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Results 241 to 270 of 1606:

The effects of mating on the reproductive fitness of Microplitis rufiventris (Hymenoptera: Braconidae)Original article

Esmat M. HEGAZI, Christophe BRESSAC, Wedad KHAFAGI

Eur. J. Entomol. 117: 266-272, 2020 | DOI: 10.14411/eje.2020.030

The synovigenic braconid parasitoid, Microplitis rufiventris Kokujev is a promising wasp for use in augmentative releases against young larvae of some noctuid pests, including Spodoptera littoralis (Boisduval), in Egypt. It also has the potential to control the invasive noctuid Spodoptera frugiperda (J.E. Smith) in Africa. M. rufiventris is monandrous in the wild but is polyandrous under some laboratory rearing conditions. S. littoralis larvae were used as hosts to gain an understanding of the influence of mating on wasp-fitness. Newly emerged females (0-3 h old) of M. rufiventris were assigned to one of six mating schedules: Virgin females mated once (on day 1, 3 or 5) or 3 times during their life or provided daily with fresh virgin males. These mating schedules affected fecundity, reproductive longevity and sex ratio of the progeny. The life time fecundity of wasps mated on day 5 or mated three times was higher than that of other females, but their reproductive longevity was significantly shorter. In most cases, offspring production per female per day decreased with age. Mated M. rufiventris females produced significantly more progeny than virgin females. The progeny of virgin females consisted only of males, females that mated once had strongly male-biased sex ratios, whereas multi-mated females had a more female-biased sex ratio. More sperm was stored in the spermatheca than the number of daughters produced in any of the mating schedules. Age at first mating affected the lifetime fecundity. At death, the ovaries of mated wasps contained significantly more mature eggs than those of virgin wasps, indicating that mating increased egg production. This information can help enhance the efficiency of parasitoid mass-rearing and their use as biocontrol agents of noctuid pests.

Dragonflies and damselflies (Odonata) in urban ecosystems: A reviewReview

Giovanna VILLALOBOS-JIMÉNEZ, Alison M. DUNN, Christopher HASSALL

Eur. J. Entomol. 113: 217-232, 2016 | DOI: 10.14411/eje.2016.027

The expansion of urban areas is one of the most significant anthropogenic impacts on the natural landscape. Due to their sensitivity to stressors in both aquatic and terrestrial habitats, dragonflies and damselflies (the Odonata) may provide insights into the effects of urbanisation on biodiversity. However, while knowledge about the impacts of urbanisation on odonates is growing, there has not been a comprehensive review of this body of literature until now. This is the first systematic literature review conducted to evaluate both the quantity and topics of research conducted on odonates in urban ecosystems. From this research, 79 peer-reviewed papers were identified, the vast majority (89.87%) of which related to studies of changing patterns of biodiversity in urban odonate communities. From the papers regarding biodiversity changes, 31 were performed in an urban-rural gradient and 21 of these reported lower diversity towards built up city cores. Twelve of the cases of biodiversity loss were directly related to the concentrations of pollutants in the water. Other studies found higher concentrations of pollutants in odonates from built-up catchments and suggested that odonates such as Aeshna juncea and Platycnemis pennipes may be candidate indicators for particular contaminants. We conclude by identifying current research needs, which include the need for more studies regarding behavioural ecology and life-history traits in response to urbanisation, and a need to investigate the mechanisms behind diversity trends beyond pollution.

Phenotypic pattern over centric fusion clinal variation in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)Original article

Pablo C. COLOMBO, María I. REMIS

Eur. J. Entomol. 115: 303-311, 2018 | DOI: 10.14411/eje.2018.029

The water-hyacinth grasshopper, Cornops aquaticum, occurs in freshwater environments in the New World between latitudes 23°N and 35°S. At the southernmost margin of this distribution the populations are polymorphic for three centric fusions (Robertsonian translocations). The frequencies of these chromosome rearrangements increase southwards and the recombination in structural homozygotes and heterozygotes diminishes both along the middle and lower courses of the Paraná River. In the present paper we report a similar cline along the southward flowing Uruguay River. In addition, we report the morphological effects of two of these centric fusion polymorphisms, namely the fusions between chromosomes 2 and 5 of the standard complement (fusion 2/5) and chromosomes 3 and 4 (fusion 3/4) and extend this study to the Uruguay River. There is a strong inverse correlation of fusion frequency with temperature, which indicates that these polymorphisms may be related to increased tolerance of colder climates in this originally tropical species, or some other correlated variable. This study is a further example of chromosomal clines correlated with latitude and is one of a few examples of chromosome polymorphisms associated with phenotypic effects. Finally, it indicates ways of using this species for controlling pests.

Does Hartigiola annulipes (Diptera: Cecidomyiidae) distribute its galls randomly?Original article

Sebastian PILICHOWSKI, Marian J. GIERTYCH

Eur. J. Entomol. 115: 504-511, 2018 | DOI: 10.14411/eje.2018.050

It is expected that environmental conditions impact the distribution of galls on host plants. Moreover, insects may induce their galls randomly or choose certain parts of a host to induce such growths. This study aimed to determine whether or not the gall midge, Hartigiola annulipes (Diptera: Cecidomyiidae), which induces galls on leaves of the European beech (Fagus sylvatica), prefers leaves facing a particular cardinal direction. In addition, we wanted to ascertain whether the galls are evenly spread across three leaf zones: proximal, median and distal, distinguished by dividing leaf area along the midrib. The results show that H. annulipes chose leaves facing various directions in different studied locations, and leaf choice is not restricted to the specific leaf area, a parameter that accurately reflects the light conditions of leaf growth. Moreover, the medial leaf zone was preferred, while the distal zone was avoided. The choice of the leaf zone modified the distance between the mid-rib and a gall. Gall distribution in the crown of trees is probably random, while at the leaf level, it is determined by leaf morphology.

Body weight loss of black soldier fly Hermetia illucens (Diptera: Stratiomyidae) during development in non-feeding stages: Implications for egg clutch parametersOriginal article

Bogdan GEORGESCU, Dãnuț STRUȚI, Tudor PÃPUC, Daniela LADOȘI, Anca BOARU

Eur. J. Entomol. 117: 216-225, 2020 | DOI: 10.14411/eje.2020.023

The developmental stages of the black soldier fly, Hermetia illucens, are widely studied because there are several ways in which this species can be utilized. In this context, the aim of the current study is to determine the loss of weight of larvae of different weights between the prepupal and reproductive adult stages and their effect on the egg clutch quality parameters. The Hermetia illucens prepupae were categorized in 3 body weight classes. The weight loss was evaluated by weighing individuals in the prepupal, pupal and adult stages. The weight and length of the individuals were positively correlated in the pupal stage and adult females. There were significant losses of weight (P = 0.000) in the prepupal, pupal and adult stages in all three weight classes. In each weight class the relationship between weights was significant (P = 0.000) for all development stages. The results clearly indicate that the largest larvae of Hermetia illucens produced the adults with the best clutch quality parameters and the existence of significant positive correlations between body weight and both weight loss and the egg clutch quality parameters.

Asymmetry in host plant preferences of two ecotypes of Boloria eunomia (Lepidoptera: Nymphalidae)Original article

Przemys³aw KLIMCZUK, Marcin SIELEZNIEW

Eur. J. Entomol. 117: 380-392, 2020 | DOI: 10.14411/eje.2020.042

The diversity and evolution of host-plant relationships of butterflies has been the subject of much research. In this context, an interesting species is the bog fritillary Boloria eunomia. Across its boreo-montane distribution there are several ecotypes of this butterfly (sometimes distinguished as subspecies), which inhabit distinctly different habitats. However, little is known about the relationships between these forms in terms of host-plant use. We compared larval preferences of two ecotypes in north-eastern Poland, a unique region that is inhabited by different evolutionary lineages of B. eunomia. Larvae of the meadow ecotype reared in captivity were able to grow and develop exclusively on Persicaria bistorta, i.e., their 'native' host plant. In contrast, larvae originating from populations inhabiting raised bogs generally showed poorer survival, though they accepted both Ericaceae species growing in their biotope and P. bistorta, a plant that does not occur in their biotope. They did not show clear food preferences, but mortality was lowest when they were fed Vaccinium uliginosum. This is puzzling as field observations indicate that Vaccinium oxycoccus is the main host plant in the area studied. However, our findings are consistent with the results of phylogeographical studies indicating that meadows were the ancestral habitats of B. eunomia and some populations adapted later to different biotopes. The poor survival of larvae of the bog ecotype recorded in the present study may indicate that this form is at least locally potentially more vulnerable than the other ecotype.

Behaviour and metabolism during tonic immobility (death-feigning) in Eucryptorrhynchus scrobiculatus and E. brandti (Coleoptera: Curculionidae)Original article

Huijuan LI, Junbao WEN

Eur. J. Entomol. 118: 322-329, 2021 | DOI: 10.14411/eje.2021.033

The antipredator behaviour, tonic immobility (TI) is a valuable defence that enables insects to increase their chance of survival and is a trade-off between fleeing and protection. How the TI strategies of insects respond to environmental factors, however, remains a largely understudied subject. In this paper the effect of four factors (mechanical stimulation, light, sound and temperature) and metabolic responses were used to evaluate TI behavioural and physiological adaptions in Eucryptorrhynchus scrobiculatus (ESCR) and Eucryptorrhynchus brandti (EBRA). In the behavioural experiment, the metaventrite, which is the stimulus-sensing region in ESCR and EBRA, was subjected to mechanical stimulation. Light lengthened the TI duration in ESCR males, while sound had the opposite effect in ESCR and EBRA. The effect of temperature on the duration of TI was variable: in ESCR, the duration was shorter at low (15°C) and high (32°C) temperatures, but in EBRA, it was longer at the low (15°C) temperature. In the metabolism experiment, ESCR and EBRA metabolic rates (MR), was significantly dependent on whether they were in a state of TI or not. The TIMR declined to 76.90% in ESCR and 71.40% in EBRA. These results indicate that TI in ESCR and EBRA differed under different external conditions and contributes to the understanding of the physiological regulation of ecological traits of insect TI.

The pheromone verbenone and its function in Dendroctonus armandi (Coleoptera: Curculionidae: Scolytinae)Original article

Mingzhen ZHAO, Lulu DAI, Yaya SUN, Danyang FU, Hui CHEN

Eur. J. Entomol. 114: 53-60, 2017 | DOI: 10.14411/eje.2017.008

The Chinese white pine beetle, Dendroctonus armandi Tsai and Li is a native species of bark beetle and one of the most destructive in much of western China. Little is known about the characterization of the pheromones trans-verbenol and verbenone, and their functions in D. armandi are unknown. Electroantennogram tests (EAG) and olfactory assays (Y-tube assays) in the laboratory revealed that (1) trans-verbenol may be an anti-aggregation pheromone for male and an aggregation pheromone for female D. armandi and (2) female beetles are more attracted to controls (hexane) than low concentrations of verbenone and male beetles more attracted to controls than high concentrations of verbenone. Field trials indicated that the addition of verbenone to bait used to trap D. armandi remarkably decreased the efficiency of field trapping. These results indicate that verbenone is an anti-aggregation pheromone for male D. armandi. This research provides evidence of the role of verbenone among the different types of pheromones. The pheromone verbenone clearly could be used to protect healthy Chinese white pines.

Oviposition preference maximizes larval survival in the grass-feeding butterfly Melanitis leda (Lepidoptera: Nymphalidae)Original article

Freerk MOLLEMAN, Sridhar HALALI, Ullasa KODANDARAMAIAH

Eur. 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.

Tribal affiliation of endemic Macaronesian bush-crickets similar to Tettigonia (Orthoptera: Tettigoniidae) based on their karyology and taxonomyOriginal article

El¿bieta WARCHA£OWSKA-¦LIWA, Howon RHEE, Klaus-Gerhard HELLER, Beata GRZYWACZ

Eur. J. Entomol. 117: 157-163, 2020 | DOI: 10.14411/eje.2020.018

Two endemic genera of large tettigoniids are found in the Canary Islands and Madeira, which are morphologically similar to the genus Tettigonia. In this study, the karyotypes of representatives of the Glyphonotini genera Calliphona and Psalmatophanes are described for the first time. Comparison of their chromosomes with that of members of Tettigoniini genus Tettigonia revealed that all of the species studied have the same karyotype (2n = 29 with sex determination system X0 in the male), which differs from the ancestral tettigoniid karyotype by one Robertsonian translocation. These results support not only the morphological and molecular genetic evidence but also the hypothesis of a close relationship between Tettigonia and the endemics Calliphona and Psalmatophanes. Cytogenetic data of Glyphonotini strongly indicate that the taxonomy of thes lineage needs to be re-evaluated in which evidence from multiple sources could help resolve the taxonomic problems.

Harmonia axyridis (Coleoptera: Coccinellidae): Smelling the rat in native ladybird declinesPoint of view

John J. SLOGGETT

Eur. J. Entomol. 114: 455-461, 2017 | DOI: 10.14411/eje.2017.058

In the last two decades a huge amount of research has focused on the invasive harlequin ladybird, Harmonia axyridis, particularly on potential or actual deleterious effects that have arisen after it has colonised new regions. A focus of this work has been real or anticipated declines in native ladybird abundance since the introduction of H. axyridis, for which it is deemed responsible. Scientists have generally painted a very bleak picture of the effects of H. axyridis on native species: in this paper I argue that the picture painted is often too bleak. I use the case of the 2-spot ladybird, Adalia bipunctata, the species most often invoked as threatened by H. axyridis, to illustrate my point. While there is little question that H. axyridis has led to a decline in A. bipunctata populations in Europe, it seems likely that prior to the invasive ladybird's arrival A. bipunctata occurred in artificially high numbers in the urban environments in which it was typically studied. Pollution in towns and cities led to enhanced numbers of prey aphids on plants there which initially favoured A. bipunctata, and later H. axyridis. Thus one species, A. bipunctata, that has benefitted from an association with humans has been replaced by another, H. axyridis, just as brown rats replaced black rats in Europe and North America. Viewed with a longer perspective, A. bipunctata has more likely declined back to pre-industrial levels: the artificially high level from which it has declined recently was not a 'natural' one, and thus its decline from this level does not imply that it is now threatened or endangered. More broadly, we need a wider perspective, encompassing other ladybirds, longer timeframes and better comparisons with other (non-ladybird) invasive species to more clearly assess whether H. axyridis really poses as much of a threat as is often proposed.

Assemblages of flower-visiting insects in clear-cuts are rich and dynamicOriginal article

Per MILBERG, Victor ERIKSSON, Karl-Olof BERGMAN

Eur. J. Entomol. 118: 182-191, 2021 | DOI: 10.14411/eje.2021.019

Clear-cuts in production forests provide an open, sunny environment, with an abundance of nectar, as well as exposed soil and woody debris. This makes them a potential habitat for several groups of insects that typically use open habitats like grassland, including those species that visit flowers. In the current study, we used colour pan traps to catch flower-visiting species. Study sites were selected according to age (2-8 yrs since clear-cut) and land-use history (forest or meadow 150 yrs ago). We caught and identified solitary bees (395 specimens belonging to 59 species), social bees (831/16), other Hymenoptera (367/66), Syrphidae (256/31), and beetles (Lepturinae & Cetoniinae; 11,409/12). Age of the clear-cut strongly affected species composition as well as several groups and species, with most species caught mainly in the younger clear-cuts. Flower abundance statistically affected several groups and species, but inferring causation is difficult due to the flower-richness bias in pan trap catches. Bare soil and woody debris were important for the insect assemblage sampled, while bare rock was not. Although the majority of the insects caught were forest species, about one third of the species were associated with open, agricultural sites and hence seem to be able to locate and exploit resources in clear-cuts.

Quametopia, a new genus of Nearctic Anthomyzidae (Diptera), with description of two new species, immature stages and life history

Jindøich ROHÁÈEK, Kevin N. BARBER

Eur. J. Entomol. 108 (2): 287-326, 2011 | DOI: 10.14411/eje.2011.038

Quametopia gen. n. is established on the basis of recent phylogenetic analysis of taxa formerly assembled under the genus Mumetopia Melander, 1913 to include M. terminalis (Loew, 1863) and two new closely related Nearctic species of Anthomyzidae. The new genus is diagnosed and its phylogenetic relationships discussed. Quametopia terminalis (Loew, 1863) comb. n. is transferred from Mumetopia and redescribed based on revision of the type material (lectotypes of Anthophilina terminalis Loew, 1863 and its synonym Mumetopia nitens Melander, 1913 are designated) and other extensive material. Quametopia clintonia sp. n. and Q. amplistylus sp. n. (both from Canada, USA) are described and relationships of all three Quametopia species discussed. Immature stages of Q. terminalis and Q. clintonia sp. n. obtained by means of adult-to-adult rearing are described (1st- and 2nd-instar larvae for the first time in the family Anthomyzidae) and illustrated. Keys to adults, eggs, larvae and puparia of Quametopia species are presented. Biology (habitat and host-plant associations, life history) of Q. terminalis and Q. clintonia sp. n. are studied in detail and their ecological separation demonstrated. Distribution of all Quametopia species is reviewed.

Windborne migration of Auchenorrhyncha (Hemiptera) over BritainOriginal article

Don R. REYNOLDS, Jason W. CHAPMAN, Alan J.A. STEWART

Eur. J. Entomol. 114: 554-564, 2017 | DOI: 10.14411/eje.2017.070

Planthoppers (Delphacidae), leafhoppers (Cicadellidae) and froghoppers (Aphrophoridae) (Hemiptera: Auchenorrhyncha) caught during day and night sampling at a height of 200 m above ground at Cardington, Bedfordshire, UK, during eight summers (between 1999 and 2007) were consolidated with high-altitude catches made over England in the 1930s. Comparisons were made with other auchenorrhynchan trapping results from northwest Europe, which were indicative of migration. The migratory abilities in the species concerned were then interpreted in terms of various life-history traits or ecological characteristics, such as ontogenetic, diel and seasonal flight patterns, voltinism, habitat preferences, and host plant affinity. In contrast to some other areas of the world (North America, East Asia), the migratory abilities of most Auchenorrhyncha species in northwest Europe is poorly understood, and thus the present study draws together, and complements, fragmentary information on this topic as a basis for further research.

Seasonal fluctuations and development of degree-day models for Chilo partellus (Lepidoptera: Crambidae) in maize fields in the Mediterranean regionOriginal article

Tange Denis ACHIRI, Ekrem ATAKAN, Serkan PEHLIVAN

Eur. J. Entomol. 117: 68-75, 2020 | DOI: 10.14411/eje.2020.007

Chilo partellus Swinhoe 1885 (Lepidoptera: Crambidae) is a serious pest of maize in many parts of the world. It was reported for the first time in 2014 in the Mediterranean part of Turkey. Degree-Day (DD) models were developed to predict seasonal dynamics in maize fields using 3-parameter 'Boltzman' and a 4-parameter Logistic regressions. Larval/plant counts were monitored in pesticide-free maize fields in Adana, Turkey from 2017 to 2019. Depending on the year, the first record of C. partellus was between 03-14 May, corresponding to ~ 9-12 DD accumulated from 01 May. There were two main peaks; one in each of the maize growing seasons. The models accurately predicted the phenology of C. partellus with an Adj. R 2 greater than 0.80. The 'Boltzman' regression had lower AICc, ΔAICc and Wі values than the logistic regression. Based on the 'Boltzman' model, 50% of the accumulated larvae/plant count for the first and second generations (peaks) occurred at 80DD and 375DD, 81DD and 413DD, and 54DD and 289DD in 2017, 2018 and 2019, respectively. For the logistic regression model, 50% of the accumulated larvae/plant counts occurred for the first and second generation at 90DD and 362DD, 62DD, and 45DD and 250DD in 2017, 2018, and 2019, respectively. Both these models could play a crucial role in the integrated pest management (IPM) of C. partellus in maize fields in Mediterranean regions.

Fine structure of Drosophila larval salivary gland ducts as revealed by laser confocal microscopy and SEMOriginal article

Denisa BEÒOVÁ-LISZEKOVÁ, Milan BEÒO, Robert FARKA©

Eur. J. Entomol. 118: 123-134, 2021 | DOI: 10.14411/eje.2021.013

The functions of the larval salivary glands (SGs) of Drosophila are traditionally associated with the production of a massive secretion during puparium formation; it is exocytosed into a centrally located lumen and subsequently expectorated via ducts, the pharynx and mouth. This so-called proteinaceous glue serves as an adhesive to attach the puparial case to a solid substrate. Great attention has been paid to the secretory cells of SGs, which are famous for their giant polytene chromosomes. However, substantially less attention has been devoted to individual or common ducts that form the most proximal portion of the SG organ via which the glue is released into the pharynx. In the present paper, we describe the organization and fine structure of the taenidia, highly specialized circumferential ring-like extracellular (cuticular) components on the internal side of these tubes. Two chitin-specific probes that have previously been used to recognize taenidia in Drosophila tracheae, Calcofluor White M2R (also known as Fluorescent Brightener 28) and the novel vital fluorescent dye SiR-COOH, show positively stained ductal taenidia in late larval SGs. As seen using scanning electron microscopy (SEM), the interior of the ductal tube contains regular and densely-arranged ridge-like circumferential rings which represent local thickenings of the cuticle in various geometries. The microtubular arrays that optically colocalize with taenidia in both the trachea and SG ducts are specifically and strongly recognized by fluorescently-conjugated colchicine as well as anti-tubulin antibody. In contrast to taenidia in the tracheae, the analogous structures in SG ducts cannot be detected by fluorescently-labeled phalloidin or even actin-GFP fusion protein, suggesting that the ducts lack a cortical network made of filamentous actin. We speculate that these taenidia may serve to reinforce the duct during the secretory processes that SGs undergo during late larval and late prepupal stages.

Do flower mixtures with high functional diversity enhance aphid predators in wildflower strips?Original article

Séverin HATT, Roel UYTTENBROECK, Thomas LOPES, Pierre MOUCHON, Julian CHEN, Julien PIQUERAY, Arnaud MONTY, Frédéric FRANCIS

Eur. J. Entomol. 114: 66-76, 2017 | DOI: 10.14411/eje.2017.010

Among the semi-natural elements in agricultural landscapes, wildflower strips sown at field margins or within fields are potential habitats for the natural enemies of insect pests. As insects are sensitive to a variety of flower traits, we hypothesized that mixtures with high functional diversity attract and support a higher abundance and species richness of aphid flower visiting predators than mixtures with low functional diversity. During a field experiment, repeated over two years (2014 and 2015) in Gembloux (Belgium), aphid predators (i.e., lacewings, ladybeetles and hoverflies) were pan-trapped in five sown flower mixtures (including a control mixture, with three replicates of each mixture) of low to high functional diversity based on seven traits (i.e., flower colour, ultra-violet reflectance and pattern, start and duration of flowering, height and flower class, primarily based on corolla morphology). In both years, the species of flowering plants in the sown mixtures (i.e., sown and spontaneous flowers) were listed, and the realized functional diversity in each plot calculated. Over the two years, a high functional diversity was not associated with high abundance and richness of aphid predators. Moreover, ladybeetles, which made up the majority of the predators trapped, were more abundant in mixtures with very low or intermediate functional diversity at sowing, especially in 2014. We hypothesize that certain flowers, which were abundant in certain mixtures (and not in those exhibiting the highest functional diversity), attracted predators and were sufficiently abundant to support them. Our results present novel information that could be used for developing flower mixtures that provide effective ecosystem services, such as pest control.

Mating activity of Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae) in natureOriginal article

Alois HONÌK, Zdenka MARTINKOVÁ, Marek BRABEC

Eur. J. Entomol. 116: 187-193, 2019 | DOI: 10.14411/eje.2019.020

The mating behaviour of Pyrrhocoris apterus in the laboratory is well studied, but little is known about it under natural conditions. In natural populations in Central Europe, overwintered adults start copulating in March and continue until their death. Caged females, kept under natural conditions in the permanent presence of males, copulated repeatedly. Their mating activity increased sharply until early April, then very slowly until the end of June and then declined as the females die-off. Half of copulations were short (< 5 h) and only 9% were longer than 1 day. By contrast, in natural populations, mating activity (percentage of individuals involved in copula) reached its maximum in April and then decreased until early July, when the overwintered adults die. The decline in mating frequency (percentage of adults involved in copula) was associated with a decrease in the availability of receptive females towards the end of the mating period. For a female, repeated copulation is necessary because sperm is nearly depleted after insemination of 3-5 egg batches.

The Neriidae (Diptera) of Southeast Asia: A taxonomic revision of the genus TelostylusOriginal article

Tatiana A. SEPÚLVEDA, Diego de S. SOUZA, Lucas R.P. GOMES, João M. FOGAÇA, Claudio J.B. de CARVALHO

Eur. J. Entomol. 116: 281-301, 2019 | DOI: 10.14411/eje.2019.032

The Asian neriid fly genus Telostylus Bigot (Diptera: Neriidae) is revised, including a key and illustrations of its species. Lectotype designations are proposed for four species: Telostylus babiensis de Meijere, T. decemnotatus Hendel, T. remipes (Walker) and T. trilineatus de Meijere. Two new species are described: Telostylus marshalli Sepúlveda & de Carvalho, sp. n., from Sarawak, Malaysia, and T. whitmorei Sepúlveda & de Carvalho, sp. n., from Masbate, Philippines. The morphology of Telostylus binotatus Bigot and T. remipes (Walker) is discussed in order to support their synonymy. Additionally, new country records are provided for four species: Telostylus babiensis de Meijere for Philippines, T. binotatus Bigot for Papua New Guinea, T. inversus Hennig for Malaysia and Indonesia, and T. trilineatus de Meijere for Malaysia and Philippines.

SOIL-INSECT toolbox: A new chamber for analysing the behaviour of herbivorous insects and tri-trophic interactions in soilOriginal article

Ewa M. FURMANCZYK, Malgorzata TARTANUS, Zbigniew B. JÓ¬WIAK, Eligio MALUSÁ

Eur. J. Entomol. 118: 200-209, 2021 | DOI: 10.14411/eje.2021.021

A chamber, named SOIL-INSECT toolbox, was developed to analyse the effect of various factors on the behaviour of soil-dwelling insects. It is equipped with sensors that continuously monitor the concentration of CO2 in the different compartments of the chamber without disturbing the air balance in the soil. The chamber can be adapted to study different stimuli, including volatile compounds, both in the presence and absence of plants. The chamber was tested using the larvae of Melolontha spp., which confirmed its suitability for carrying out complex studies on insect-insect and insect-plant-microbiome interactions in a complex environment such as soil. The results of behavioural experiments using L3 larvae of Melolontha spp. in sterilized and natural soils revealed that the soil condition affected the behaviour of the larvae, likely due to its effect on the soil microbiome and physico-chemical characteristics.

Host condition effects upon Agrilus planipennis (Coleoptera: Buprestidae) captures on decoy-baited branch trapsOriginal article

Michael J. DOMINGUE, Jennifer BERKEBILE, Kim STEINER, Loyal P. HALL, Kevin R. CLOONAN, David LANCE, Thomas C. BAKER

Eur. J. Entomol. 113: 438-445, 2016 | DOI: 10.14411/eje.2016.057

We deployed branch traps in an ash (Fraxinus) plantation to investigate how Agrilus planipennis behavior is associated with Fraxinus pennsylvanica condition and dispersal patterns. Data were collected from traps with or without the presence of beetle visual decoys, and from a yearly survey of exit holes. The traps were placed on trees that were either clearly declining, with most foliage arising from epicormic sprouting, or on apparently healthy trees, with little evidence of damage or decline. We calculated correlations of exit holes among neighboring tree rings and also between exit holes and male trap captures. The damaged trees the traps were hung upon had more cumulative exit holes observed than the corresponding healthy trees. However, there was otherwise no evidence that the experiment was biased by differences in exit hole patterns of the surrounding trees. Male captures were greater on decoy-baited traps than controls and this decoy effect was most clearly apparent late in the season when traps were placed on healthy trees. There were also patterns of correlations between male captures and exit hole numbers that may be indicative of short-range mate finding-and dispersal behaviors. Female captures were sparser, but were positively affected by decoys on healthy and declining trees early in the season. Thus, the results suggest that the placement of such traps on healthier trees will maximize detection, and the branch traps also show promise for further use in dispersal studies.

Comparative cytogenetic analysis in 13 tortoise beetles (Coleoptera: Chrysomelidae: Cassidinae) from BrazilOriginal article

Amália T. LOPES, Flávia R. FERNANDES, Marielle C. SCHNEIDER

Eur. J. Entomol. 113: 352-363, 2016 | DOI: 10.14411/eje.2016.046

In the present work, we have characterized the chromosomes of 13 Cassidinae beetles, belonging to four tribes, the broad aim being to increase the cytogenetic data and establish the mechanisms involved in chromosome evolution of this subfamily, which appear to be conserved karyotypically, i.e. 2n = 16 + Xyp. The analysis of mitotic and meiotic cells revealed a high diversity of diploid numbers (2n = 18, 2n = 22, 2n = 26, 2n = 32, 2n = 36, 2n = 40, 2n = 42), and the presence of sex chromosome system of the Xyp type in most species, with the exception of two representatives that exhibited Xyr and XY systems. C-banding showed constitutive heterochromatin predominantly localized in the pericentromeric region of the chromosomes, but differences regarding the number of chromosomes with positive C-bands, intensity of the blocks, and presence of additional bands in autosomes and/or sex chromosomes were observed among the species investigated. Our data revealed that the karyotype 2n = 16 + Xyp does not occur in all 13 tribes of the Cassidinae characterized cytogenetically, seeming to be only a shared feature among the species of the Cassidini. Variations in the C-band pattern, mainly in closely related species, suggest that the interspecific karyotype diversification occurred as a result of changes in the quantity and distribution of constitutive heterochromatin. The occurrence of the Xyp sex chromosome system in the tribe Mesomphaliini, which showed the highest diversity of simple and multiple systems among the coleopteran as a whole, reinforces the view that derived systems originated by chromosome rearrangements involving the Xyp ancestral system.

Efficacy of semiochemical-baited traps for detection of longhorn beetles (Coleoptera: Cerambycidae) in the Russian Far East

Jon D. SWEENEY, Peter J. SILK, Vasily GREBENNIKOV

Eur. J. Entomol. 111 (3): 397-406, 2014 | DOI: 10.14411/eje.2014.049

The efficacy of various combinations of pheromones and plant volatile lures for detection of longhorn beetles (Coleoptera: Cerambycidae) in traps was tested in field bioassays in a mixed coniferous-deciduous forest near Vladivostok in the Russian Far East in 2009 and 2010. Traps detected 30 species (490 specimens) in 2009 and 23 species (182 specimens) in 2010. Overall, 38 longhorn beetle species were detected, with 15 species common to both years. Species composition differed among lure treatments, but the number of species detected with any single lure did not vary significantly among lures (12-16 species per lure in 2009; 3-10 species per lure in 2010). Type of lure significantly affected mean catch per trap of five species in 2009 and 2010. For these same species, lure type also significantly affected the efficacy of detection, i.e., the proportion of traps that captured at least one specimen of a given species. The combination of racemic E-fuscumol and spruce blend (a blend of five monoterpenes) positively affected mean catch of Tetropium castaneum (L.). Racemic 3-hydroxyhexan-2-one (K6), alone or combined with ethanol, increased mean catch of Anaglyptus colobotheoides Bates. The combination of K6 and ethanol increased mean catch of Phymatodes testaceus (L.), and the combination of racemic 3-hydroxyoctan-2-one and ethanol increased mean catch of Molorchus minor (L.). Use of longhorn beetle pheromone lures in trapping surveys increases the mean catch and probability of detecting certain species of Cerambycidae, including those that may be exotic and potentially invasive. Sample-based rarefaction indicated that eight traps per site were insufficient to detect all of the longhorn species potentially attracted by any individual lure treatment, i.e., species accumulation curves failed to reach an asymptote in most cases.

Fungi associated with Ips acuminatus (Coleoptera: Curculionidae) in Ukraine with a special emphasis on pathogenicity of ophiostomatoid speciesOriginal article

Kateryna DAVYDENKO, Rimvydas VASAITIS, Audrius MENKIS

Eur. J. Entomol. 114: 77-85, 2017 | DOI: 10.14411/eje.2017.011

Conifer bark beetles are well known to be associated with fungal complexes, which consist of pathogenic ophiostomatoid fungi as well as obligate saprotroph species. However, there is little information on fungi associated with Ips acuminatus in central and eastern Europe. The aim of the study was to investigate the composition of the fungal communities associated with the pine engraver beetle, I. acuminatus, in the forest-steppe zone in Ukraine and to evaluate the pathogenicity of six associated ophiostomatoid species by inoculating three-year-old Scots pine seedlings with these fungi. In total, 384 adult beetles were collected from under the bark of declining and dead Scots pine trees at two different sites. Fungal culturing from 192 beetles resulted in 447 cultures and direct sequencing of ITS rRNA from 192 beetles in 496 high-quality sequences. Identification of the above revealed that the overall fungal community was composed of 60 species. Among these, the most common were Entomocorticium sp. (24.5%), Diplodia pinea (24.0%), Ophiostoma ips (16.7%), Sydowia polyspora (15.1%), Graphilbum cf rectangulosporium (15.1%), Ophiostoma minus (13.8%) and Cladosporium pini-ponderosae (13.0%). Pathogenicity tests were done using six species of ophiostomatoid fungi, which were inoculated into Scots pine seedlings. All ophiostomatoid fungi tested successfully infected seedlings of Scots pine with varying degrees of virulence. Ophiostoma minus was the only fungus that caused dieback in inoculated seedlings. It is concluded that I. acuminatus vectors a species-rich fungal community including pathogens such as D. pinea and O. minus. The fungal community reported in the present study is different from that reported in other regions of Europe. Pathogenicity tests showed that O. minus was the most virulent causing dieback in seedlings of Scots pine, while other fungi tested appeared to be only slightly pathogenic or completely non-pathogenic.

The year-round phenology of the migratory Red Admiral Vanessa atalanta (Lepidoptera: Nymphalidae) in a Mediterranean area in southern SpainOriginal article

Mariano CUADRADO

Eur. J. Entomol. 114: 517-525, 2017 | DOI: 10.14411/eje.2017.066

Many studies report the migratory status of Vanessa atalanta in the Palearctic. Available evidence indicates that this species migrates north in spring to reproduce and south in autumn to reproduce in the Mediterranean area. However, little is known about the year-round phenology and their overwintering in southern regions. Here, I present data on the year-round phenology of adult V. atalanta recorded during a three year period (2014-2016) at 5 lowland sites (< 80 m a.s.l.) near the coast close to Cádiz (southern Spain). Overall, a total of 826 imagoes were recorded along 1499.3 km of Butterfly Monitoring Scheme (BMS) transects. Abundance was 0.55 butterflies/km (data for all sites and years pooled) and varied greatly among sites and years. Coinciding with the migratory status, imagoes were recorded from September to June each year and the year-round abundance showed a typical bimodal distribution with two peaks of abundance, one in late winter (February) and another in autumn (November). Abundance was higher in spring (0.87 butterflies/km) than in autumn (0.60 butterflies/km). The emergence of a local generation in late winter was also recorded. My results agree with the migratory phenology of this species in the Palearctic and support the year round phenology data reported by Stefanescu (2001).

Influence of a diet containing tobacco on the biology of Ephestia kuehniella (Lepidoptera: Pyralidae) and its parasitoid Habrobracon hebetor (Hymenoptera: Braconidae)Original article

Cleder PEZZINI, Simone MUNDSTOCK JAHNKE, Andreas KÖHLER

Eur. J. Entomol. 117: 190-198, 2020 | DOI: 10.14411/eje.2020.020

Host diet often influences its biological parameters and the success of their parasitoids, both in mass rearing, field research and parasitism in applied biological control programs. Habrobracon hebetor (Say, 1836) (Hymenoptera: Braconidae) is an important biological control agent of the flour moth Ephestia kuehniella (Zeller, 1879) (Lepidoptera: Pyralidae), which infests tobacco, grain and other products in storage. This study aimed to evaluate the effect of different proportions of tobacco in artificial diets on the biological parameters of the host E. kuehniella and its parasitoid H. hebetor. Four classes of Virginia tobacco with different sugar and nicotine concentrations were added to flour diets for moths in different percentages (5, 10 and 15%).The experimental design was completely randomized in a 3 × 4 factorial scheme (percentage of dietary tobacco × class of tobacco). In the parasitoid bioassays, hosts fed only with 5% tobacco were used. For E. kuehniella, the development time (egg-adult), viability of immature stages, sex ratio, fecundity, egg viability and longevity were measured. For H. hebetor, percentage parasitism, offspring sex ratio, number of paralyzed and parasitized larvae, egg-adult viability and parasitism preference were measured. Tobacco classes and percentages added to the diet influenced the development time and viability of E. kuehniella. The 5% host diet did not influence the different biological parameters and behaviour of H. hebetor. For mass rearing of H. hebetor, it is unnecessary to add tobacco to the artificial diet in order to improve parasitoid performance.

Cannibalism among same-aged nymphs of the omnivorous predator Dicyphus errans (Hemiptera: Miridae) is affected by food availability and nymphal densityOriginal article

Konstantina ARVANITI, Argyro FANTINOU, Dionyssios PERDIKIS

Eur. J. Entomol. 116: 302-308, 2019 | DOI: 10.14411/eje.2019.033

Cannibalism, the act of eating an individual of the same species has been little studied in omnivorous insect predators. Dicyphus errans (Wolff) (Hemiptera: Miridae) is a generalist omnivorous predator that commonly occurs in tomato greenhouses and field crops in the Mediterranean basin. In this work cannibalism among same-aged neonate nymphs of D. errans was studied when 1, 2, 4, 8 or 16 individuals were placed in a Petri dish along with or without heterospecific prey. Although nymphs were unable to complete their development in the absence of prey they survived longer when there were initially 2 individuals per dish than in any other treatment including a single individual. This may indicate that cannibalism in this predator has positive effect on nymphal survival, which however was not the case at higher densities. The presence of heterospecific prey increased nymphal survival and individuals were as equally successful in completing their development as when kept singly. Developmental time in all the treatments was very similar. Adult weight of both females and males was significantly greater when a nymph was reared alone and similar in all the other treatments. The results indicate that cannibalism occurs among neonates of D. errans if heterospecific prey is scarce and has a negative effect on adult weight when heterospecific prey is abundant. This should be considered in studies on enhancing the biocontrol efficiency or mass rearing of this predator.

Unusual chromosome polymorphism and heterochromatin variation in the Argentinean population of the necrophagous fly Lucilia sericata (Diptera: Calliphoridae), comparison with other populations and evolutionary aspectsOriginal article

Mónica Gabriela CHIRINO, María Florencia FOURASTIE, Néstor Daniel CENTENO, María José BRESSA

Eur. J. Entomol. 117: 295-301, 2020 | DOI: 10.14411/eje.2020.034

Heterochromatin may vary qualitatively, quantitatively, and in its location both in and between species. There were differences recorded in sex chromosomes, satellite sizes and location of C-bands in specimens of Lucilia sericata (Meigen, 1826) from three localities in the Buenos Aires region, Argentina (Bernal, Castelar, and Buenos Aires City). Mitotic analyses revealed the same diploid chromosome number of 2n = 10 + XY / XX (male / female) and the same size, morphology, and C-banding patterns on their autosomes. However, there are different morphotypes of X and Y chromosomes with a distinctive heterochromatin content in both arms. Four morphotypes of X (X1, X2, X3, and X4) and three of Y (Y1, Y2, and Y3) were recorded. The X metacentric and Y subtelocentric chromosomes were identified based on their very large and small sizes, respectively, and both had large heterochromatic blocks. These intraspecific differences are mainly due to quantitative variations in non-coding repetitive sequences located in the arms of both X and Y sex chromosomes. The specimens were very polymorphic both between and within the three localities sampled. Cytogenetic studies on specimens of L. sericata from the Nearctic, Palaearctic and Ethiopian regions also report differences in the morphology of the sex chromosomes and their C-banding patterns, some of which may have evolved independently. Our cytogenetic observations on L. sericata indicate that the accumulation of heterochromatin in the genome could be involved in chromosomal divergence and karyotype evolution of this species, as demonstrated in other Diptera. The polymorphic sex chromosomes are therefore important for understanding the evolution within species as well as speciation.

Tendency and consequences of superparasitism for the parasitoid Ooencyrtus pityocampae (Hymenoptera: Encyrtidae) in parasitizing a new laboratory host, Philosamia ricini (Lepidoptera: Saturniidae)Original article

Hilal TUNCA, Maurane BURADINO, Etty-Ambre COLOMBEL, Elisabeth TABONE

Eur. J. Entomol. 113: 51-59, 2016 | DOI: 10.14411/eje.2016.006

The tendency for self-superparasitism and it's effects on the quality of the parasitoid Ooencyrtus pityocampae (Mercet) (Hymenoptera: Encyrtidae) in parasitizing a new laboratory host, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae), were investigated. In this study, female parasitoids of various ages (1-, 3- and 5-day-old) were tested individually. Parasitoids were provided with 1-day-old P. ricini eggs at ratios of 5, 10, 20, 30 and 40 host eggs per wasp. The tendency to superparasitize was dependent on the female's age and host density. Five-day-old females showed a strong tendency to superparasitize at low host densities. The development time of wasps in superparasitized eggs was longer than that of wasps in singly parasitized eggs. The size and longevity of adult parasitoids decreased significantly with superparasitism. This work contributes to the development of an efficient mass rearing and laboratory rearing of the parasitoid O. pityocampae using a new host.

Two new species and one new record for the genus Copris (Coleoptera: Scarabaeidae: Scarabaeinae) from Vietnam with a key to Vietnamese speciesOriginal article

Van Bac BUI, Kenneth DUMACK, Michael BONKOWSKI

Eur. J. Entomol. 115: 167-191, 2018 | DOI: 10.14411/eje.2018.016

Two new species of Copris Geoffroy, 1762 are described and illustrated: Copris (subgenus incertae sedis) caobangensis sp. n. from Caobang Province (northern Vietnam) and Copris (Copris) sonensis sp. n. from Thanhhoa Province (central Vietnam). Copris (Copris) szechouanicus Balthasar, 1958 is recorded in Vietnam for the first time and data on the morphology, distribution and ecology of this species are given. An updated species list and an identification key for the Copris species so far known from Vietnam are presented along with detailed photographs of the poorly known species.

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