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Results 151 to 180 of 1606:

Urbanisation and forest size affect the infestation rates of plant-galling arthropods and damage by herbivorous insectsOriginal article

Sandro MEYER, Hans-Peter RUSTERHOLZ, Bruno BAUR

Eur. J. Entomol. 117: 34-48, 2020 | DOI: 10.14411/eje.2020.004

Urbanisation is increasing globally and is considered to be a main driver of environmental change. Urbanisation-related factors include reduced habitat size and increased spatial isolation of the remaining habitats. As a consequence, the dynamics of plant and animal populations may change, which in turn might influence the quality and quantity of plant resources. Thus, urbanisation has the potential to disturb plant-animal interactions such as herbivory or galling. In the urban-rural setting of Basel (Switzerland), we aimed to assess whether the degree of urbanisation and forest size influence plant-galling infestation rates and leaf damage by mining and chewing arthropods on three tree species (sycamore, beech, and ash). We recorded species-specific responses to the degree of urbanisation and forest size. Gall infestation rate on sycamore leaves was affected by urbanisation but not by forest size. In contrast, gall infestation rates of beech gall midges responded sensitively to increasing urbanisation and decreasing forest size. The total leaf area damage caused by mining and chewing arthropods on sycamore was influenced by urbanisation and increased with increasing forest size. Leaf area damage by miners in beech tended to be affected by the degree of urbanisation, but not in ash. Urbanisation and forest size have the potential to alter herbivorous insect abundances. However, the effects depend on tree species and herbivore guild.

Seasonal and geographical adaptations in the parthenogenetic stick insect, Ramulus mikado (Phasmatodea: Phasmatidae)Ivo Hodek special issueOriginal article

Keiji NAKAMURA, Yuuki FUKUSHIMA

Eur. J. Entomol. 119: 354-361, 2022 | DOI: 10.14411/eje.2022.036

Seasonal and geographical adaptations in terms of obligatory embryonic diapause in the parthenogenetic stick insect, Ramulus mikado, were studied. First and second instar nymphs were collected at locations at three latitudes in Japan and reared in the laboratory under a photoperiod of 16L : 8D or 12L : 12D at 25°C. Their eggs were kept at 30°C for 30 or 60 days after oviposition, but no eggs hatched. Hatching was observed more than 100 days after transfer from 30°C to 15°C. The long period between transfer and hatching indicate that eggs in an early embryonic stage of development enter diapause at high-temperatures. The time from oviposition to hatching of eggs laid by adults that originated from the three locations kept under constant conditions between 15 and 25°C were compared. In all these experiments, eggs laid by individuals originating from high latitudes took longer to hatch. The eggs of those originating from Okayama and Ehime did not hatch at 25°C. However, more than 80% of the eggs of those that originated from the northernmost population hatched. Hatching before winter was observed when the eggs of those that originated from the northern population were placed outdoors in Okayama, even when the maternal insects were reared under long-day conditions in the laboratory. These findings indicate that univoltine R. mikado enters diapause twice during embryonic development, which enables it survive adverse conditions in summer and winter, respectively. Furthermore, diapause intensity was lowest in insects that originated from the lowest latitude.

A review of the genus Mecistorhabdia (Lepidoptera: Erebidae: Arctiinae: Syntomini) with a description of a new species from the Central African RepublicOriginal article

Nikolai IGNATEV, Beata GRZYWACZ, Łukasz PRZYBYŁOWICZ

Eur. J. Entomol. 117: 139-148, 2020 | DOI: 10.14411/eje.2020.016

The genus Mecistorhabdia Kiriakoff, 1953 is reviewed and one new species M. sulaki sp. n. from the Central African Republic and Cameroon (Afrotropical region) described. The holotype female of the type species M. haematoessa (Holland, 1893) is matched with a conspecific male using a molecular technique. M. burgessi Kiriakoff, 1957 is removed from the synonymy as it is considered to be a valid species. Habitus and male genitalia of all three species are illustrated along with the female genitalia of M. haematoessa. A key for identification of species based on the structure of male genitalia and a map of their distribution are provided. The results of a study of the genetic diversity of the three species of Mecistorhabdia, based on cytochrome c oxidase subunit I gene, are presented. Relationships between species are briefly discussed.

The association of the development of the internal reproductive organs of male desert locusts, Schistocerca gregaria (Orthoptera: Acrididae), with age, phase and the effect of exposure to pheromonesOriginal article

Satoshi HIROYOSHI, Takayuki MITSUNAGA, Gadi V.P. REDDY

Eur. J. Entomol. 119: 300-308, 2022 | DOI: 10.14411/eje.2022.031

The regulation of the development of the male reproductive organs in insects is still an open question. Although the desert locust, Schistocerca gregaria, has been extensively examined, there is little information on the effects of phase and pheromones on the development of the male reproductive organs. This study clarified the association of these two factors with reproductive development (length or width of each organ) of the testis, testicular follicles, accessory glands, and seminal vesicles in this locust. The width of the follicles and width and length of the accessory gland mass are significantly associated with phase (solitary or gregarious). Developmen of all reproductive organs is age dependent as these organs developed in the adult stage. The development of follicles and accessory glands (width) in males in the first two weeks of adulthood was promoted by exposing them to pheromones from mature adults, but not from nymphs. These results indicate the incidence of male reproductive development is associated with phase and affected by pheromones.

Experimental evidence of polyandry and prolonged copulations in Photinus palaciosi, a synchronous firefly with brachypterous females (Coleoptera: Lampyridae)Original article

Aldair VERGARA, Tania LÓPEZ-PALAFOX, Jaime CAMACHO-GARCÍA, David XOCHIPILTECATL, Crisóstomo MIXTLI, Carlos CORDERO

Eur. J. Entomol. 120: 293-296, 2023 | DOI: 10.14411/eje.2023.029

Males of some species of the firefly Photinus produce nutritious spermatophores (nuptial gifts) the production of which is associated with a specific reproductive morphology. In fireflies and other insects, the production of nuptial gifts favours the evolution of polyandry. On the other hand, in fireflies, wing reduction (brachyptery) in females is associated with the lack of nuptial gifts. P. palaciosi is a synchronous firefly with brachypterous females, which would indicate an absence of nuptial gifts and a monandrous mating system. However, the reproductive morphology of P. palaciosi is like that of species producing nuptial gifts, which indicates this species should be polyandrous. Here, the results of an experimental study designed to test if females of the synchronous firefly Photinus palaciosi are polyandrous or monandrous are reported. The duration of copula was determined because this trait is associated with absence/presence of nuptial gifts in fireflies: it is very short (few minutes) in species lacking nuptial gifts and long (hours) in gift-giving species. More than sixty percent of the females mated with several males and the duration of each copulation was long. Thus, these results, together with those of previous studies on the morphology of the reproductive system, strongly indicate that males produce spermatophores (which usually contain nutrients and are, thus, considered nuptial gifts), which provides a possible explanation of both polyandry and prolonged copulations in P. palaciosi.

Influence of forest decline on the abundance and diversity of Raphidioptera and Mecoptera species dwelling in oak canopiesOriginal article

Alexis VINCENT, Pierre TILLIER, Cécile VINCENT-BARBAROUX, Christophe BOUGET, Aurélien SALLÉ

Eur. J. Entomol. 117: 372-379, 2020 | DOI: 10.14411/eje.2020.041

Trees in a state of decline exhibit a reduced foliage density and accumulate dead branches in their crowns. Consequently, forest decline can markedly affect both the habitats and sources of food for canopy-dwelling insects. The decline-induced increase in canopy openness may also modify the understory, shrub and ground layers, and have cascading effects on associated species. Flight interception traps and green Lindgren traps were used to survey the canopy-dwelling insects in stands of healthy and declining oak trees, in particular two insect orders: Raphidioptera, saproxylic insects associated with canopies, and Mecoptera, necrophagous or opportunistic species associated with the herbaceous or shrub strata. Overall, green Lindgren traps caught more of these insects than flight interception traps. The traps caught five species of Raphidioptera. Three of them, Subilla confinis, Phaeostigma major and, to a lesser extent, Phaeostigma notata, were more abundant in stands or plots with declining trees. However, the other two species of Raphidioptera, Atlantoraphidia maculicollis and Xanthostigma xanthostigma exhibited a reverse trend. Two species of Mecoptera, Panorpa germanica and Panorpa communis, were particularly abundant, but unaffected by the level of decline. Our results show that declining forests can either host more or fewer species of Raphidioptera with saproxylic larvae, whereas Mecoptera with ground-living larvae were unaffected. Seasonal phenology and sex ratio of the species are also discussed.

Provision of small sterile eggs is a circumstance-dependent maternal investment in sibling cannibalism in the ladybird beetle Harmonia axyridis (Coleoptera: Coccinellidae)Ivo Hodek special issueOriginal article

Naoya OSAWA

Eur. J. Entomol. 119: 133-139, 2022 | DOI: 10.14411/eje.2022.014

Many aphidophagous ladybird beetles lay clusters of eggs and sibling cannibalism occurs at hatching. Larvae that hatch early tend to cannibalize undeveloped eggs and those that hatch late. The cannibalized eggs, especially those that are sterile, represent a maternal investment in the cannibal and are regarded as "trophic" eggs, which increase their chances of surviving. The characteristics of cannibalized eggs, however, are poorly studied. In this study, I determined the sizes of eggs that developing and undeveloped eggs within egg clusters of Harmonia axyridis (Coleoptera: Coccinellidae). Developing eggs were significantly larger (on average 3.45% larger) than the undeveloped sterile ones, which were mainly small. Furthermore, the hatchability of eggs was also significantly associated with their size, inclusive of the maternal effects. These results indicate that the production of relatively small sterile eggs functions as circumstance-dependent maternal investment in improving the survival of the first instar larvae to hatch in each egg cluster.

Gastrophysa viridula (Coleoptera: Chrysomelidae) in the Czech Republic: Decline in a once abundant invasive oligophagous consumer of RumexOriginal article

Zdenka MARTINKOVA, Alois HONEK, Pavel SASKA

Eur. J. Entomol. 118: 250-254, 2021 | DOI: 10.14411/eje.2021.026

While the progress of the spread of invasive species of insects in new geographical areas are usually intensively monitored, the decline of these species often escape attention and is poorly documented. In this study, we record the decline in abundance of Gastrophysa viridula (DeGeer), an invasive oligophagous consumer of dock (Rumex spp.). This species originally inhabited Alpine regions. In the late 1800s, G. viridula was recorded in montane areas in the Czech Republic and then throughout this country. Gastrophysa viridula was very abundant in 1995-1999, when we found it in all of the 177 stands of R. obtusifolius inspected in western Czech Republic. In a repeated study of its occurrence in the same area from 2019-2020, this species was present in < 30% of 434 of the stands inspected and was only abundant (≥ 55% of plants in the stand infested by G. viridula) in < 4% of these stands. Thus the local occurrence and abundance of G. viridula had decreased significantly. Of the possible reasons for this decline the most probable are the effect of climate warming on host plant seasonality, changes in agricultural use of grasslands and fragmentation of large stands of dock.

Presence after three decades of red wood ants (Formica rufa group; Hymenoptera: Formicidae) in forests in an agricultural landscapeOriginal article

Harry J.M. VAN BUGGENUM

Eur. J. Entomol. 119: 85-91, 2022 | DOI: 10.14411/eje.2022.009

Conducting a repeat study of the presence of mound-building red wood ants (Formica rufa group) after a period of 30 years has rarely been done in Europe. From 1990 to 2020 such a study was done in an intensively used agricultural landscape with fragments of forest in the South-Eastern part of The Netherlands. In 1990, 280 nest mounds of three species of red wood ants and a hybrid were found in the forests and along forest edges. The highest occupancy was in forests of > 25 ha. The connectivity between the forest fragments mainly determined their presence. In 2020, only 160 nest mounds were found. The development of the colonies differed for Formica polyctena Förster, 1850 (slight decrease), F. rufa Linnaeus, 1761 (substantial increase) and F. pratensis Retzius, 1783 (strong decrease). The differences between the species in this highly fragmented landscape may be due to differences in their colonization strategies of either nest splitting or producing swarms of young queens. Furthermore, the analyses show that the type of environment (in a forest or along a forest edge) determines the probability of extinction or settlement. There is a need to undertake management measures to prevent the extinction of species of red wood ants in the area studied. These measures include creating small clearings in dense forests, reducing shading due to overgrowing shrubs or herbaceous plants, and creating buffer zones around intensively manured fields. More long-term monitoring is needed in Europe to compare the circumstances in different regions, detect trends and evaluate the effects of protection measures.

First fossil representative of the tribe Amphignomini (Hemiptera: Fulgoromorpha: Achilidae) from mid-Cretaceous Kachin amber and its significanceOriginal article

Alicja Magdalena BRYSZ, Patrick MÜLLER, Jacek SZWEDO

Eur. J. Entomol. 120: 42-49, 2023 | DOI: 10.14411/eje.2023.006

A new genus Amphignokachinia Brysz & Szwedo, gen. n. and species Amphignokachinia subversa Brysz & Szwedo, sp. n. of Achilidae (Hemiptera) planthoppers of the tribe Amphignomini are described. It is the second genus and first fossil representative of the tribe Amphignomini coming from the Cenomanian amber in Kachin State, Myanmar. Diagnosis of the tribe is revised and its position in respect of fossils in the family Achilidae is discussed.

The proteins involved in larval colouration in the cuticle and haemolymph of two strains of Antheraea pernyi (Lepidoptera: Saturniidae)Short Communication

Guobao WANG, Jiangrun WANG, Lei NIE

Eur. J. Entomol. 120: 310-315, 2023 | DOI: 10.14411/eje.2023.032

The proteome profiles of the cuticle and haemolymph of two strains of the Chinese Oak silk moth A. pernyi, with cyan and yellow coloured bodies, were compared in order to identify the differentially expressed proteins (DEPs) that determine the differences in the colouration of the two strains. A total of 324 DEPs, including 124 up-regulated and 200 down-regulated proteins, were identified in the cuticles of the cyan and yellow coloured individuals, and 286 DEPs including 79 up-regulated and 207 down-regulated proteins in the haemolymph of the cyan and yellow coloured individuals. Several DEPs associated with the colour of larvae of A. pernyi were screened, including an ommochrome-binding protein, juvenile hormone esterase, protein yellow, L-dopachrome tautomerase yellow-f2 and fumarylacetoacetase, the expression levels in the cuticle and haemolymph of the yellow larvae were higher than those in the cyan coloured larvae, indicating their possible roles underlying the colouration of the yellow larvae of A. pernyi.

Feeding habits of the endangered Japanese diving beetle Hydaticus bowringii (Coleoptera: Dytiscidae) larvae in paddy fields and implications for its conservationOriginal article

Reiya WATANABE, Shin-Ya OHBA, Tomoyuki YOKOI

Eur. J. Entomol. 117: 430-441, 2020 | DOI: 10.14411/eje.2020.047

The diving beetle Hydaticus bowringii Clark, 1864 (Coleoptera: Dytiscidae) is on the Red List of Japan as 'Near Threatened'. However, there is no quantitative information on the feeding habits of its larvae, which could be used to aid its conservation. In order to determine the prey that are important for the survival and growth of larvae of H. bowringii, we combined the results of field surveys of paddy fields and rearing experiments. In the field, H. bowringii larvae predominantly feed on tadpoles of five species of frogs and occasionally also on insects, loaches and worms. The phenology of the tadpoles was similar to that of larvae of H. bowringii, as their abundances increased from May to June and decreased in July. Experimentally reared larvae of H. bowringii grew faster when fed tadpoles than when fed Sigara nymphs or a mixture of both prey, and more emerged as adults when tadpoles were included in their diet. Adults were larger in the tadpole treatment than in the Sigara treatment. Based on these results, we conclude that tadpoles are more suitable prey for the survival and growth of larvae of H. bowringii than insects. The decline in the abundance of frogs could be one of the factors determining the decrease in the local abundances of H. bowringii. In conclusion, we affirm that in order to conserve populations of H. bowringii it is crucial to maintain paddy field environments in which frogs are abundant.

The effect of temperature and photoperiod on the time taken for a meal to pass through the gut, defecation and digestion in the last larval instar of Spodoptera littoralis (Lepidoptera: Noctuidae)Original article

Esmat HEGAZI, Wedad KHAFAGI, Essam AGAMY, Ibrahim ABDALLAH

Eur. J. Entomol. 119: 398-404, 2022 | DOI: 10.14411/eje.2022.041

Spodoptera littoralis (Boisduval) is a highly destructive and polyphagous insect pest of great economic importance. It develops throughout the year and the larvae are non-diapausing. Little work has been done on the time taken for food to pass through the gut of S. littoralis. Thus, this study on starving and well fed last instar larvae of S. littoralis aimed to determine the effect of temperature and photoperiod on the time taken for a meal to pass through the gut, defecation and digestion. The results indicate that it depended on temperature, photoperiod and hunger. The time that elapsed between a larva being fed and the production of the first faecal pellet, which is a measure of the time it takes for food pass to pass through the gut (SFP), differed significantly at different temperatures and photoperiods. The SFP was longer at 15°C than at 30°C. At 20°C and under a short photoperiod, SFP was very much shorter than under a long photoperiod (18L : 6D). In addition, at 20°C, the time to defecation was significantly longer under a photoperiod of 12L : 12D than under continuous light. In all the tests > 95% of the larvae produced four faecal pellets per meal. The digestibility values varied significantly in the different tests. This study offers new insights into the passage of food from the crop to the rectum at different temperatures and photoperiods. This might help in understanding the adaptability of S. littoralis and may also help in controlling this important pest.

A dichotomous key and checklist for Mexican Athysanini leafhopper genera (Hemiptera: Cicadellidae) with a new species from the Oaxacan dry tropical forestOriginal article

J. Adilson PINEDO-ESCATEL, Christopher H. DIETRICH, James N. ZAHNISER, Gustavo MOYA-RAYGOZA, Liberato PORTILLO

Eur. J. Entomol. 118: 255-278, 2021 | DOI: 10.14411/eje.2021.027

Most Neotropical forest-dwelling leafhopper species are rare and exhibit limited distributions. The Mexican leafhopper fauna is known to be highly diverse and identification of genera and species is difficult because no attempts have been made to provide comprehensive identification tools for the fauna. Here, a dichotomous key to all genera recognized within Mexico of the diverse but little studied leafhopper tribe Athysanini is provided. Spinulana josefinae Pinedo-Escatel sp. n. is described and illustrated based on specimens collected in the dry tropical forest of Oaxacan mountains. A total of 46 genera and 146 species are now recognized in the checklist of Athysanini of Mexico. Notes on type repositories, distributional data and maps, and selected references are provided.

The northward spread of the European mantis, Mantis religiosa (Mantodea: Mantidae): Data from LithuaniaOriginal article

Jolanta RIMŠAITĖ, Povilas IVINSKIS, Galina BARTKEVIČIENĖ, Rasa BERNOTIENĖ

Eur. J. Entomol. 119: 318-326, 2022 | DOI: 10.14411/eje.2022.033

Geographic distribution of the European mantis, Mantis religiosa (Linnaeus, 1758) in Europe covers mostly southern and central Europe, but this species has recently shown a significant northward spread. First reports of M. religiosa in Lithuania were in 2008 and now these insects are distributed throughout this country. Information on the spread of M. religiosa in Lithuania between 2015 and 2020 are analysed in this paper. The spread of this insect in Lithuania and neighbouring countries can be related to changes in climate, in particular, the increase in average annual temperature and milder winters. Possible routes along which M. religiosa spread northwards based on an analysis of mtDNA sequences are presented.

Perennial alternative crops for biogas production increase arthropod abundance and diversity after harvest - results of suction sampling and metabarcodingOriginal article

Johannes BURMEISTER, Bernd PANASSITI, Franziska HEINE, Sebastian WOLFRUM, Jerome MORINIERE

Eur. J. Entomol. 120: 59-69, 2023 | DOI: 10.14411/eje.2023.009

The effects of novel perennial energy crops on arthropod abundance and diversity were tested using three field trials in Bavaria. Established cup plant (Silphium perfoliatum), Virginia mallow (Sida hermaphrodita) and tall wheat grass (Thinopyrum ponticum) plots were sampled in autumn using a modified leaf blower and their arthropod faunas compared with that recorded in maize plots. At the time of sampling, maize, cup plant and Virginia mallow had already been harvested and samples from the remaining stubble were compared with those from open ground. Collembola were the most abundant group. The highest abundance and diversity of arthropods was recorded in tall wheat grass, with Hemiptera and Aranea especially benefitting from the green and taller vegetation. Post-harvest cup plant and Virginia mallow plots harboured a more diverse and more abundant arthropod assemblage than maize plots. Stubble was identified as a suitable habitat for arthropods in agricultural fields. In conclusion, the integration of perennial energy crops into existing biogas production systems could play an important role in supporting arthropods in agricultural landscapes by providing crucial structures and resources, such as the grassy vegetation of tall wheat grass in autumn and the long-lasting stubbles of cup plant and Virginia mallow.

Comparative micro-computed tomographic analysis of the structure of brood cells and its effect on the development of the pupae of honey bee (Apis mellifera)Original article

Tamás SIPOS, Tamás DONKÓ, Ádám CSÓKA, Tamás KISS, Sándor KESZTHELYI

Eur. J. Entomol. 120: 9-14, 2023 | DOI: 10.14411/eje.2023.002

Most beekeepers worldwide use the same combs in their hives for many years, which can result in alterations in the inner volume of the comb cells. The objective of this survey using microcomputed tomography was to reveal developmental disorders caused by this beekeeping practice. The extent of the thickening of the wall of brood cells that occurs as a result of the long-term use of the combs was determined. This alteration resulted in a reduction in the inner volume of the comb cells, which had a significant effect on the size of the pupae and possibly the health of the imagoes. The walls of the cells can be divided into two well-determined parts, which can be exactly visualized using micro-CT. In addition, the inner structure of the wall in the first part of the cell was altered by very radio dense remains of cocoons. The material in the other part of the cell is less radio dense and as previously suggested is mainly wax. The decrease in the length, surface and volume of these cells adversely affected the developing pupae, which according to previous studies results in a reduction in the production of workers, colony strength and honey yield. The extent of the reduction in the body regions of pupae was on average 4.98%. Overall, the volume of the pupae that developed in these narrow comb cells were smaller by an average of 12.22%.

Plant essential oils induce expression of heat shock proteins and antioxidant enzyme activity in carob moth, Ectomyelois ceratoniae (Lepidoptera: Pyralidae)Original article

Saeed FARAHANI, Ali R. BANDANI

Eur. J. Entomol. 120: 161-169, 2023 | DOI: 10.14411/eje.2023.021

Rising concerns about the negative effects of chemical compounds in pest control have made it increasingly necessary to find new environmentally friendly compounds to combat insect pests. In recent years, the use of plant derivatives, such as, essential oils have proved very promising. Despite the many studies on essential oils, there are very few studies on the effect of these oils on induction of Heat shock proteins (HSPs) and antioxidant enzymes. Therefore, it was hypothesized that the exposure of insects to essential oils induce stress, which it is likely induces the production of heat shock proteins and antioxidant enzymes. Thus, Ectomyelois ceratoniae Clark (Lepidoptera: Pyralidae) was used as a model insect to study the lethal and sublethal effect of the fumigant toxicity of the essential oils extracted from the plants Thymus daenensis Celak and Satureja khuzistanica Jamzad. Gas Chromatography/Mass Spectrometry indicated that thymol and carvacrol were the major component of T. daenensis and S. khuzistanica extracts, respectively. Exposing E. ceratoniae to sublethal doses of the essential oils (LC30) and using RT-qPCR indicated that the expression levels of HSP70 and HSP90 were significantly increased. Activities of antioxidant enzymes including SOD, CA, POX, GST and the concentration of MDA increased following exposure to sublethal doses of both essential oils. These findings clearly show that in addition to the reported effects of essential oils, oxidative stress and induction of free radical production could be another mode of the action of essential oils on insects.

A revision of the Neotropical genus Chespiritos (Diptera: Sphaeroceridae: Limosininae)Original article

Gregory K. KUWAHARA, Stephen A. MARSHALL

Eur. J. Entomol. 117: 164-189, 2020 | DOI: 10.14411/eje.2020.019

The genus Chespiritos Marshall, 2000 (Diptera: Sphaeroceridae) is revised, including C. sindecimus Marshall, 2000, C. pervadens Roháček and Buck, 2003 and 19 new species. The following new species are described, keyed and placed in a morphological phylogeny: C. anguineus sp. n. from Bolivia, C. attenboroughi sp. n. from Argentina, C. balrogiformis sp. n. from Peru, C. bolanosi sp. n. from Mexico, C. calceus sp. n. from Peru, C. chicobrazos sp. n. from Costa Rica, C. coronatus sp. n. from Bolivia, Brazil, Colombia, Costa Rica, Ecuador and Trinidad, C. dolabratus sp. n. from Costa Rica, C. elephantus sp. n. from Ecuador and Peru, C. extendido sp. n. from Bolivia, Colombia, Costa Rica, Ecuador, Mexico, Panama and Venezuela, C. ganchopico sp. n. from Argentina, Bolivia, Ecuador, Panama and Tobago, C. gladiator sp. n. from Costa Rica, C. hojagrande sp. n. from Costa Rica and Mexico, C. jamaicensis sp. n. from Jamaica, C. lepustergum sp. n. from Costa Rica and Venezuela, C. metroidiformis sp. n. from Costa Rica, C. paraiso sp. n. from Dominican Republic, C. peckorum sp. n. from Ecuador, and C. ventrisetis sp. n. from Brazil, Costa Rica and Venezuela.

Insect photoperiodism: Seasonal development on a revolving planetReview

David SAUNDERS

Eur. J. Entomol. 117: 328-342, 2020 | DOI: 10.14411/eje.2020.038

This review starts by comparing photoperiodic diapause with non-photoperiodic quiescence in four representative species, paying particular attention to overwintering in Drosophila melanogaster. In the second part it describes dormancy strategies of insects from the equator to the polar regions, addressing topics such as the role of the circadian system in photoperiodic time measurement, latitudinal clines in diapause-related traits, hourglass-like photoperiodic clocks based on dampening circadian oscillators, and the dormancy strategies of insects close to the equator or at high latitudes where seasonal changes in photoperiod are unreliable or absent.

Mitochondrial DNA variation of Drosophila obscura (Diptera: Drosophilidae) across EuropeOriginal article

Pavle ERIĆ, Marina STAMENKOVIĆ-RADAK, Milan DRAGIĆEVIĆ, Maaria KANKARE, Megan A. WALLACE, Marija SAVIĆ VESELINOVIĆ, Mihailo JELIĆ

Eur. J. Entomol. 119: 99-110, 2022 | DOI: 10.14411/eje.2022.011

Drosophila obscura is a common fruit fly that inhabits the temperate forests of Europe. While it is abundant in the north compared to other Drosophila, its density decreases southwards, where it is gradually replaced by other Drosophila species. This study describes variation in the mitochondrial Cyt b gene of D. obscura from several European populations. We observed a large number of haplotypes, together with the structuring of genetic variation. Genetic variation is higher in the west where O1 and related divergent haplotypes dominate. In the east, the O2 haplotype is most frequent, together with haplotypes that recently arose from it. In the central part of the species range, both O1 and O2 are equally present, along with many others. These data reveal signs of population expansions that probably happened earlier in the west, and more recently in the east. Though our conclusions are based on only one genetic marker, limiting the power of the analysis, the results imply either postglacial expansion from two unique sources or, more likely, eastwards stepping-stone expansion. This study adds important information on genetic variation and phylogeography to the obscure biology of D. obscura, a species that has the potential to become an interesting model in evolutionary biology and conservation genetics.

Do egg parasitoids increase the tendency of Lestes sponsa (Odonata: Lestidae) to oviposit underwater?

Filip HARABIŠ, Aleš DOLNÝ, Jana HELEBRANDOVÁ, Tereza RUSKOVÁ

Eur. J. Entomol. 112 (1): 63-68, 2015 | DOI: 10.14411/eje.2015.017

The selection of oviposition sites by insects can significantly affect egg mortality. Spreadwing damselflies (Odonata: Lestidae) predominantly lay their eggs in parts of plants growing above the surface of water and only occasionally also those parts growing underwater. Factors affecting the choice of oviposition site and decision to lay underwater are still poorly understood. We examined whether localities with different risk of egg parasitism, different oviposition strategies (above or below the water surface) and the depth at which the eggs were laid, affected the total number of eggs laid, the proportion parasitized and egg mortality. In general, a significantly higher proportion of the eggs laid above the surface of water were parasitized but spreadwing damselflies showed significant preference for laying eggs underwater at both of the sites studied. This preference, however, had a different effect on the overall mortality of eggs at the two sites studied. Hence underwater oviposition by damselflies may be seen as a conditional anti-predator strategy, occurring only if the benefits exceed potential risks. Underwater oviposition may provide additional benefits other than protection against egg parasitism.

Cold and freezing injury in insects: An overview of molecular mechanismsIvo Hodek special issueReview

Jan ROZSYPAL

Eur. J. Entomol. 119: 43-57, 2022 | DOI: 10.14411/eje.2022.005

The present review discusses the molecular mechanisms of injury caused by low temperatures and/or freezing. The review is intended mainly for insect environmental physiologists who focus on the effects of low temperatures. The review successively discusses (1) the effects of low temperatures on the structure and function of macromolecules; (2) the effects of freezing on cells and macromolecules and (3) the mechanisms of damage during thawing and post-thaw. The review shows that injury primarily occurs at the molecular level in terms of damage to proteins, nucleic acids and biological membranes. The damage to macromolecular structures occurs as a result of the interaction between the effects of temperature, ice formation and resulting secondary effects such as osmotic stress, increased concentration of solutes, cellular freeze dehydration, disruption of ionic balance and oxidative stress. The present review attempts to identify gaps in our knowledge on the mechanisms of cold injury in organisms and proposes possible future directions that could contribute to filling the gaps.

Barrier pitfall traps increase captures of ground beetles (Coleoptera: Carabidae) on exposed riverine sedimentsOriginal article

Scott HORN

Eur. J. Entomol. 117: 76-82, 2020 | DOI: 10.14411/eje.2020.008

Exposed riverine sediments are unique riparian environments that exhibit high biodiversity and harbor many specialist species. Ground beetles are the most well studied inhabitants within these environments where they are often sampled using pitfall traps. In order to develop conservation measures for species occupying these habitats a logical first step is to refine sampling methods so that proper biodiversity assessments can be carried out. To that end, the effectiveness of two pitfall trap designs (standard trap vs. barrier trap) was evaluated. Over three sampling periods we collected 5,186 individuals represented by 43 species. Barrier traps proved to be superior, yielding significantly greater numbers of individuals (n = 3,456 vs. 1,730) than standard traps. Additionally, we collected more ground beetle species (37 vs. 30) in barrier traps than in standard pitfall traps. This study supports the rationale for deployment of more than one trap design to avoid deficiencies exhibited by a single type.

Taxonomic revision of the highly threatened Eumerus tricolor species group (Diptera: Syrphidae) in Southeast Europe, with insights into the conservation of the genus EumerusOriginal article

Ana GRKOVIĆ, Jeroen VAN STEENIS, Marija MILIČIĆ, Nataša KOČIŠ TUBIĆ, Mihajla DJAN, Snežana RADENKOVIĆ, Ante VUJIĆ

Eur. J. Entomol. 118: 368-393, 2021 | DOI: 10.14411/eje.2021.039

The diversity in the Eumerus tricolor group, the largest group within the genus in Southeast Europe, is investigated. Two new, locally distributed species are described, E. crispus Vujić & Grković, sp. n. from Serbia and E. nigrorufus Grković & Vujić, sp. n. from Montenegro. In addition to Southeast European members, one related species E. arctus van Steenis, sp. n. is described from Switzerland. We designate lectotypes for E. ovatus Loew, 1848, E. tarsalis Loew, 1848, E. tricolor (Fabricius, 1798) and E. varius Meigen, 1822. A map of the distribution of members of the E. tricolor group in Southeast Europe is provided. In addition, records from other parts of Europe are listed and an illustrated identification key to the SE European species of the E. tricolor group provided. We also study and discuss the significance of small habitat patches for the preservation of species of Eumerus, because the three species described in this paper are currently known from such patches.

Classification and characterization of immune haemocytes in the larvae of the Indian fritillary, Papilio hyperbius (Lepidoptera: Nymphalidae)Original article

Min-Soo GO, Youngwoo CHO, Ki-Byung PARK, Mijeong KIM, Sung Su PARK, Jangwoo PARK, Saeyoull CHO

Eur. J. Entomol. 119: 430-438, 2022 | DOI: 10.14411/eje.2022.045

In this study, haemocytes present in Papilio hyperbius Linnaeus were identified and characterized. Six different types of haemocyte were recorded in the haemocoel of this species of insect: prohaemocytes, plasmatocytes, granulocytes, spherulocytes, adipohaemocytes and oenocytoids. Of these the granulocytes were found to be responsible for cell-mediated immune responses such as phagocytosis. Granulocytes that were exposed to immunity inducers (carboxylate-modified polystyrene latex beads [CLBs] and Escherichia coli) had fan-like or pod-like structures on their cell membranes. The lysosomes in granulocytes were activated 2 h after injection with E. coli and after 12 h, all granulocytes exhibited highly activated lysosomes. After 24 and 48 h, the lysosome activity in granulocytes decreased. Transmission electron microscopy revealed that phagocytosis, which was mediated by granulocytes in the early hours of the E. coli infection, led to the formation of one phagosome for one E. coli within the cytosol. Moreover, as time passed, endosomes or lysosomes of different size developed. Subsequently, the phagosomes and lysosomes fused and E. coli were eliminated. After this series of immune responses, the nuclei of the granulocytes were indistinct and their cellular activity decreased. Hence, as old immune cells were replaced by new ones, active and healthy immune haemocytes were presumed to be maintained in the hemocoel.

Motorway as a barrier to dispersal of the threatened dragonfly Sympetrum depressiusculum (Odonata: Libellulidae): Consequence of mortality or crossing avoidance?Original article

Hana ŠIGUTOVÁ, Filip HARABIŠ, Michal HYKEL, Aleš DOLNÝ

Eur. J. Entomol. 114: 391-399, 2017 | DOI: 10.14411/eje.2017.050

Infrastructure is one of the main causes of landscape fragmentation, which results in isolation and loss of populations. Although the negative effect of roads on insects is well documented, only a minority of studies has focused on roads in the context of barriers to dispersal. Flying species in particular have been neglected. We investigated the effect of a four-lane motorway as a barrier to the movement of an isolated population of the threatened dragonfly Sympetrum depressiusculum in an agricultural landscape in Central Europe. Generalized additive models were used to assess the motorway's effect on (i) the distribution of adult dragonflies in patches of terrestrial habitat surrounding their natal site, and (ii) individual flight behaviour (i.e. willingness or unwillingness to cross the motorway). Movement patterns of marked adults throughout the landscape were also investigated. During one season, significantly fewer adults were found at patches located on the far side of the motorway, indicating it has a barrier effect. Observations on flight behaviour revealed no apparent effect of the motorway. The possible barrier effect for the species studied was therefore presumed to be a consequence of road mortality. Our results indicate that the motorway may influence the dispersal of this threatened species of dragonfly, which is a habitat specialist with particular requirements for its terrestrial environment. Negative effects on other species with similar behaviour and strategy can be presumed. When establishing new habitats, carrying out reintroductions or translocations, it is necessary to consider that roadways may reduce population size and affect population dynamics by limiting dispersal.

Daily survival and dispersal of adult Rhagonycha fulva (Coleoptera: Cantharidae) in a wooded agricultural landscapeOriginal article

Laura E. RODWELL, Jennifer J. DAY, Christopher W. FOSTER, Graham J. HOLLOWAY

Eur. J. Entomol. 115: 432-436, 2018 | DOI: 10.14411/eje.2018.043

Studies of insect population under field conditions to establish survival rates, longevity and dispersal rates are rare in the literature. These types of studies are important and can be used to inform studies of the effects of landscape composition and configuration on levels of biodiversity. Here the Cantharidae beetle, Rhagonycha fulva is studied under field conditions to derive estimates of daily survival rates for both males and females as well as local dispersal rates. Survival was studied at two sites, one in Wales and another in England, whilst dispersal was examined only at the Welsh site. Beetles were marked using different coloured enamel paints at the mid-point of a 200 m linear transect. The beetles were almost exclusively found (and marked) on common hogweed, Heracleum sphondylium. No difference in survival was found between males and females at both of the sites. The survival rates found at the two sites also did not differ. The overall daily survival rate was 0.771 equating with a median longevity of 4.37 days. Casual observations yielded a small number of marked individuals in excess of 400 m away from the point of marking. Movement of males along the transect differed from females. Marked females were never found far from the point of marking whilst males moved further away with time. This difference in behaviour is discussed in terms of hypothesized insect dispersal behaviour following emergence as mobile adults.

Phenotypic diversity in red wood ants (Hymenoptera: Formicidae): Is kinship involved?Original article

Oksana SKALDINA, Jouni SORVARI

Eur. J. Entomol. 117: 27-33, 2020 | DOI: 10.14411/eje.2020.003

Phenotypic diversity depends on genotype diversity, but the degree of genotype-by-environment interaction is species-specific. Red wood ants (Formica s. str) are keystone species in boreal forests and very variable phenotypically. These variations are used for species identification and proposed as ecological indicators of anthropogenic disturbances. However, their origin is unknown. Here we aimed to provide a preliminary answer to this question and outline the direction for future research. We determined the interrelation between nest mate worker relatedness (kinship) and the diversity of colour morphs, degree of melanisation and size of the red wood ant, Formica rufa. In Finnish populations of this species polyandry, which involves multiple mating by queens is the principal determinant of the relatedness between workers. We hypothesised, that if phenotypic diversity is a result of genetic diversity, then polyandrous colonies should produce more phenotypically diverse workers. A total of 336 individuals belonging to 20 colonies were used for this study. We collected ants from coniferous and broadleaf forests in Finland, fixed them in 96% alcohol, then digitally photographed, genotyped and analysed the phenotypic variation. The average colony nest mate worker relatedness was used as an estimate of the level of polyandry (more than one if r < 0.6). Our results revealed no associations between the diversity of the phenotypic traits measured and worker kinship in F. rufa. As a further step to reveal the degree of genotype-by-environment interaction in determining the colour traits of the red wood ant we suggest more sophisticated genetic studies indicating the heritability of phenotypic traits between patrilinies and testing of environmental factors such as temperature, humidity, UV-radiation, food and pollution.

Mitochondrial genomes of two wild silkmoths, Samia watsoni and Samia wangi (Lepidoptera: Saturniidae), and their phylogenetic implicationsOriginal article

Decai LU, Yixin HUANG, Stefan NAUMANN, Ian J. KITCHING, Zhenbang XU, Yang SUN, Xu WANG

Eur. J. Entomol. 119: 337-353, 2022 | DOI: 10.14411/eje.2022.035

The wild silkmoth genus Samia Hübner, 1819 (Saturniidae) contains a number of economically important species in industrial silk production. However, the interspecific relationships within the genus remain unclear. We sequence the mitogenomes of Samia watsoni Oberthür, 1914 and Samia wangi Naumann & Peigler, 2001. Both mitogenomes are annotated and found to be cyclized, with 37 genes (13 PCGs, 2 rRNA genes and 22 tRNA genes). Using maximum likelihood and Bayesian inference methods, we analyze these mitogenomes together with a further 68 downloaded from GenBank (65 Bombycoidea and 5 Lasiocampidae as the outgroup) to investigate the phylogenetic relationships both within the genus and those among the three families of the 'SBS' group: Bombycidae, Saturniidae and Sphingidae. The results show that within Samia, S. ricini is closely related to S. canningi, and not S. cynthia of which it has previously been considered to be a subspecies. Although arguments have been proposed to treat S. ricini and S. canningi as conspecific, we choose to accept the morphological arguments and continue to treat them as two separate species. Samia watsoni is corroborated as the sister group of all other Samia species, but nevertheless should be included within Samia rather than being placed in its own monobasic genus. Our analysis recovers the following relationship among the three families of the 'SBS' group: (Saturniidae + (Bombycidae + Sphingidae)). This agrees with previous studies based on analysis of mitogenomes but continues to contradict the results derived from phylogenomic analysis of nuclear genomes.

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