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Results 31 to 60 of 825:

Experimental and comparative analysis of masquerade in flea beetles (Coleoptera: Chrysomelidae)Original article

Tadashi SHINOHARA, Alexander S. KONSTANTINOV

Eur. J. Entomol. 121: 296-302, 2024 | DOI: 10.14411/eje.2024.031

Prey animals employ masquerade to avoid recognition by visual predators by developing a resemblance to inedible objects in their environment. Phytophagous flea beetles seem to resemble models of their own manufacture. While feeding they cause light- or dark-coloured hole-like damage on the leaves of their host plants that resembles the beetle's body in colour and size. Resemblance to the model and the frequency of the model can influence the efficiency of masquerade. To examine masquerade efficiency in light- and dark-coloured beetles, we evaluated their survival benefits from resembling feeding damage in the field. This was done by using two species of beetle of different colour as prey and a jumping spider as the predator. Dark-coloured species were more likely to avoid predation when they were placed on a background with damage similar in colour to their body, whereas increased survival was not recorded for light-coloured species. The extent of the feeding damage of 34 light- and dark-coloured species of beetle was compared. Variation in the extent of the damage was associated more with host plant taxa than beetle body colour. These results indicate that the efficiency of masquerade can vary among beetle species and/or phenotypes.

Exploring the relationship between characteristics of forest stands and the behaviour of Lymantria dispar (Lepidoptera: Erebidae) from a temporal and spatial perspectiveOriginal article

Flavius BÃLÃCENOIU, Dragoș TOMA, Constantin NEȚOIU

Eur. J. Entomol. 121: 425-434, 2024 | DOI: 10.14411/eje.2024.046

In the context of ongoing threats to forest ecosystems, this study investigates the temporal and spatial dynamics of Lymantria dispar defoliation intensity over a period of three years. We analysed the relationship between the insects' reproductive and feeding behaviours and forest stand characteristics, exploring the key factors that shape this behaviour. The results revealed a dynamic pattern, with a significant escalation of defoliation starting from the second year and peaking in the third. The analysis highlighted that, among several forest stand characteristics, woody species abundance and specific forest composition significantly influence population density and defoliation intensity. Sporadic outbreaks of the insects were associated with stand features, posing major challenges to forest health. These findings make a significant contribution to understanding the population dynamics of L. dispar and provide essential insights for forest managers in efficiently managing this defoliator. By highlighting the complex interactions between the insect and its environment, this study lays the groundwork for conservation and protection strategies for forest ecosystems.

Comparison of behavior and foraging ability between two congeneric species of large-bodied diving beetle (Coleoptera: Dytiscidae) larvae, a non-expanding species and a distribution-expanding speciesOriginal article

Taichi FUKUOKA, Shin-Ya OHBA, Masahide YUMA

Eur. J. Entomol. 122: 56-64, 2025 | DOI: 10.14411/eje.2025.006

Global warming has altered the distribution of several insect species, including those inhabiting aquatic environments and this range expansion may modify existing interspecific interactions by facilitating new encounters between species that were not originally sympatric. Global warming is highly likely to expand the distribution of Cybister tripunctatus lateralis (Coleoptera: Dytiscidae) in Japan, leading to interspecific competition for food resources among congeneric species. In particular, Cybister larvae share similar feeding habits, suggesting that interspecific competition is likely to occur, although this has not yet been verified. Therefore, this study aimed to compare the microhabitat use and foraging abilities of the larvae of two species - C. tripunctatus lateralis with an expanded distribution area and Cybister brevis, a non-expanding species of similar body size. We compared (1) behavior quantified by visual scan census, (2) time taken to reach food, and the number of prey animals consumed by each species in the laboratory experiments. The results indicated that the behavioral patterns of the larvae tended to involve mainly perch and rest on the plants. There were no clear differences between the two species, although there were variations among the instars. There was no difference in the number of prey animals consumed by the two species; however, it was evident that C. tripunctatus lateralis reached the food earlier than C. brevis. Therefore, it is suggested that the two species utilize a common underwater microhabitat, and that C. tripunctatus lateralis has a competitive advantage over C. brevis in terms of food resources. However, further experimental verification and continued expansion of C. tripunctatus lateralis distribution trends should be carefully monitored, as reproductive habitats in the field differ and competitive advantages may depend on water temperature.

Comparison of flight behaviour and flight morphology between perching Lycaena phlaeas and patrolling Zizeeria maha (Lepidoptera: Lycaenidae)Original article

Michio IMAFUKU

Eur. J. Entomol. 122: 73-78, 2025 | DOI: 10.14411/eje.2025.008

Perching (territorial) and patrolling are recognised as mate-locating tactics adopted by male butterflies. It is said that males adopting the former fly fast with high acceleration, whereas those adopting the latter fly at continuous and lower speeds. However, no previous studies have demonstrated these flight properties using quantitative data. In the present study, the flight properties of two lycaenid species, the perching L. phlaeas and the patrolling Z. maha, were investigated based on three-dimensional analysis. Males of L. phlaeas had higher flight velocities and higher relative flight time than those of Z. maha. Furthermore, the flight morphology that supports flight properties was examined. The perching L. phlaeas exhibited higher thorax-to-body mass ratios and greater wing loadings than patrolling Z. maha.

Diet of adult ladybird beetle host modifies the postdiapause development of the parasitoid Dinocampus coccinellae (Hymenoptera: Braconidae)Original article

John J. OBRYCKI, Catherine A. TAUBER, Maurice J. TAUBER

Eur. J. Entomol. 122: 111-117, 2025 | DOI: 10.14411/eje.2025.013

Our study showed that under natural conditions the rate and speed of postdiapause emergence by overwintering larvae of the endoparasitic wasp, Dinocampus coccinellae (Schrank) is enhanced when its ladybird beetle host Coleomegilla maculata (DeGeer) receives a nutritious (proteinaceous) diet during late winter and early spring. Living aphid prey provided during April and May yielded the fastest rates of D. coccinellae postdiapause development, followed by an artificial protein/carbohydrate diet and flowering (pollen-producing) heads of dandelion. D. coccinellae development was slowest when hosts received only sugar water or water alone. These results indicate that there is an interaction during late dormancy between host diet and subsequent parasitoid performance. From these studies we conclude that the initiation of feeding by C. maculata hosts, whether on prey or nutritious plant-based substances, during early spring may play an important role in the timing and success of postdiapause larval development and emergence by the parasitoid D. coccinellae. This interaction appears to be an adaptive feature that synchronizes the completion of the parasitoid's postdiapause development with the feeding and occurrence of potential ladybird beetle (C. maculata) hosts in spring. Thus, we conclude that at this point in their life cycles, the developmental success of both the host and the parasitoid are interdependent. It appears that the presence and utilization of aphid prey and/or a rich pollen source early in the spring season could have both positive and negative effects on the local population of ladybird beetle hosts.

Host plant specialization and bioturbation by the Amazonian cicada Orialella aerizulae (Hemiptera: Cicadidae)Original article

Erin M. RIVERA GROVES, Adrian FORSYTH, Edwin E. JURADO ROJAS

Eur. J. Entomol. 122: 164-172, 2025 | DOI: 10.14411/eje.2025.021

Adult cicadas in temperate zones are known for their synchronized, loud emergences after spending years underground as nymphs feeding on xylem sap. In contrast, the nymphal stage - where cicadas spend most of their lives - remains poorly understood, especially in the Neotropics. Spatial and host plant relationships between Amazonian cicada nymphs and host trees are virtually unknown, limiting our understanding of the ecological roles of cicadas in Amazonian forests. Here, we present the first detailed spatial ecology study of nymphs of Orialella aerizulae, a species that builds conspicuous turrets. Using systematic mapping and quantification of turrets around Tachigali spp. trees and random control trees, we provide the first quantitative evidence of a specific cicada-tree association by observing xylem-feeding on fine roots within these turrets. We examine the relationship between turret density, tree developmental stage and size, and document emergence and activity patterns over a 19-month field study in the Peruvian Amazon. Finally, we investigate the species' bioturbation impact and its potential relevance to tree growth.

Complementary roles of agricultural and natural habitats in supporting moth diversity in semi-arid landscapes of MoroccoOriginal article

Nidal FETNASSI, Stênio Italo Araújo FOERSTER, Erki ÕUNAP, Mohamed GHAMIZI, Toomas TAMMARU

Eur. J. Entomol. 122: 173-183, 2025 | DOI: 10.14411/eje.2025.022

Human activities, particularly those exacerbated by climate change, are major drivers of biodiversity change. While many human actions degrade biodiversity, some anthropogenic habitats can provide refuges for certain species, insects in particular. Research on the human impact on biodiversity remains uneven both geographically and taxonomically. In this study, nocturnal moth assemblages were compared across three habitat types (forest, riverbanks and olive groves) representing a gradient from natural to heavily human-altered environments in a semi-arid landscape of Morocco. Moths were systematically sampled across an altitudinal gradient ranging from 900 to 1600 m using automatic sugar-bait traps. We recorded 105 macroheteroceran species, most of which belonged to the families Noctuidae and Erebidae. The differences in moth assemblages among the studied habitats were statistically significant, with magnitudes comparable to those observed among the study sites. Altitude had a relatively weak influence on abundance and species richness. Olive groves exhibited the highest moth abundance and species richness, though they were dominated by common and widespread species. Forests supported a greater number of rare species, while riverbanks had lower abundance and species richness. In conclusion, while traditional agriculture can support species-rich insect communities in semi-arid landscapes, maintaining natural vegetation remains crucial, as forests, though less species-rich, still enhance overall moth diversity.

Localization of SNAP-29 and Syntaxin 6 in the brain of Bombyx moriOriginal article

Fumika TORYU, Yuto SAITOH, Kengo KANAMARU, Katsuhiko SAKAMOTO, Yuichi UNO, Tomohide UNO

Eur. J. Entomol. 122: 189-197, 2025 | DOI: 10.14411/eje.2025.024

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are a family of small conserved eukaryotic proteins that mediate fusion between organelles and the plasma membrane. Prior to fusion, complementary SNAREs, such as syntaxin, synaptosome-associated protein (SNAP), and synaptobrevin, assemble between membranes with the aid of accessory proteins that provide a scaffold to initiate SNARE zippering, pulling the membranes together, and mediating fusion. SNAP-29 and Syntaxin 6 from Bombyx mori were expressed in Escherichia coli and purified using affinity chromatography. We then produced antibodies against SNAP-29, and Syntaxin 6 of Bombyx mori in rabbits, which were used for immunohistochemistry. Immunohistochemistry results revealed that the expression of SNAP-29 was restricted to neurons in the pars intercerebralis (PI) and dorsolateral protocerebrum (DL) of the brain. The amount of SNAP-29 in the brain increases with hunger. Syntaxin 6 was restricted to neurons in the PI, the central complex (CX) and ventro-median protocerebrum (VP). SNAP-29 co-localized with SNAP-25 and Syntaxin 1A in the PI, and with Syntaxin 1A in the DL. Syntaxin 6 co-localized with SNAP-25 and Syntaxin 1A in the PI and with SNAP-25 in the CX. Bombyxin-immunopositive neurons of the brain occurred in SNAP-29 and Syntaxin 6-IRs. PTTH- and period-immunopositive neurons of the brain occurred in SNAP-29-IRs. Syntaxin 6 is present in EH secretory neurons of the brain.

The prospects of using retrotransposon iPBS molecular marker to characterise the genetic diversity of Chrysochraon dispar and Stethophyma grossum (Orthoptera: Acrididae)Original article

Rūta STARKA, Paula Marta MUCENIECE, Nikole KRASŅEVSKA, Andra MIĶELSONE, Gunita DEKSNE, Dace GRAUDA

Eur. J. Entomol. 122: 279-286, 2025 | DOI: 10.14411/eje.2025.032

Molecular markers have become indispensable tools in contemporary ecological research, offering insights into genetic diversity and structure. These parameters are pivotal for addressing fundamental questions in landscape ecology and planning effective species conservation. Grasshoppers have one of the largest genomes known. A significant portion of the grasshopper genome is composed of mobile genetic elements, with a particular abundance of retrotransposons. In this study, we utilised the iPBS (inter-primer binding sequence) PCR based fingerprinting marker system, as a novel approach based on retrotransposons for the study of Orthoptera. We evaluate the efficacy of the iPBS primers system in characterizing the genetic diversity of two large-genome grasshopper species, Stethophyma grossum and Chrysochraon dispar. Our findings demonstrate the potential of iPBS markers as a valuable tool for assessing the genetic diversity of orthopterans. This approach offers a promising avenue for future research in population genetics and conservation biology.

Temporal and spatial variation of Xylosandrus germanus (Coleoptera: Curculionidae: Scolytinae) captures in lowland forests: Positive effect of tree species diversity on the abundance of an invasive ambrosia beetleOriginal article

Marek DZURENKO, Ján KULFAN, Juraj GALKO, Peter ZACH

Eur. J. Entomol. 122: 302-307, 2025 | DOI: 10.14411/eje.2025.034

Invasive ambrosia beetles, such as the black stem borer (Xylosandrus germanus), pose serious ecological and economic threats to various natural, semi-natural and artificial ecosystems with suitable host plants. This study investigates the temporal and spatial variation in X. germanus abundance within lowland, mostly oak-dominated forests of the West Carpathians, focusing on the influence of tree species diversity, altitude, and forest stand age. Our findings reveal a strong positive correlation between tree diversity and X. germanus abundance, suggesting that diverse forests provide favourable conditions for beetle establishment. Altitude also exhibited a significant positive effect, likely due to increasing humidity and more suitable microclimatic conditions at higher elevations. In contrast, forest age had a small but significant negative effect, potentially due to reduced availability of stressed host trees in older stands. Beetle activity peaked in early to mid-June, in agreement with previous observations of phenology of this species in Central Europe. These findings contribute to our understanding of the ecological factors shaping X. germanus populations and provide valuable insights for forest management strategies aimed at mitigating the spread of invasive ambrosia beetles.

Nature conservation and insect decline in Central Europe: Loss of Lepidoptera in key protected sites is accompanied by substantial land cover changesOriginal article

Gwendoline PERCEL, Lukas CIZEK, Jiri BENES, Jan MIKLIN, Pavel VRBA, Pavel SEBEK

Eur. J. Entomol. 122: 308-322, 2025 | DOI: 10.14411/eje.2025.035

The insect biodiversity crisis affects diverse cultural landscapes as well as natural and semi-natural habitats. Accordingly, the effectiveness of protected areas in conserving insect communities needs to be evaluated. We employed photo-interpretation of aerial photographs from the past (1938-1947) and present (2014-2019) to analyse changes in natural habitats with diverse canopy cover in seven long-term protected areas (jointly called 'reserves') in the Czech Republic, Central Europe, and evaluated potential links between these changes and butterfly and moth (Lepidoptera) declines. We observed a marked decrease in habitat heterogeneity, largely due to the expansion of closed-canopy forests at the expense of semi-open habitats (e.g. forest steppes, open woodlands) and open grasslands. An analysis of faunistic records of 162 species of butterflies and 160 species of macro-moths before and after 2000 showed that, on average, the reserves have experienced losses of 26% of butterfly species and 19% of moth species. Trait-based analyses suggested that the losses were associated with particular life-history traits. Non-generalist butterflies with a short period of seasonal flight activity, and moths associated with grasslands and with non-feeding adults, had a greater probability of going missing (meaning potentially locally extinct) in the reserves. These findings suggest that conservation efforts should prioritise active management that aims to restore habitat heterogeneity in order to mitigate the ongoing trend of insect decline.

Book Review: Skinner G.J. & Jarman A.P. 2025: Ants.Book review

Pavel PECH

Eur. J. Entomol. 122: 330, 2025 | DOI: 10.14411/eje.2025.037

Skinner G.J. & Jarman A.P. 2025: Ants. Pelagic Publishing, London, 304 pp. ISBN 9781784273040. Price GBP 31.99.

Effect of buffer strips along small watercourses on farmland spiders (Araneae) and ground beetles (Carabidae)Original article

Johannes BURMEISTER, Sabine BIRNBECK, Bernd PANASSITI, Theo BLICK, Roswitha WALTER

Eur. J. Entomol. 122: 331-343, 2025 | DOI: 10.14411/eje.2025.038

Buffer strips along small waterways that are adjacent to arable land are important for improving water quality and are common measures in agri-environmental schemes. To assess their contribution to arthropod species richness (alpha and gamma diversity) and differences in assemblages (beta diversity) we used pitfall traps to catch arachnids and ground beetles at 40 fields in four regions across Bavaria, Germany, during two or three one-week sampling periods in summer. A permanent vegetated buffer strip was present on 25 of the study fields, 15 were cropped to the field border adjacent to the waterway. Trapping was conducted in the riparian field border, the buffer zone (with or without an established buffer strip), the field edge about 15 m distant to the field border and in the field centre in 80 m distance. Results indicated that alpha and gamma diversity were lowest in the field centre, and the riparian field border had the highest species richness of arachnids. Alpha diversity of ground beetles and spiders was not enhanced in fields with a buffer strip and the buffer strip did not have significantly higher species richness than cropped fields at the same field position. In contrast for ground beetles a higher species richness was observed in the unbuffered field border. An indicator species analysis showed that most of this effect was due to spillover of eurytopic arable species from the neighbouring field. For ground beetle assemblages buffered riparian field borders showed a higher dissimilarity to the other sampled field positions than riparian field borders without an adjacent buffer strip. We conclude that the establishment of buffer strips altered the faunal composition within the buffered riparian field border habitat in summer. We discuss ecological consequences, such as increased beta-diversity and changes in competition, which make buffer strips an important component of the preservation of biodiversity in agricultural landscapes.

Evolutionary rate of adaptive chromosomal inversions in Drosophila subobscura (Diptera: Drosophilidae) in response to global warmingOriginal article

Goran ZIVANOVIC, Concepció ARENAS, Francesc MESTRES

Eur. J. Entomol. 122: 359-369, 2025 | DOI: 10.14411/eje.2025.040

In the face of global warming, insects can employ various survival strategies. One possibility is that natural selection favors genetic combinations that are adaptive to this environmental situation. In some species, chromosomal inversions allow a particular combination of genes to be transmitted intact across generations, provided it is adaptive. Drosophila subobscura could therefore be considered a model species, given its rich chromosomal inversion polymorphism and its relationship with climate change. This polymorphism was studied in the Djerdap (Serbia) population in 2024, and its composition was found to have changed over time when the results were compared with those from 2001 and 2002. A significant decrease in 'cold' and an increase in 'warm' adapted inversions were observed when comparing 2001 and 2024. Also, the CTI (chromosomal thermal index) value for the whole karyotype in 2001 (0.162) was significantly different to that in 2024 (0.332) (adjusted p = 0.0084). Of the inversions studied, nine presented an observed frequency outside the interval expected assuming genetic drift. However, a change in agreement with global warming was detected in only five of these inversions, while the frequency of two 'non-thermal' adapted inversions also increased. Finally, an evolutionary rate was calculated by dividing the difference in frequency between 2024 and 2001 by the number of years that had elapsed. The values obtained for the 'cold', 'warm' and 'non-thermal' adapted were -0.0030126, 0.0030148 and -2.609 × 10-6, respectively. These values are lower than those previously reported for the Apatin (Serbia) population.

Evaluation of the efficacy of novel, meat-free and easily sterilisable artificial diet for mass rearing of Lucilia sericata (Diptera: Calliphoridae) larvae for medical applicationsOriginal article

Izabela KUBASIK, Alicja MICHALCZUK, Jaspreet Kaur JANDOO, Tomasz SKALSKI, Artur GÓRA, Katarzyna PAPAJ

Eur. J. Entomol. 122: 392-403, 2025 | DOI: 10.14411/eje.2025.044

Medically significant Lucilia sericata larvae lack a standardised, reproducible, animal tissue-free, and sterilisable diet for rearing. In this study, we developed and evaluated a diet made from dried milk, protein powder, cholesterol, amino acids, and vitamins with a defined macronutrient composition. We demonstrated that this formulation supports larval development comparable to that of control liver diet. This diet composition was also tested with a deficiency in each ingredient to determine their role and influence on larval development. Specifically, the effects of these diets on the following traits of the fly were measured: third instar larvae length and weight, pupal weight, pupation percentage, eclosion percentage, adult longevity, and egg-laying capacity across two generations. Based on performed studies, we demonstrated that Lucilia sericata did not successfully develop on a diet lacking vitamins. Moreover, reduced third instar larval survivorship was observed in diets deficient in protein and cholesterol, whereas higher eclosion failure occurred in diets lacking milk, protein, and Ω-acids. These results indicate that each ingredient is important in the larval development. Overall, larvae reared on liver-based diets showed similar characteristics to those reared on artificial diets. Furthermore, subsequent generations of Lucilia sericata reared on this diet exhibited normal development and reproductive capacity, and their eggs produced viable offspring. This represents a potentially novel formulation, with sterilisable and readily available ingredients, and a meat-free composition that can be easily produced and used for medical applications.

Direct tests of haplodiploid inheritance in Thrips tabaci (Thysanoptera: Thripidae) using parent-offspring SSR-GBSOriginal article

Tatsumi KUDO, Po-Wei HSU, Shigeto DOBATA

Eur. J. Entomol. 122: 404-412, 2025 | DOI: 10.14411/eje.2025.045

Haplodiploidy is a sex determination system in which males are haploid and females are diploid. In the typical haplodiploid system, females inherit half of their genome from each parent, whereas males inherit a haploid genome exclusively from their mother. However, several exceptions to this pattern have recently been reported in some insects and spider mites, underscoring the need for rigorous genetic analyses of inheritance patterns in other haplodiploid species. Thrips (order Thysanoptera) are a major clade that exhibits haplodiploidy. Here, we investigated inheritance in the onion thrips, Thrips tabaci, by comparing parent-offspring genotypes using an amplicon-based microsatellite genotyping-by-sequencing method (Short Sequence Repeats-Genotyping by Sequencing, SSR-GBS). We successfully genotyped eight loci across eight families from the sexual lineage and additionally analyzed five families from the thelytokous lineage, including both diploid and triploid strains. In the sexual lineage, segregation conformed to arrhenotoky: F1 females inherited one allele from each parent, and F1 males carried a single maternal allele. In the thelytokous lineage, offspring inherited only alleles present in the mother. Compared with fragment-length genotyping, SSR-GBS increased the mean number of alleles detected per locus by 28% and reduced the rate of size homoplasy (alleles of the same size but different sequences), yielding clearer separation of the sexual and thelytokous lineages. These findings advance our understanding of the evolution of reproductive systems in this major haplodiploid clade and demonstrate the utility of SSR-GBS for high-resolution SSR genotyping.

Efficacy of semiochemical-baited traps for detection of Scolytinae species (Coleoptera: Curculionidae) in the Russian Far EastOriginal article

Jon D. SWEENEY, Peter SILK, Vasily GREBENNIKOV, Michail MANDELSHTAM

Eur. J. Entomol. 113: 84-97, 2016 | DOI: 10.14411/eje.2016.010

Traps baited with plant volatiles and/or bark beetle pheromones have been used to survey for exotic and potentially invasive bark and wood-boring beetles in North America since the mid-1990s. Recent discoveries of sex and aggregation pheromones in the Cerambycidae offer means of improving detection rates of longhorn beetles, but little is known of their effects on detection of bark and ambrosia beetles in the subfamily Scolytinae. Our objectives were to determine the efficacy of host volatile trap lures for survey and detection of Scolytinae species and whether that efficacy was affected by the addition of longhorn beetle pheromones. More than 12,000 specimens and 36 species of Scolytinae were collected in two field trapping bioassays conducted in the Russian Far East in 2009 and 2010. The lure combination of spruce blend (a blend of racemic α-pinene, (-) β-pinene, (+)-3-carene, (+)-limonene, and α-terpinolene) and ethanol significantly increased detection rates and mean catches of Hylastes brunneus Erichson, Hylastes obscurus Chapuis, Ips typographus (L.), and Dryocoetes striatus Eggers compared with unbaited traps. The addition of the longhorn beetle pheromones, E-fuscumol, or E-fuscumol acetate, to traps baited with spruce blend and ethanol, slightly reduced mean catches of D. striatus but otherwise did not affect catch of any Scolytine species. Baiting traps with ethanol significantly increased mean catches of Anisandrus apicalis (Blandford), Anisandrus dispar (Fabr.), Anisandrus maiche (Kurenzov), Xyleborinus attenuatus (Blandford), Xyleborinus saxesenii (Ratzeburg), Xylosandrus germanus (Blandford), Scolytoplatypus tycon Blandford, and Trypodendron lineatum (Olivier). By themselves, the longhorn beetle pheromones, racemic hydroxyhexan-2-one and racemic hydroxyoctan-2-one, were not attractive to any Scolytine species. However, when added to ethanol-baited traps, hydroxyhexan-2-one lures significantly increased mean catch of S. tycon, hydroxyoctan-2-one lures significantly reduced mean catches of A. maiche and X. attenuatus, and lures of either hydroxyketone significantly reduced mean catch of T. lineatum. The lure treatments that detected the greatest number of species per sampling effort were spruce blend plus ethanol in 2009 (16 Scolytinae species and 13 species of Cerambycidae combined in an eight-trap sample) and hydroxyhexan-2-one plus ethanol in 2010 (20 Scolytinae species and 7 species of Cerambycidae combined in an eight-trap sample). Species accumulation curves did not reach an asymptote for any lure treatment, indicating that many species would go undetected in samples of 8-9 traps per site.

Nesting ecology of Polistes gallicus (Hymenoptera: Vespidae) in South-Western SpainOriginal article

José Luis PÉREZ-BOTE, Carlos MORA-RUBIO, Josefa LÓPEZ MARTÍNEZ, Tomás RODRÍGUEZ RIAÑO

Eur. J. Entomol. 117: 243-251, 2020 | DOI: 10.14411/eje.2020.026

Among the numerous factors that contribute to the success of social wasps, colony productivity is the most important and depends on ecological and environmental factors, such as the nest site. Consequently, nest-site choice should be determined by nest-site characteristics. The objective of this study was to determine on which species of plants Polistes gallicus wasps build their nests and identify the possible preferred features of plants used during nest-site selection by the foundress. From February to October 2017-2019 we recorded details of the nests in natural areas in south-western Spain (at 38° latitude). Nests of P. gallicus were recorded on 49 species of plants belonging to 23 families, with Scirpoides holoschoenus, Epilobium hirsutum and Foeniculum vulgare the most common. Significantly more wasps built their nests on herbaceous than on shrub and arboreal plants, and on "green" than "brown-grey" plants. Most of the nests were 21 to 189 cm above the ground, with a nest azimuth of about 102°. Nests were located at a mean distance of 43.51 ± 123.79 m from the nearest source of water. The length of the nesting season in the area studied was between 30 and 33 weeks, and more colonies were founded by a single foundress than several foundresses. Furthermore, a greater percentage of the single foundress colonies failed than of the multiple-foundress colonies.

Carabid beetles (Coleoptera: Carabidae) in several types of forests on Hokkaido, Japan, with implications for forest management practices and beetle preservationOriginal article

Jun KAIZUKA, Tamaki YAMAGUCHI, Mitsuhiro IWASA

Eur. 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.

The associations between ground beetle (Coleoptera: Carabidae) communities and environmental condition in floodplain forests in the Pannonian BasinOriginal article

Juraj LITAVSKÝ, Oto MAJZLAN, Slavomír STA©IOV, Marek SVITOK, Peter FEDOR

Eur. 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.

Assemblage of entomopathogenic fungi infesting immature stages of Noctuidae (Lepidoptera): High diversity but low effect on host populationsShort Communication

Robin GIELEN, Tiit TEDER, Kadri PÕLDMAA, Toomas TAMMARU

Eur. J. Entomol. 120: 182-186, 2023 | DOI: 10.14411/eje.2023.023

Populations of herbivorous insects are considered to be primarily regulated by natural enemies. However, little is known about the ecological role of entomopathogenic fungi. There is very little data on the diversity and prevalence of fungal pathogens in natural insect populations. In this study, the percentage mortality attributable to fungal pathogens for the immature stages of three noctuid moths feeding inside the stems of the herbaceous plant, Typha latifolia, were determined. The average percentage mortality caused by fungal pathogens was around 8%, with the value never exceeding 20% at any of the studied sites. As many as ten species of fungi were identified in the 52 infected larvae/pupae collected, this high diversity is consistent with the results of comparable studies. The prevalence of fungal infections did not correlate with host population density or performance of the host insects. This study contributes to the emerging generalisation that populations of insects commonly harbour diverse assemblages of pathogenic fungi, but with low overall prevalence. A significant contribution of these antagonists to regulating insect populations is unlikely.

Environmental variables associated with insect richness and nestedness on small islands off the coast of northeastern AlgeriaOriginal article

Lyes AISSAT

Eur. J. Entomol. 120: 244-253, 2023 | DOI: 10.14411/eje.2023.027

This study investigated the association of environmental factors with insect richness and nested patterns in the distribution of species of insects on small islands (northeastern Algeria). Insect species on eleven (11) islands were sampled using pitfall traps, sweep netting and a Japanese umbrella. To explain patterns in insect diversity on small islands, a generalized linear model (GLM) was used to determine the association of the overall richness and that of the dominant orders of insects with environmental variables (altitude, surface area, isolation, plant richness and number of habitats). To determine the nestedness pattern on these islands, the online interface NeD was used to measure total matrix nestedness. Of the variables measured, only plant richness was associated with variations in the overall species richness and that of the five dominant orders. The overall number of insects and that of the five dominant insect orders were significantly nested in all null models except the very restrictive FF model. Plant richness accounted for the nested structure of the overall number of insects and that of the five dominant orders (Coleoptera, Hymenoptera, Hemiptera, Diptera and Lepidoptera). Surface area was also important in the nested structure of overall number of insects and that of the order Lepidoptera. The nestedness of the overall number of insects and that of the five dominant orders of insects, however, did not result from passive sampling and selective colonization. The most effective way of conserving overall number of insects and that of the five dominant orders of insects on the Algerian islands studied is to protect their plant richness and to maximize the overall number of species and that of Lepidoptera on these islands, conservation should concentrate on the largest islands.

Stages in the degeneration of flight ability and their interspecific comparisons in the genus Synuchus (Coleoptera: Carabidae) in JapanOriginal article

Takashi SHIMIZU, Kôhei KUBOTA, Hiroshi IKEDA

Eur. J. Entomol. 121: 7-18, 2024 | DOI: 10.14411/eje.2024.002

The degeneration in flight ability in beetles has rarely been studied in detail with regard to the polymorphism of flight traits within species. However, intraspecific diversity in flight traits means that the flight ability of species is in the process of degenerating, which could provide important insights into how flight ability in beetles degenerates. In this study, the flight muscle and hind wings of the genus Synuchus in Japan were studied, which revealed the morphological status of flight traits in 21 species of Synuchus. Several species in this genus were found to show intraspecific polymorphisms in the states of the flight muscle and hind wings, and in particular, the very high diversity of different types of hind wings. These results indicate that this genus contains a mixture of species at various stages in the degeneration of the ability to fly.

Effect of fungicide sprays on spiders in vineyardsOriginal article

Jo Marie REIFF, Christoph HOFFMANN, Martin H. ENTLING

Eur. J. Entomol. 121: 19-28, 2024 | DOI: 10.14411/eje.2024.003

Spiders are the most abundant naturally occurring predators in vineyards and play a crucial role in natural pest control. However, vineyards are frequently sprayed with fungicides, which can harm spider communities. Fungus-resistant grape varieties can drastically reduce this fungicide input. The spiders on grape vines that were sprayed with a variable number of fungicide applications in 32 vineyards in different landscapes in Southwestern Germany were recorded. Vineyards received between 0 and 14 fungicidal sprays of varying toxicity (cumulated hazard quotients for honeybee up to 6). The majority of spiders benefited from a reduction in the number fungicide sprays, particularly Dictynidae, Philodromidae, Theridiidae and Thomisidae. Overall, space web weavers, orb web weavers and ambush hunters were most strongly affected by the frequency and toxicity of fungicide applications. The response of spiders to the landscape were highly variable and included both positive and negative effects of the percentage cover of woodland. In conclusion, reducing the cumulative hazard of fungicides by reducing the number of fungicide applications is a key element in fostering spiders in vineyards.

DNA metabarcoding of gut microbiota reveals considerable taxonomic differences among wild individuals of the dung beetle Trypocopris pyrenaeus (Coleoptera: Geotrupidae)Original article

Gianluca NATTA, Samuele VOYRON, Erica LUMINI, Alex LAINI, Alfredo SANTOVITO, Angela ROGGERO, Claudia PALESTRINI, Antonio ROLANDO

Eur. J. Entomol. 121: 40-53, 2024 | DOI: 10.14411/eje.2024.007

The gut microbiota of dung beetles comprises bacteria, archaea, and fungi. Most studies have only considered the bacterial element and focused on differences between species reared in the lab. This study considered microorganisms from the gut of Trypocopris pyrenaeus and concentrated on differences among wild individuals of an alpine Italian population. We revealed remarkable interindividual variation in the taxonomic composition of microbiota. Core taxa were few, while individuals harboured many exclusive taxa. Therefore, considering only a few individuals to describe the microbiota of a species is not sufficient. The study also revealed that the nMDS ordination of individuals based on prokaryotes was different from that based on fungi, meaning that both groups should be considered in microbiota analyses and that one microbic group cannot be considered a surrogate of the other. We identified many functions potentially provided by the microbiota and found the taxonomic richness of prokaryotes to be positively correlated with their functional richness. The analysis of the functions potentially provided by these microorganisms confirmed that the gut microbiota, in addition to being essential for the health of their host, may also contribute to the effective functioning of the ecosystems of which dung beetles are part.

Functional analysis of two SfHsp90 genes in response to high temperature and insecticide stress in Spodoptera frugiperda (Lepidoptera: Noctuidae)Original article

Hong-Yun RUAN, Lv ZHOU, Lei YANG, Jian-Yu MENG, Chang-Yu ZHANG

Eur. J. Entomol. 121: 54-63, 2024 | DOI: 10.14411/eje.2024.008

Spodoptera frugiperda, a worldwide pest, can feed on 353 crops species, including corn, rice, and sorghum. It is highly adaptable to various environments. Heat shock protein 90 kDa (Hsp90) plays a crucial role in the environmental adaptation of insects. To explore the role of SfHsp90 genes coding for Hsp90 proteins in the high temperature and insecticides stress resistance of Spodoptera frugiperda, we identified the complete complementary DNA sequences of two SfHsp90s. Both of them were expressed at different developmental stages and tissues in S. frugiperda. The expression levels of the SfHsp90s were significantly upregulated when exposed to durations of extreme temperature (45°C) and lethal concentrations of emamectin benzoate (LC10 and LC20). The viability of S. frugiperda under 45°C and emamectin benzoate stresses was examined. The mortality rate of S. frugiperda was significantly increased when subjected to 45°C and emamectin benzoate after knockdown of SfHsp90s by RNAi. These results suggest that SfHsp90s are essential for the resistance of S. frugiperda to high temperature and emamectin benzoate stresses.

Using citizen science data to compare flight phenology of two oligolectic bees (Hymenoptera: Andrenidae) with the flowering of their host plantsOriginal article

Per MILBERG, Anna PALM

Eur. J. Entomol. 121: 67-72, 2024 | DOI: 10.14411/eje.2024.010

Understanding the relationship between solitary bee flight and flowering phenology is globally relevant for environmental management and habitat restoration. Using Swedish citizen science data over an 11-year period, the flight behaviours of two oligolectic solitary bees (Andrena hattorfiana and Andrena marginata) were compared to the flowering phenology of their hosts (Knautia arvensis and Succisa pratensis) in southern Sweden. There were 2,327 and 4,566 records of flight and flowering, respectively. While associative studies cannot resolve the degree of oligolecty, a strong temporal association of Andrena hattorfiana with Knautia arvensis and Andrena marginata with Succisa pratensis was indicated. Three conclusions emerged when comparing annual data: first, the flight period of both bee species studied overlapped with the flowering period of their corresponding host plants. Second, earlier flowering of Knautia arvensis corresponded with the earlier flight of Andrena hattorfiana. Third, the flight period duration was unaffected by the flowering period duration. For Andrena hattorfiana/Knautia arvensis, climate change may shift the start of flight and flowering periods to earlier dates in the year. A similar response would be expected for Andrena marginata/Knautia arvensis, but not for Andrena marginata/Succisa pratensis where there instead might be an increasing mismatch between the flight and flowering periods.

Review of the cuticular lipids of spiders (Araneae)Review

Marek CHAJDUK, Cezary TKACZUK, Marek GO£ÊBIOWSKI

Eur. J. Entomol. 121: 73-82, 2024 | DOI: 10.14411/eje.2024.011

Cuticular lipids are essential for the functioning of all arthropods. They maintain water balance, are involved in intraspecific and interspecific chemical communication and prevent fungal and bacterial infections. Although, the insect's lipid layer is relatively well known, that of spiders is considerably less well known. Only a few species are studied in terms of the identification and composition of cuticular lipids. The results obtained so far are discussed in this article. Spiders are subjected to various forms of extraction and in the majority of cases the subsequent analysis using GC-MS identified hydrocarbons, carboxylic acids, esters, alcohols, aldehydes, ketones, methyl ethers and cholesterol. Among these lipids there are semiochemicals, mainly pheromones and kin recognition cues. Despite the few publications on spider cuticular lipids, this subject is significant in terms of searching for antimicrobial substances such as potential bio fungicides and medicines.

Evidence of a South American origin for the Drosophila repleta group (Diptera: Drosophilidae)Original article

Andrea E. ACURIO

Eur. J. Entomol. 121: 124-133, 2024 | DOI: 10.14411/eje.2024.015

The Drosophila repleta group is one of the most widely used model systems for studying adaptation and speciation. Traditionally, five subgroups are recognized within the repleta group: fasciola, hydei, mercatorum, repleta and mulleri. A sixth subgroup, inca, was the last to be defined. The inca species subgroup includes three species: Drosophila inca, Drosophila huancavilcae and Drosophila yangana, all of which are endemic to Ecuador and Peru. Previous molecular phylogenetic studies have been inconclusive regarding the geographic location, time and mode of diversification of lineages within the repleta group. By applying a phylogenetic and biogeographical analysis of 54 taxa belonging to the repleta, nannoptera, atalaia and virilis groups, the aim of this study was to: (1) determine the relationships between the inca subgroup and the other five subgroups within the repleta group, (2) improve the unresolved branching and low supports of the early divergent lineages in the repleta group phylogeny and (3) estimate the geographic and temporal context of the early divergence within the repleta group. Based on these findings, it is proposed that the Drosophila repleta group first diversified during the mid-late Miocene, most likely following the uplift of the Northwestern Andes.

Kevinilla, a new velvet ant genus in the Sphaeropthalminae (Hymenoptera: Mutillidae)Original article

Pedro R. BARTHOLOMAY, Roberto A. CAMBRA, Carlos W. RAMOS, Estibali WILKIE, Yostin J. AÑINO

Eur. J. Entomol. 121: 182-196, 2024 | DOI: 10.14411/eje.2024.019

The new genus Kevinilla Bartholomay & Cambra includes the following four Neotropical species: Kevinilla ludovica (Cameron, 1895) comb. n. (the type species), K. bicarinata (Cambra & Quintero, 2008) comb. n., K. bimaculata (Cambra & Quintero, 2008) comb. n., and K. hansoni (Cambra & Quintero, 2008) comb. n., all transferred from Pseudomethoca. A neighbour joining tree clustered IST1 sequences of Kevinilla in a subclade of the main clade, which includes species of Pseudomethoca and Dasymutilla. Therefore, here Kevinilla is considered to be a member of the subfamily Sphaeropthalminae, tribe Pseudomethocini. A key for both sexes of the known species of Kevinilla is given, as well as an account of seasonal flight activity of males recorded over six years using Malaise traps on Barro Colorado Island, Panama.

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