer life spans. Ovipositing females appeared to adjust clutch size and position of their eggs on a plant depending on plant traits. Larval survival was only marginally correlated with larval growth rate on the different species of plants. Larvae showed host-plant preferences that were not correlated with adult oviposition preferences, larval survival, or larval growth. Overall, while M. leda can utilize a large number of species of grass, it shows marked oviposition preferences. Apparent fine-tuning of clutch size and positioning of eggs on plants with different traits might be another adaptation associated with using a large number of species of plants. We conclude that this grass feeding butterfly selects oviposition sites that maximize the chances of their larvae surviving. |
Taxonomic and functional differentiation of spiders in habitats in a traditional olive producing landscape in ItalyOriginal articleMalayka S. PICCHI, Gionata BOCCI, Ruggero PETACCHI, Martin H. ENTLINGEur. J. Entomol. 117: 18-26, 2020 | DOI: 10.14411/eje.2020.002 Annual crops are generally assumed to host simplified arthropod communities that depend on immigration from the surrounding landscape. Perennial, low-input crops such as olive groves are likely to depend less on immigration from other habitats, however, studies on the landscape ecology of perennial crops are scarce. This paper studies the assemblages of arboreal spiders in three types of habitats adjoining olive groves: woods, garigue and other cultivated olive groves in a traditional olive producing landscape. Spiders were sampled during summer and the three types of habitats were compared in terms of species, families and functional groups in order to determine differences in diversity and the potential for spider spillover. As is often reported for annual crops, olive groves had a lower alpha and beta diversity than more natural habitats in terms of species, with a strong dominance of a single species, Frontinellina frutetorum (C.L. Koch, 1834). Differences in diversity between olive groves and natural habitats were not significant at family or functional group levels. With the possible exception of orb weavers, this study indicates that the spiders that were common in olive groves did not occur at higher densities in habitats that were more natural. This indicates there is limited spillover between perennial crops and other late-successional habitats. The enhancement of spiders in olive orchards for pest control may thus depend more on local management than on the presence of semi-natural habitats as a source of immigration. |
Long term changes (1990-2016) in carabid beetle assemblages (Coleoptera: Carabidae) in protected forests on Dinaric Karst on Mountain Risnjak, CroatiaOriginal articleŽeljka JAMBROŠIĆ VLADIĆ, Lucija ŠERIĆ JELASKAEur. J. Entomol. 117: 56-67, 2020 | DOI: 10.14411/eje.2020.006 Carabids, as well-known bioindicators, have been used to study the long term changes that have occurred in their communities in the Dinaric Alps. This study involved eight sites in the protected forests of the Risnjak National Park in the years 2015 and 2016 of which three were previously studied in 1990 and 1991. A total of 9, 521 individual ground beetles belonging to 17 genera and 33 species were collected. Species diversity and community composition, including percentages of species grouped according to their habitat preferences, body size, wing morphology, preferred moisture and temperature were used to compare the sites sampled in 1990 and 1991 and resampled in 2015 and 2016. Even though this study was carried out in protected forests within the National Park with minimal anthropogenic pressure and the fact that available climatic data didn't show any significant change in climate over the last 25 years, there was a reduction in the abundance of specialist species and increase in the spread of generalist species. Furthermore, the lower abundance of a mountain specialist and endemic species, Pterostichus variolatus, and the lack of mountain specialists Molops alpestris, Pterostichus unctulatus and Trechus croaticus in the catches indicate the importance of further monitoring of these mountain forest ecosystems and for a well-timed and appropriate conservation approach. |
Volatile production differs between oak leaves infested by leaf-miner Phyllonorycter harrisella (Lepidoptera: Gracillariidae) and galler Neuroterus quercusbaccarum (Hymenoptera: Cynipidae)Original articleFabian S. KLIMM, Alexander WEINHOLD, Martin VOLFEur. J. Entomol. 117: 101-109, 2020 | DOI: 10.14411/eje.2020.011 Plants defend themselves by producing various volatile organic compounds (VOCs) that have direct and indirect effects on insect herbivores. Their production is often specific to the plant and herbivore species involved, with some herbivores being able to manipulate their production. Here, we used passive volatile sampling using polydimethysiloxane (PDMS) tubing to compare VOCs produced by control, mined and galled oak leaves in the field. Leaves mined by a microlepidopteran leaf-miner (Phyllonorycter harrisella) produced a lower amount of two sesquiterpenes and an increased amount of eucalyptol. In contrast, leaves galled by the gall wasp (Neuroterus quercusbaccarum) did not produce a lower amount of any of the VOC measured when compared to the control. They produced a higher amount of farnesene, β-bourbonene and eucalyptol. Some of these VOC are known for their anti-herbivore function. In a second experiment, we treated the experimental leaves with the phytohormone methyl jasmonate (MeJA) to determine if leaf-miners or gallers reduced the overall inducibility of infested leaves. MeJA induced a sixteen-fold increase in VOC production. However, there was no difference in VOC production of control, mined and galled leaves treated with MeJA. Our results show that up- and down-regulation of VOCs can vary among leaves infested by different herbivores. More experiments are needed to determine if this is due to manipulation by the herbivores themselves or due to a defensive response of the plant. |
Facultative symbionts associated with aphid populations in citrus orchards in northern TunisiaOriginal articleFrançois RENOZ, Inès PONS, Christine NOËL, Kaouthar LEBDI-GRISSA, Vincent FORAY, Thierry HANCEEur. J. Entomol. 117: 149-156, 2020 | DOI: 10.14411/eje.2020.017 Like many insects, aphids (Hemiptera: Aphididae) can host a wide diversity of symbiotic bacteria that can be important drivers of their evolutionary ecology. In addition to the nutritional obligate symbiont Buchnera aphidicola, these phloem-sap feeding insects can host various facultative symbionts whose functional diversity depends on complex interactions with the host genotype and environmental factors. During sampling in citrus orchards in northern Tunisia, we collected aphids on citrus plants. The specimens belonged either to the cotton-melon aphid Aphis gossypii or the green citrus aphid Aphis spiraecola. We analysed the prevalence of Arsenophonus, Serratia symbiotica, Hamiltonella defensa and Regiella insecticola, four facultative symbionts frequently found in the genus Aphis and potentially associated with phenotypic effects related to nutrition, protection against parasites and tolerance of high temperatures. We found that the diversity and prevalence of facultative symbionts differed between these two aphid species that exploit similar ecological niches. In particular, we found a high prevalence of Arsenophonus in A. gossypii populations and that the defensive symbiont H. defensa was only present in A. spiraecola populations. These results are discussed in light of the ecology and life cycles of each of the species of aphid studied. |
Using sentinel prey to assess predation pressure from terrestrial predators in water-filled tree holesOriginal articleMartin M. GOSSNER, Elena GAZZEA, Valeriia DIEDUS, Marlotte JONKER, Mykola YAREMCHUKEur. J. Entomol. 117: 226-234, 2020 | DOI: 10.14411/eje.2020.024 Tree-related microhabitats are important for forest biodiversity. Water-filled tree holes are one such microhabitat and can be abundant in temperate forests. The arthropod community in this microhabitat not only contribute to forest biodiversity but also provides food for terrestrial predators such as arthropods, small mammals and birds. The extent of the threat of attack from terrestrial predators on insect larvae in this microhabitat, however, is poorly known. To measure predation in this microhabitat, we produced fake prey resembling insect larvae using white plasticine and exposed them at the aquatic-terrestrial habitat interface. We recorded: (1) which predators attacked the fake larvae, (2) the predation probability on the fake larvae after two days and after two weeks and (3) whether predation probability on fake larvae differed between managed and unmanaged forest zones in one of the last primeval beech forests, the Uholka division of the Carpathian Biosphere Reserve in the Ukrainian Carpathians. By addressing these questions, we aimed to quantify the predation pressure of terrestrial predators on insect larvae in tree-holes. The probability that a fake larva in a tree hole was attacked by predators ranged between 25-58% (95% CI) after two days and between 76-96% (95% CI) after two weeks. Overall, the highest attack rates were recorded for small mammals, followed by arthropods and birds. Arthropods took longer to detect potential prey items than small mammals and birds, and they were the only group that showed significant differences in attack rates between forest zones (unmanaged > managed). This study revealed that sentinel prey might be a suitable method for measuring the predation pressure from terrestrial predators on insect larvae in water-filled tree holes. |
Chenicoris dilatatus, a remarkable new genus and new species of assassin bug (Hemiptera: Heteroptera: Reduviidae: Harpactorinae) from southern ChinaOriginal articleZhuo CHEN, Jianyun WANG, Hu LI, Wanzhi CAIEur. J. Entomol. 117: 252-259, 2020 | DOI: 10.14411/eje.2020.027 Chenicoris dilatatus gen. n. & sp. n. from southern China is described and placed in the largest assassin bug subfamily Harpactorinae (Hemiptera: Heteroptera: Reduviidae). The new species is similar to members of Isyndus Stål, 1859 in general habitus, but can be distinguished from the latter by the unarmed anterior pronotal lobe, the laterally dilated lobe-like abdominal segment V and several features of its genitalia. |
Diversity of Scarabaeinae (Coleoptera: Scarabaeidae) in an urban fragment of Cerrado in Central BrazilOriginal articleMarina R. FRIZZAS, João L.F.L. BATISTA, Marcus V.C. ROCHA, Charles M. OLIVEIRAEur. J. Entomol. 117: 273-281, 2020 | DOI: 10.14411/eje.2020.031 The diversity of dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) is affected by urbanization, habitat fragmentation and disappearance of native mammals, which result in changes in the quality and availability of food, and resources for nesting. We evaluated the diversity, distribution of species in different trophic guilds and foraging strategies, and temporal variation in abundance of dung beetles in an urban fragment of Cerrado in a Federal District of Brazil. This study was conducted at the Experimental Station of Biology (EEB) of the University of Brasília (UnB), Federal District, Brazil. Fortnightly, between October 2012 and September 2013, Scarabaeinae were collected using baited (human faeces, pig meat, or banana) and unbaited pitfall traps. Aspects of the dung beetle assemblage were evaluated, including species richness and abundance, feeding habits and foraging strategies. A total of 614 individuals were collected, which included eight species belonging to seven genera and four tribes. Dichotomius carbonarius (Mannerheim, 1829), a generalist species, dominated the assemblage, indicating that it is adapted to living in fragmented and urbanized areas. As regards feeding habits, Eurysternus caribaeus (Jablonsky & Herbst, 1789) was considered to be strictly coprophagous, Coprophanaeus cyanescens (d'Olsoufieff, 1924) copronecrophagous and D. carbonarius a generalist. Most species were classified as paracoprids, which accounted for 75% of the species collected. Regarding the attractiveness of the bait, the highest numbers of individuals and species were recorded in pitfall traps baited with human faeces. A high abundance of Scarabaeinae was recorded in the first half of the rainy season (October-December) with 98.2% of the individuals collected in this period. The urban area studied harboured a low number of species with high abundance of a few species. |
Influence of forest decline on the abundance and diversity of Raphidioptera and Mecoptera species dwelling in oak canopiesOriginal articleAlexis VINCENT, Pierre TILLIER, Cécile VINCENT-BARBAROUX, Christophe BOUGET, Aurélien SALLÉEur. J. Entomol. 117: 372-379, 2020 | DOI: 10.14411/eje.2020.041 Trees in a state of decline exhibit a reduced foliage density and accumulate dead branches in their crowns. Consequently, forest decline can markedly affect both the habitats and sources of food for canopy-dwelling insects. The decline-induced increase in canopy openness may also modify the understory, shrub and ground layers, and have cascading effects on associated species. Flight interception traps and green Lindgren traps were used to survey the canopy-dwelling insects in stands of healthy and declining oak trees, in particular two insect orders: Raphidioptera, saproxylic insects associated with canopies, and Mecoptera, necrophagous or opportunistic species associated with the herbaceous or shrub strata. Overall, green Lindgren traps caught more of these insects than flight interception traps. The traps caught five species of Raphidioptera. Three of them, Subilla confinis, Phaeostigma major and, to a lesser extent, Phaeostigma notata, were more abundant in stands or plots with declining trees. However, the other two species of Raphidioptera, Atlantoraphidia maculicollis and Xanthostigma xanthostigma exhibited a reverse trend. Two species of Mecoptera, Panorpa germanica and Panorpa communis, were particularly abundant, but unaffected by the level of decline. Our results show that declining forests can either host more or fewer species of Raphidioptera with saproxylic larvae, whereas Mecoptera with ground-living larvae were unaffected. Seasonal phenology and sex ratio of the species are also discussed. |
Carabid beetles (Coleoptera: Carabidae) in several types of forests on Hokkaido, Japan, with implications for forest management practices and beetle preservationOriginal articleJun KAIZUKA, Tamaki YAMAGUCHI, Mitsuhiro IWASAEur. J. Entomol. 117: 400-408, 2020 | DOI: 10.14411/eje.2020.044 This study of the role the environment in the composition of the communities of carabid beetles was carried out in several types of forests at Obihiro and Furano, Hokkaido, Japan. In addition, we analysed the altitudinal distributions of two forest specialists, Damaster gehinii (Faimaire) and Procrustes kolbei Roeschke, which occur in six mountain forests on Hokkaido. At Obihiro, the forest specialist, P. kolbei was found at only one site in a large area of broadleaf forest. A redundancy analysis indicated that the carabid assemblages were significantly different in the different types of forest, and that two species, Leptocarabus arboreus arboreus (Lewis) and Leptocarabus opaculus opaculus (Putzeys), were associated with broadleaf forests. At Furano, a forest specialist D. gehinii and a forest generalist Cychrus morawitzi Gehin were mainly collected in natural broadleaf and mixed forests, whereas the percentage made up of L. o. opaculus was very high (80.8%) in natural broadleaf forest. Pterostichus thunbergii Morawitz made up the highest percentage of the species in the conifer plantations. In the six mountain forests, D. gehinii was scarce and mainly occurred at low altitudes; however, P. kolbei was relatively abundant and mainly recorded at middle to high altitudes. The management of the forests on Hokkaido needed to maintain the diversity and abundance of carabid beetles is discussed. |
Does the shrub layer act as an intermediary? Effects on abundance of insects and abundances of particular insect orders caught flying in the canopies of deciduous forests in Central GermanyOriginal articleStephanie STIEGEL, Anna KORFHAGE, Jasmin MANTILLA-CONTRERASEur. J. Entomol. 117: 409-419, 2020 | DOI: 10.14411/eje.2020.045 Scientists and society are increasingly becoming aware of loss of insect biodiversity and biomass. The level of biodiversity determines the efficiency of ecological communities to capture essential resources, produce biomass, decompose and recycle nutrients. Relationships between plant and insect diversity can be modified by changes in insect abundance. This study determined the associations between microclimate and diversity of forest plants on overall insect abundance and abundances of different insect orders in the canopy of temperate deciduous forests dominated by Fagus sylvatica L. (European beech; Fagaceae) in Central Germany. Following model selection, a linear mixed model was used to analyse the associations between abiotic factors (air temperature and relative humidity) as well as biotic factors (species richness and cover for the ground, shrub and tree layer) and insect abundance and abundances of insect orders. Within similar strength of evidence, best models were chosen as those with a single explanatory parameter. Significant associations were recorded between abundances of Lepidoptera and Neuroptera and relative air humidity, insect abundance and species richness in the shrub layer, and between abundances of Diptera and Psocoptera and percentage cover of shrubs. Trends in associations were detected between the abundance of Hemiptera and species richness recorded in the shrub layer, and between the abundance of Thysanoptera and the species richness in the ground layer. No significant associations with single explanatory parameters were recorded for the abundances of Coleoptera and Hymenoptera. Phytodiversity, especially that in the shrub layer, were more often associated with the abundances of insect orders than microclimatic factors. The potential importance of the association between shrub layer parameters and the abundance of insects might be based on the shrub layer combining the associations with the ground layer (bottom-up processes) and canopy layer (environmental conditions). In addition, associations between phytodiversity and abundance of insects seem to vary most for Coleoptera and Hymenoptera in which there are markedly different functional groups. |
Measuring saproxylic beetle diversity in small and medium diameter dead wood: The "grab-and-go" methodAnna L.M. MACAGNO, Sönke HARDERSEN, Gianluca NARDI, Giuseppe LO GIUDICE, Franco MASONEur. J. Entomol. 112 (3): 510-519, 2015 | DOI: 10.14411/eje.2015.049 Saproxylic organisms play a key role in a variety of forest ecosystem functions, which result in an increase in overall forest productivity and biodiversity. At present, dead wood is frequently removed from exploited forests. Estimating the effect of current forest management on biodiversity, and what gain in biodiversity would result from implementing restoration programs, requires the use of standardized sampling protocols. These protocols need to be suitable for use in different sampling areas and cost effective. In this paper, we developed, tested, and optimized a method for sampling saproxylic insects during a single visit to a sample site (i.e., the "grab-and-go" method). In the spring of 2011, we collected samples of downed decaying small and medium diameter wood debris in two Italian beech forests: Sega di Ala (Alps) and Vallombrosa (Apennines). We used ex situ emergence traps in the laboratory to collect the beetles emerging from the wood sampled. At both sites, the minimum number of wood samples that resulted in a satisfactory description of the saproxylic beetle assemblage was 20. Wood moisture, mean diameter, and geographical location were significantly associated with the beetle assemblages. We discuss the implications of using the "grab-and-go" method in large-scale forest monitoring programs. In this context, we recommend collecting at each site twenty 50 cm-long samples of wood lying on top of the litter, with a diameter of 12 ± 2 cm, cortex cover < 50%, and at Hunter's stage of decay class 2. |
Feeding behaviour of young larvae of Pieris rapae crucivora (Lepidoptera: Pieridae) and its effect on parasitism by Cotesia glomerata (Hymenoptera: Braconidae)Original articleAya NAKAYAMA, Keiji NAKAMURA, Jun TAGAWAEur. J. Entomol. 115: 380-386, 2018 | DOI: 10.14411/eje.2018.038 We investigated the effect of the feeding behaviour of young larvae of Pieris rapae crucivora Boisduval (Pieridae) on parasitism by the parasitoid wasp, Cotesia glomerata (L.) (Braconidae). Young, 1st-3rd instar larvae used approximately three sites for feeding each day. When not feeding, they moved a short distance away from the feeding sites (= feeding marks) and rested. For first, second and third instar larvae, the distances from the new mark, made within 24 h, to larva at rest were, respectively, about 3.5 mm, 5 mm and more than 10 mm. To resume feeding, they moved back to one of the former feeding sites or a new site. The percentage of the feeding marks older than 24 h that attracted parasitoids was less than 50%. Time spent searching for hosts by a parasitoid was short. Larvae placed 5 mm or more from a feeding mark were less parasitized than the larvae placed near a mark. The number of feeding marks affected parasitism. When comparing single-marked and triple-marked leaves, the percentage parasitism of the larvae on the latter was significantly lower than that of the larvae on the former. On triple-marked leaves, parasitoids visited each mark unevenly. Accordingly, the time spent searching each mark differed significantly among the marks. Because of this confusing effect, hosts are considered to be reducing the risk of parasitism. Our results demonstrate that the feeding habits of young larvae of P. rapae crucivora are adaptive in terms of reducing the risk of parasitism by C. glomerata. |
Effects of larval diapause and the juvenile hormone analog, fenoxycarb, on testis development and spermatogenesis in the wax moth, Galleria mellonella (Lepidoptera: Pyralidae)Original articlePiotr BEBAS, Bronislaw CYMBOROWSKI, Michalina KAZEK, Marta Anna POLANSKAEur. J. Entomol. 115: 400-417, 2018 | DOI: 10.14411/eje.2018.040 Facultative diapause in the wax moth, Galleria mellonella, occurs in the final larval instar. Application of juvenile hormone analogs (JHAs) to the larvae of this species has similar effects to diapause, in terms of prolonged development of the larval stages and the arrest in the metamorphosis of internal organs. Here, we focus on testes development and spermatogenesis at the end of larval development in G. mellonella, how they are affected by diapause induced by an environmental decrease in temperature to 18°C and the application of a JHA (fenoxycarb) to larvae. Because neither testis development nor spermatogenesis are described in detail for this species, we examined them in individuals not in diapause during the period from the last larval instar to the newly emerged adult and present a timetable of changes that occur in the development of testes in this species. These observations have increased the very limited data on the course of spermatogenesis in pyralid insects. We then used these data for comparative analysis of testes in larvae from two experimental groups: individuals in diapause and those treated with fenoxycarb. The results on the general morphology testes revealed obvious degenerative changes caused by fenoxycarb (but not by diapause), including testicular wall hypertrophy and disarrangement of testicular follicles. Moreover, treatment with fenoxycarb finally resulted in the disintegration of nearly all testicular cyst-containing germ cells at different stages of spermatogenesis, a situation never previously described in the literature. In contrast, the main effect of diapause on testes was merely the degeneration of spermatocytes in the proximal regions of the testicular follicles. Finally, the TUNEL analyses, revealed that the degenerative changes in germ cells were apoptotic in character in the testes of both individuals in diapause and fenoxycarb-treated males. |
Vitamin D1 versus ecdysteroids: Growth effects on cell regeneration and malignant growth in insects are similar to those in humansPoint of viewKarel SLÁMAEur. J. Entomol. 116: 16-32, 2019 | DOI: 10.14411/eje.2019.003 Polyhydroxylated derivatives of 6-keto,7-dehydrocholesterol (ecdysteroids) are common constituents of various plants. In 1965, they were accidentally discovered in the search for the insect moulting hormone. These biologically important natural compounds are neither insect hormones nor inducers of insect ecdysis. Due to their strong anabolic, vitamin D-like effects in insects, domestic animals and humans, I propose the use of the arbitrary term vitamin D1. The present paper describes the effects of vitamin D1 on the growth and regeneration of excised epidermal cells of the tobacco hornworm, Manduca sexta (Sphingidae). The periods of programmed cell death and cell proliferation (histolysis and histogenesis, respectively) exactly coincide in insects with endogenous peaks of increased concentration of vitamin D1. Epidermal cells communicate with each other, creating a mutually integrated tissue, connected by mechanical, chemical, electrical, ionic or other so far incompletely known factors. After natural cell death, or after the artificial removal of some epidermal cells, the neighbouring cells that lose communication integrity, begin to divide mitotically to replace the disconnected part. Cell divisions are arrested as soon as the integrity of the living tissue is established. During insect ontogeny, the application of juvenile hormone causes regenerating epidermal cells to repeat the previous morphogenetic programme (i.e., development of patches of larval tissue on the body of a pupa, or metathetely). Conversely, the application of vitamin D1 (20-hydroxyecdysone) caused the regenerating cells to prematurely execute a future morphogenetic programme (i.e., development of patches of pupal tissue on the body of a larva, or prothetely). Among the key features of insect regeneration, is the arrest of cell divisions when tissues resume living cell-to-cell integrity. This prevents the formation of aberrant groups of cells, or tumours. It is well established that the main physiological systems of insects (e.g., circulatory, respiratory, neuro-endocrine) are structurally and functionally similar to corresponding systems in humans. Thus the basic principles of cell regeneration and the role of vitamin D1 in insects may also be valid for humans. The common vitamins D2 (ergocalciferol) or D3 (cholecalciferol), are exclusively lipid soluble secosterols, which require activation by UV irradiation and hydroxylation in the liver. By contrast, the neglected vitamin D1 is a natural derivative of polyhydroxylated 7-dehydrocholesterol of predominantly plant origin, which is both partly a water and partly a lipid soluble vitamin. It neither requires UV irradiation, nor hydroxylation due to 6 or 7 already built-in hydroxylic groups. Like other vitamins, it enters insect or human bodies in plant food or is produced by intestinal symbionts. Vitamin D1 causes strong anabolic, vitamin D-like effects in domestic animals and in humans. I am convinced that avitaminosis associated with a deficiency of vitamin D1 in human blood may be responsible for certain hitherto incurable human diseases, especially those related to impaired nerve functions and somatic growth, aberrant cell regeneration |
One step closer to understanding the ecology of Cameraria ohridella (Lepidoptera: Gracillariidae): The effects of light conditionsOriginal articleRadosław JAGIEŁŁO, Edward BARANIAK, Marzenna GUZICKA, Piotr KAROLEWSKI, Adrian ŁUKOWSKI, Marian Jędrzej GIERTYCHEur. J. Entomol. 116: 42-51, 2019 | DOI: 10.14411/eje.2019.005 Horse chestnut leaf miner (Cameraria ohridella) has achieved ecological success by colonizing the entire European range of its primary host, horse chestnut (Aesculus hippocastanum). This insect has attracted the attention of scientists, but its ecology is poorly understood. Here, we investigated the effects of varying degrees of light availability on the leaf morphology of horse chestnut saplings and the performance of C. ohridella. A pot experiment under greenhouse conditions was performed in which the photosynthetic photon flux density (PPFD) was reduced from full light by 50% (high light - HL) or 80% (low light - LL). Insect performance parameters were quantified (i.e., pupal mass, efficiency of conversion of utilised leaf tissue (ECU) and potential fecundity). Compared with HL leaflets those from LL were characterised by higher contents of nitrogen and water but lower total phenolics. The oxidative capacity of phenolics (at pH ≈ 10, common in the lepidopteran gut) was low and did not differ in the two treatments. Compared with those collected from HL leaves, the mines of those collected from leaves of plants grown under LL conditions were larger in area but the leaf mass utilized by larvae was similar. Pupae were heavier in LL than in HL conditions, and ECU was higher in LL. The potential fecundity of females was not sensitive for experimental treatment. We conclude that (1) reduced light had a strong beneficial effect on the performance of C. ohridella and (2) phenolics in A. hippocastanum leaf tissues are a poor defence against this herbivore. |
First DNA analysis of pill scarabs (Coleoptera: Hybosoridae: Ceratocanthinae) reveals multiple paraphyly of Afrotropical PhilharmostesOriginal articleVasily V. GREBENNIKOVEur. J. Entomol. 116: 52-63, 2019 | DOI: 10.14411/eje.2019.006 This paper is the first attempt to resolve relationships among the Ceratocanthinae: Ceratocanthini pill scarab beetles using DNA sequences. It is focused on the Philharmostes group of seven Afrotropical genera: Baloghianestes (3 spp.), Callophilharmostes (1 sp.), Carinophilharmostes (1 sp.), Chaetophilharmostes (1 sp.), Cryptophilharmostes (3 spp.), Petrovitzostes (1 sp.) and Philharmostes (31 spp.). A phylogenetic analysis of 46 terminals and alignment of 2,913 bp from one mitochondrial and two nuclear fragments corroborates monophyly of this group, but rejects that of Philharmostes, the largest genus. The latter is paraphyletic with respect to at least four other smaller genera and consists of at least three distantly related clades. One of them, formed by Philharmostes ballerioi sp. n. from the Tanzanian Nguru (the type locality) and Kaguru Mountains, is sister to the rest of the entire Philharmostes group. The nominal genus Philharmostes is, therefore, a waste-basket taxon for accommodating members of this group that lack the distinct characters of the smaller genera. Pending further research, the phylogenetically inadequate generic taxonomy of the Philharmostes group is not modified. Molecular clock analysis estimates separation of the mitochondrial lineages of two known populations of the new species at about 2.2 Ma, which corresponds with recurring shrinkage and expansion of African rainforest caused by climatic fluctuations during the Pleistocene. Adults of all nominal ingroup genera are illustrated along with male and female body parts of the new species. Diagnostic and/or synapomorphic morphological characters of the Philharmostes group of genera are revised. Habitus images and other supplementary information on all sequenced specimens are available online at dx.doi.org/10.5883/DS-VGDS001 and dx.doi.org/10.5883/DS-VGDS004. |
The role of larval substrate specialization and female oviposition in mediating species diversity of closely-related sepsid flies (Diptera: Sepsidae)Original articleAmelie LAUX, Alexandra WEGMANN, Jeannine ROY, Natalia GOURGOULIANNI, Wolf U. BLANCKENHORN, Patrick T. ROHNEREur. J. Entomol. 116: 75-84, 2019 | DOI: 10.14411/eje.2019.008 Coprophagous insect communities play a critical role in the decomposition of vertebrate dung and provide ecosystem functions fundamental to modern agriculture. While the ecology of dung beetles is rather well understood, niche differentiation in coprophagous flies is poorly studied. Sepsid flies (Diptera: Sepsidae) are a vital part of the European community of coprophages, with 6-7 widespread species of Sepsis often found co-occurring in the same pasture. To advance our ecological understanding of the mechanisms that enable species to coexist, we investigated the oviposition preferences and larval performance of 7 common species of Sepsis in the dung of different large domestic and wild mammals. Substrate preferences and subsequent performance of larvae in laboratory experiments did not vary greatly. All species did very well on cow dung, the most common substrate in Central Europe, but also on dung of horse and wild boar. In contrast, flies did not prefer or grow well in dung of red and roe deer, two of the most common wild vertebrates. Thus there were only minor differences among the species tested along the specialist-generalist (dung) gradient, indicating that differences in the choice of oviposition sites by the adults of the different fly species and larval performance do not constitute a major axis of ecological differentiation. Nevertheless, there was a positive correlation between substrate choice and larval performance indicating the preference of gravid females for particular oviposition sites is adaptive. We conclude that sepsids are common in Europe because they are well adapted to the dung of herbivorous livestock rather than wild animals. Nevertheless, specialization on particular types of dung does not define the niche of Sepsis dung flies and hence plays a minor role in mediating their species diversity. |



