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Results 151 to 180 of 825:

Feeding and oviposition behaviour of a gall inducing species of Glycaspis (Synglycaspis) (Hemiptera: Psylloidea: Aphalaridae) and development of galls on the leaves of Eucalyptus macrorhyncha (Myrtaceae) in central western New South Wales, Australia

Anamika SHARMA, Anantanarayanan RAMAN, Gary S. TAYLOR, Murray J. FLETCHER, Helen I. NICOL

Eur. J. Entomol. 112 (1): 75-90, 2015 | DOI: 10.14411/eje.2015.021

Glycaspis (Synglycaspis) confined to Australia includes gall-inducing and lerp-forming species that are probably highly specific to different species of Eucalyptus subgenus Eucalyptus. Based on available information, their distribution appears restricted to temperate, south-eastern and southern Australia. This paper reports the biology of an unnamed (suspected new species) of Glycaspis (Synglycaspis) that induces spherical, ostiolate galls on the leaves of Eucalyptus macrorhyncha in central western tablelands of NSW. This species completes two generations in a year. Oviposition elicits a passive response in the leaves of E. macrorhyncha. In this work we demonstrate that the host tissue not only supplies water, but also nutrients to the developing embryo via the embedded pedicel. Feeding action of the first instar initiates the gall and morphogenetic gradients become apparent around the feeding site. These gradients direct gall growth. The gall attains its near final spherical shape during the second instar and this spherical gall remains plugged with sugary material, which all the immature stages secrete from the last abdominal segment. No significant gall growth occurs during the occupation of the gall by the third, fourth and fifth instars. The first and second instars feed on the newly differentiated parenchyma tissue in galls, whereas the third, fourth and fifth instars feed on phloem of galls. Consequently the multi-layer parenchymatous nutritive tissue that initially develops lining the chamber dries and shrivels, when the later instars inhabit galls. This shrinkage induces a gradual thinning of gall walls, which is also aggravated by modest expansive growth of the gall.

Evidence of forage distance limitations for small bees (Hymenoptera: Apidae)

Ivan R. WRIGHT, Stuart P.M. ROBERTS, Bonnie E. COLLINS

Eur. J. Entomol. 112 (2): 303-310, 2015 | DOI: 10.14411/eje.2015.028

The distribution of ground-nesting bees was investigated using transects of water traps in a mosaic of nesting and forage habitats at Shotover Hill in Oxfordshire, UK. The site includes a large area of ground-nesting bee activity and is adjoined on three sides by floristic hay meadows. This study showed that the females of small bee species (< 1.5 mm intertegular span) that were foraging in the hay meadows demonstrated a functional limitation to their homing range. The abundance of small bees declined rapidly with increasing distance from areas of high density nesting; declining more rapidly than might be expected from uniform dispersal into the surrounding landscape. By modelling the occurrence of bees along each transect it was found that the probability of observing a small bee in the hay meadows was reduced to 10% at a distance of 250-370 m from the nesting habitat. The result emphasises the scale on which habitat fragmentation will begin to impact upon bee diversity, and the relative contribution of managed "pollen and nectar" strips to areas of nesting habitat.

Is the type of soil an important factor determining the local abundance of carrion beetles (Coleoptera: Silphidae)?

Pavel JAKUBEC, Jan RÙ®IÈKA

Eur. J. Entomol. 112 (4): 747-754, 2015 | DOI: 10.14411/eje.2015.071

Carrion beetles (Coleoptera: Silphidae) provide a valuable ecosystem service by promoting nutrient cycling and controlling pests like noxious flies (Diptera: Calliphoridae and Sarcophagidae). Our main goal was to examine the relationship between the occurrence of carrion beetles and soil type. We used pitfall traps to collect 43,856 specimens of 15 species of carrion beetles in the Czech Republic during 2009. We found that the abundance of seven of the carrion beetles - Nicrophorus antennatus (Reitter), N. germanicus (Linnaeus), N. humator (Gleditsch), N. interruptus (Stephens), N. sepultor (Charpentier), Silpha obscura obscura (Herbst) and T. sinuatus (Fabricius) - was significantly higher either in areas with chernozem or fluvisol soils. These findings support our hypothesis that soil type could be an important factor determining the occurrence of necrophagous European carrion beetles. Our findings could be helpful when selecting important nature conservation sites (particularly inasmuch as N. antennatus, N. germanicus and N. sepultor are listed as endangered species on the Czech Red List of Invertebrates) as in this respect localities where there are chernozem soils are potentially valuable.

Assessment of the quality of the terrestrial habitat of the threatened dragonfly, Sympetrum depressiusculum (Odonata: Libellulidae)Original article

Michal HYKEL, Filip HARABI©, Ale¹ DOLNÝ

Eur. J. Entomol. 113: 476-481, 2016 | DOI: 10.14411/eje.2016.062

The majority of the conservation strategies for threatened dragonflies are designed to protect only their aquatic habitats. Sympetrum depressiusculum is a species threatened not only by the destruction of its aquatic habitats but also by its association with a specific terrestrial environment. In this study, we aimed to identify the key elements of the terrestrial environment of adult S. depressiusculum. We used generalized linear mixed models to determine habitat preferences of adults and the particular features of habitat patches, such as vegetation cover, vegetation structure and the availability of potential prey. Our results indicate that S. depressiusculum adults preferred mainly riparian vegetation but beyond ponds they utilized only certain terrestrial habitats (abandoned fields, meadows, forest clearings). Adults responded positively to habitat patches with a high cover of vegetation and suitable vegetation structure. Adult abundance was affected also by the distance of patches from the natal site. In an agricultural landscape, the availability of such habitat patches may be limited and could influence the abundance and distribution of this species. We suggest that conservation efforts for this species should not only focus on the larval environment but also include suitable surrounding terrestrial habitats. Effective management around natal sites should concentrate on maintaining a heterogeneous landscape, which is extensively managed (e.g. leaving several fields fallow, maintaining managed hay meadows).

The effects of oviposition site on the development of the wood borer Coraebus florentinus (Coleoptera: Buprestidae)

Ana M. CÁRDENAS, Patricia GALLARDO

Eur. J. Entomol. 110 (1): 135-144, 2013 | DOI: 10.14411/eje.2013.019

Coraebus florentinus (Herbst) is one of the most important wood borer pests of oaks in forest ecosystems in the Mediterranean Region. It is considered to be a heliophilous species as it prefers the sunniest parts of the canopy of isolated trees. The biological significance of this preference is still unknown. Recently, the effect of temperature on the preimaginal development of this insect was established: high temperatures increase its probability of survival and shorten its developmental time. Continuing this line of research, this study was designed to determine whether C. florentinus exhibits selective oviposition behaviour and how variation in temperature due to differences in the position of the branches in which the larvae develop could affect the subsequent development of this species. To determine whether this insect selects the branches in which to lay its eggs, location data (north, south, upper half and lower half of the tops of the trees) for 112 damaged branches were analysed. The results confirm that females of C. florentinus do not lay their eggs at random at the tops of trees but rather choose branches that are exposed to the sun. To determine the effects of larval rearing temperature on the later development stages, an experiment consisting of five treatments was performed. Four of these treatments, each containing 25 infested branches derived from different orientations and positions in a tree (upper half of tree and north facing, upper half and south facing, lower half and north facing and lower half and south facing) were kept in culture chambers maintained at optimal conditions for pupal development (28 ± 2°C and 60-65% relative humidity). The fifth treatment with 25 branches infested collected from the most sun-exposed locations were kept in outdoor conditions. The results indicate that variation in temperature during larval development due to differences in branch location does not significantly affect survival, duration of developmental of pupae, emergence success or sex ratio of the adults.

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.

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.

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.

An overview of irritans-mariner transposons in two Mayetiola species (Diptera: Cecidomyiidae)Original article

Wiem BEN AMARA, Salma DJEBBI, Dhia BOUKTILA, Mohamed MAKNI, Hanem MAKNI, Maha MEZGHANI-KHEMAKHEM

Eur. J. Entomol. 114: 379-390, 2017 | DOI: 10.14411/eje.2017.049

Mariner-like elements (MLEs) are widespread Class II transposable elements in insects that are subdivided into several subfamilies. In the current study, we carried out in silico analysis and in vitro experiments to identify MLEs belonging to the irritans subfamily in two cecidomyiid flies, Mayetiola destructor and M. hordei. In silico investigation of M. destructor genome allowed the identification of 25 irritans-like elements, which were mostly defective due to several mutations. These defective forms might be the remnants of active elements that ancestrally invaded the host genome. Structural analyses, including signature motifs and transposase-encoding ORFs, revealed structural heterogeneity and the presence of two full length copies. Five consensuses, reflecting the probable evolutionary groups of these elements, were constructed, based on a similarity matrix. The first consensus (Maymarcons1) belonged to Himar1-like elements reported in other insects, while the remaining four (Maymarcons2 to 5) seemed to be more specific to Cecidomyiidae. Moreover, the presence of elements belonging to the Maymarcons4 group was ascertained by PCR amplification, in both Mayetiola species, and was further identified in the Transcriptome Shotgun Assembly (TSA) of the orange fly, Sitodiplosis mosellana (Cecidomyiidae), suggesting the existence of irritans elements within the Cecidomyiidae, which were derived from an ancestral species by vertical transmission during speciation. On the other hand, consensuses that are specific to M. destructor could be derived from a more recent invasion. This study suggests that both M. destructor and M. hordei genomes have been invaded by irritans elements many times with at least two different evolutionary histories.

Associations between canopy openness, butterfly resources, butterfly richness and abundance along forest trails in planted and natural forestsOriginal article

Atsushi OHWAKI, Saki MAEDA, Masahiko KITAHARA, Takashi NAKANO

Eur. J. Entomol. 114: 533-545, 2017 | DOI: 10.14411/eje.2017.068

Increasing the biodiversity in plantations of trees is an important issue because plantations have replaced many natural and semi-natural ecosystems worldwide. Therefore, identifying appropriate management techniques and key factors for enhancing biodiversity in plantations is required. We surveyed butterfly assemblages along forest trails in both plantations and natural forests and measured various environmental variables, including canopy, sub canopy and shrub stem densities, percentage of deciduous trees, flower plant richness, host plant richness, canopy openness and distance to forest edge. We hypothesized that (1) flower and host plant richness increase with an increase in the percentage of deciduous trees and canopy openness; (2) butterfly richness and abundance increase with an increase in forest structural complexity, butterfly resources, canopy openness and distance to forest edge; (3) the responses of plants and butterflies to canopy openness differ in plantations and natural forests; and (4) in plantations, tree-feeding butterflies respond to canopy openness less strongly than herbaceous plant feeding butterflies do because of the low diversity of trees in plantations. Our results generally support these hypotheses. Butterfly resources and butterfly richness and abundance all increase with increasing canopy openness; however, the increases were usually more dramatic in natural forests than in plantations and other factors are less important. In plantations, herbaceous plant feeding butterflies responded to increasing canopy openness more strongly than tree-feeding butterflies. The results of the present study indicate the importance of sunlit forest trails in enhancing butterfly resources, butterfly richness and abundance in plantations. Because at the stand-level management is labour- and cost-intensive, labour- and cost-saving trail management options need to be explored further in terms their effectiveness in increasing biodiversity in plantations.

Detailed morphological descriptions of the immature stages of the ant parasite Microdon mutabilis (Diptera: Syrphidae: Microdontinae) and a discussion of its functional morphology, behaviour and host specificityOriginal article

Giulia SCARPARO, Pierfilippo CERRETTI, Maurizio MEI, Andrea DI GIULIO

Eur. J. Entomol. 114: 565-586, 2017 | DOI: 10.14411/eje.2017.071

The myrmecophilous immature stages of hover flies of the genus Microdon Meigen, 1803 (Diptera, Syrphidae) are still poorly known and only about 15 species were previously incompletely described and/or illustrated using light microscopy based on occasional findings mainly of pupae and third instar larvae. The exceptional finding of a large number of second and third instar larvae and pupae (159 specimens) of Microdon mutabilis (Linnaeus, 1758) inside the nest of a new host species, Formica cunicularia Latreille,1798, enabled us to rear them and obtain a great number of eggs and first instar larvae. We filmed and described the feeding behaviour and locomotion of these highly derived slug-like larvae. Combining light, fluorescence and scanning electron (SEM) microscopy, we describe in detail and illustrate the external features of all the immature stages of M. mutabilis (eggs, larvae and pupae). Covering the entire chorion of the egg is a peculiar microsculpture composed of volcano-like processes. The three larval instars strongly differ from each other, especially at the level of the shape of the body, the posterior spiracular tubercle and the cephaloskeleton. SEM microscopy was used to describe in detail the microsculpture, sensorial structures, spiracles and cephalic appendages of larvae and pupae. Fluorescence microscopy was used to reveal the exceptional presence of resilin in the external layer of the posterior spiracular tubercle in first instar larvae. The possible functional significance of these structures is discussed.

Efficiency of pitfall traps with funnels and/or roofs in capturing ground-dwelling arthropodsOriginal article

Péter CSÁSZÁR, Attila TORMA, Nikolett GALLÉ-SZPISJAK, Csaba TÖLGYESI, Róbert GALLÉ

Eur. J. Entomol. 115: 15-24, 2018 | DOI: 10.14411/eje.2018.003

Pitfall traps are widely used for sampling ground-dwelling arthropods. Their sampling efficiency is affected by several factors, e.g. material, size and modification of parts of the trap and sampling design. Pitfall trap sampling is also affected by the accumulation of plant litter in the traps, rain fall and by-catches of small vertebrates, which may cause a bias in the catch by obstructing traps or attracting certain insects. A roof that prevents rain and plant litter entering a trap, prevents dilution of the preservative and escape of arthropods. The main goal of present study was to compare the effect of four types of differently combined funnel and roof pitfall traps on the capture efficiency of epigeal arthropods. We found that a funnel and/or a roof had no effect on spider catches. Total abundance of large carabids and thus the total abundance of ground beetles was lower in funnel pitfall traps without a roof than in other types of traps. However, funnel pitfall traps with roofs collected significantly more carabid beetles, especially individuals of those species that are large or good fliers. We conclude that funnel pitfall traps with roofs have no negative effects on capture efficiency of ground beetles and spiders, therefore application of this sampling technique is strongly recommended.

Cold hardiness of larvae of Dendrolimus tabulaeformis (Lepidoptera: Lasiocampidae) at different stages during the overwintering periodOriginal article

Yuying SHAO, Yuqian FENG, Bin TIAN, Tao WANG, Yinghao HE, Shixiang ZONG

Eur. J. Entomol. 115: 198-207, 2018 | DOI: 10.14411/eje.2018.018

The Chinese pine caterpillar Dendrolimus tabulaeformis is an important destructive leaf borer in boreal coniferous forests in China. This species overwinters in the larval stage. Changes in supercooling capacity and physiological-biochemical parameters of D. tabulaeformis larvae from a natural population were evaluated at different stages during the overwintering period. Cold hardiness of overwintering larvae collected in January was significantly greater than that of larvae collected in other months. January larvae survived for 15 days at -10°C and for approximately 2 days at -15°C. By contrast, larvae collected in September survived for no more than 4 h at -5°C and those in November and March no more than 1 day at -15°C. Supercooling point gradually decreased from -5.9 ± 0.3°C in September to a minimum of -14.1 ± 1.0°C in November, then gradually increased to the original value with the advent of spring. Water content gradually decreased from September to November, remained at approximately 74.5% until March and then gradually increased to levels similar to those in September. The lipid content gradually decreased from September to November, remained stable at approximately 3.2% until March and then gradually increased to levels similar to those in September. Glycogen content increased to a peak in November and then decreased. The concentrations of several metabolites showed significant seasonal changes. The most prominent metabolite was trehalose with a seasonal maximum in November. Glucose levels were highest in January and then gradually decreased until in May they were at levels similar to those in September. Glycerol levels remained relatively stable during winter but increased significantly in May. This study indicates that D. tabulaeformis is a freeze-avoidant insect. Larvae increase their supercooling capacity by regulating physiological-biochemical parameters during overwintering. Our results provide the basis for further research into the mechanism of cold hardiness in this species.

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.

One step closer to understanding the ecology of Cameraria ohridella (Lepidoptera: Gracillariidae): The effects of light conditionsOriginal article

Rados³aw JAGIE££O, Edward BARANIAK, Marzenna GUZICKA, Piotr KAROLEWSKI, Adrian £UKOWSKI, Marian Jêdrzej GIERTYCH

Eur. J. Entomol. 116: 42-51, 2019 | DOI: 10.14411/eje.2019.005

Horse chestnut leaf miner (Cameraria ohridella) has achieved ecological success by colonizing the entire European range of its primary host, horse chestnut (Aesculus hippocastanum). This insect has attracted the attention of scientists, but its ecology is poorly understood. Here, we investigated the effects of varying degrees of light availability on the leaf morphology of horse chestnut saplings and the performance of C. ohridella. A pot experiment under greenhouse conditions was performed in which the photosynthetic photon flux density (PPFD) was reduced from full light by 50% (high light - HL) or 80% (low light - LL). Insect performance parameters were quantified (i.e., pupal mass, efficiency of conversion of utilised leaf tissue (ECU) and potential fecundity). Compared with HL leaflets those from LL were characterised by higher contents of nitrogen and water but lower total phenolics. The oxidative capacity of phenolics (at pH ≈ 10, common in the lepidopteran gut) was low and did not differ in the two treatments. Compared with those collected from HL leaves, the mines of those collected from leaves of plants grown under LL conditions were larger in area but the leaf mass utilized by larvae was similar. Pupae were heavier in LL than in HL conditions, and ECU was higher in LL. The potential fecundity of females was not sensitive for experimental treatment. We conclude that (1) reduced light had a strong beneficial effect on the performance of C. ohridella and (2) phenolics in A. hippocastanum leaf tissues are a poor defence against this herbivore.

Factors determining local and seasonal variation in abundance of Harmonia axyridis (Coleoptera: Coccinellidae) in Central EuropeOriginal article

Alois HONÌK, Marek BRABEC, Zdenka MARTINKOVÁ, Anthony F.G. DIXON, Stano PEKÁR, Jiøí SKUHROVEC

Eur. J. Entomol. 116: 93-103, 2019 | DOI: 10.14411/eje.2019.011

To determine the causes of the variation in the seasonal dynamics of Harmonia axyridis (Pallas) in Central Europe, numbers of adults and larvae of this invasive species were recorded on trees (Acer, Betula, Tilia) throughout the growing seasons from 2011 to 2016. Each year beetles were collected every two weeks, using a standardized sweeping method. The seasonal dynamics was expressed as plots of abundance (number of individuals per 100 sweeps) against time (Julian day) and these plots (seasonal profiles) were compared in terms of their size (area under the seasonal profile curve), range, timing and height of the mode (maximum abundance). Timing and size of seasonal profiles varied among hostplants, years and sites. Abundance of larvae paralleled aphid occurrence and peak abundance of adults followed that of larvae 10 to 20 days later. Population dynamics before and after the peak were determined by dispersal. Adults arrived at sites before the start of aphid population growth and persisted there long after aphid populations collapsed. The abundance of H. axyridis decreased from 2011 to 2013 and then increased, achieving the previous levels recorded in 2015 and 2016. The variation in seasonal profiles revealed that H. axyridis, in terms of its response to environmental conditions, is a plastic species and this flexibility is an important factor in its invasive success.

Daily rhythmicity in the sexual behaviour of Monema flavescens (Lepidoptera: Limacodidae)Original article

Shuzhen YANG, Hongxia LIU, Meihong YANG, Jintong ZHANG

Eur. J. Entomol. 116: 104-108, 2019 | DOI: 10.14411/eje.2019.012

Daily rhythmicity in the sexual behaviour of Monema flavescens Walker (Lepidoptera: Limacodidae) was studied under laboratory conditions. There was a distinct diel periodicity in female calling, male responsiveness and mating behaviour of M. flavescens. As females aged there was an advance in the onset and more time spent calling. One day old females started calling 4 h after the onset of the scotophase, and 5 to 6 day old females called during the first hour of the scotophase. About 34.5% of females called on the night they emerged (1 day old) and the peak in calling of 97.8% was recorded for 2 day old females, after which the incidence of calling decreased rapidly with advancing age. Wind tunnel and copulation tests showed that males were sexually mature on the third night and female moths on the second night. The highest value for the percentage mating was recorded for 3 day old virgin females 4 to 6 h after the onset of the scotophase. In field tests, traps baited with 2 day and 3 day old virgin females captured more males than any other trap and most males were captured 4 to 6 h (1 to 2 day old), 3 to 5 h (3 to 4 day old) and 2 to 4 h (5 to 6 day old) after the onset of the scotophase. These results indicate that there is a daily rhythm in the reproductive behaviour of M. flavescens and provides a better understanding of its sexual behaviour.

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 role of iron (Fe) in the population dynamics of pistachio psyllid, Agonoscena pistaciae (Hemiptera: Aphalaridae) in Pistacia orchardsOriginal article

Hossein DEHGHANI-YAKHDANI, Shahzad IRANIPOUR, Mohammad Reza MEHRNEJAD, Reza FARSHBAF-POURABAD

Eur. J. Entomol. 116: 194-200, 2019 | DOI: 10.14411/eje.2019.021

The common pistachio psyllid (CPP) is thought to respond to nutrient availability in pistachio trees. We determined the effect of a deficiency of leaf iron (Fe) has on the abundance of the pistachio psyllid at a regional scale. First, we monitored the abundance pistachio psyllid in four pistachio orchards (24 trees as 24 repetitions) located in Maybod County, Yazd province in the centre of Iran and then measured leaf nutrient levels. Orchards were located up to 2.6 km apart. Multivariate regressions were used to determine the relationship between leaf nutrients and CPP population growth. The results indicate that the number of psyllid eggs and population growth rate of the nymphs was negatively correlated with Fe levels in the leaves, while peak numbers of psyllid eggs were positively correlated with the levels of Cu in the leaves. In a manipulative field experiment, we conducted two experiments: (1) pistachio trees treated with iron compared with control trees, and (2) pistachio trees previously treated with iron were treated with ammonium sulphate and compared with trees treated with ammonium sulphate. In the first experiment, psyllids in leaf disc-cages had a significantly greater intrinsic rate of population increase and net reproductive rate on Fe-treated trees than the control trees (Stage 1). In the second experiment, psyllids in leaf disc-cages had similar intrinsic rates of population increase and net reproduction both on the ammonium sulphate treated trees (control) and those previously treated with iron. This indicates that iron may have reacted negatively with nitrogen content of the leaves. In general, these findings indicate that when there is a deficiency of iron in the leaves, the application of nitrogen fertilizer had little effect on the performance of CPP and may have played a minor role in the population dynamics of CPP, but the application of a Fe fertilizer without considering the nitrogen content of the leaves may lead to a population outbreak.

Host-based genetic divergence in populations of an exotic spiralling whitefly, Aleurodicus dispersus (Hemiptera: Aleyrodidae)Original article

Thangavel BOOPATHI, Subbarayalu MOHANKUMAR, GAYACHARAN, Manickavasagam Pillai KALYANASUNDARAM, Soibam Basanta SINGH, Ramaraju ARAVINDRAJ, Bangaru PREETHA, Kandasamy SANKARI MEENA, Kothandaraman CHANDRASEKAR

Eur. J. Entomol. 116: 221-228, 2019 | DOI: 10.14411/eje.2019.024

The morphology, physiology, behaviour and ecology of spiralling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae) on different host plants differ greatly. The genetic differences between the A. dispersus populations on 17 host plants were evaluated in the current study. Microsatellite markers were used to identify the presence of host-related genetic variation among A. dispersus populations. Our research clearly shows that there is a significant amount of genetic divergence among the A. dispersus populations on 17 host plants in India. The spiralling whitefly on acalypha and calotropis were genetically more distinct than whiteflies on other host plants. Various population genetic parameters, like heterozygosity, Nei's genetic distance, fixation indices (FST), source of genetic variation in AMOVA, etc. indicate that populations of spiralling whiteflies differ greatly genetically, probably because the spiralling whitefly populations on the Indian sub-continent came from multiple sources. The results of this study have implications for the quarantine protection strategy against this invasive pest.

Altitudinal gradient in species richness and composition of dung beetles (Coleoptera: Scarabaeidae) in an eastern Euro-Mediterranean locality: Functional, seasonal and habitat influencesOriginal article

Yakup ªENYÜZ, Jorge M. LOBO, Kemal DINDAR

Eur. J. Entomol. 116: 309-319, 2019 | DOI: 10.14411/eje.2019.034

The altitudinal gradient in diversity of dung beetles (Scarabaeidae) was studied in a Mediterranean mountain chain located in Central Anatolia to (i) determine if there are altitudinal differences between the main taxonomic groups, (ii) describe the seasonal variations in these assemblages and (iii) assess whether closed habitats influence dung beetle diversity differentially at different altitudes. Beetles were collected throughout a year at 14 localities between 469 and 1810 m above sea level in three different types of habitats. Dung beetle assemblages at 400 to 1200 m did not vary greatly in species richness, abundance and biomass. However, they varied in composition, with the assemblages dominated by species of Scarabaeinae up to 900 m, whereas in the mid-mountain assemblages (from 900 m to 1600 m) the numbers of species of Aphodiinae was higher. The decline with increase in altitude in richness, abundance and biomass of both small and large species of Scarabaeinae up to 1500 m, together with the constancy of these parameters in the case of Aphodiinae, accounts for the changes in the composition from the lowland to mid-mountain localities. Unlike at other Mediterranean localities, the open/closed structure of the habitat only slightly influences these assemblages independently of altitude or season. The general seasonal pattern follows the classical Mediterranean bimodal pattern associated with summer drought, but the patterns are more complex when the seasonal responses of the different groups and at different localities are analysed separately. We propose that the interplay between local climatic conditions (mainly temperature) and evolutionary conserved species preferences accounts for both the current seasonal and altitudinal gradients and the changes in species composition in terms of Aphodiinae and Scarabaeinae.

Pupal traits and adult emergence in the pine processionary moth Thaumetopoea pityocampa (Lepidoptera: Notodontidae) are affected by pupal densityOriginal article

Carmelo P. BONSIGNORE, Francesco MANTI, Elvira CASTIGLIONE, Andrea BATTISTI

Eur. J. Entomol. 116: 320-329, 2019 | DOI: 10.14411/eje.2019.035

The expectation is that the phenology of an herbivore is influenced by abiotic factors and its own population density during development. In this study, we investigated how the pupal density affected the pupal traits and emergence of Thaumetopoea pityocampa moths over a period of 3 years in two clearings in a pine forest. The pupae were larger in years when the pupal density was high and in the clearing exposed to less solar radiation. There was no relationship between the time of pupation and pupal size. Large pupae were positively correlated with an early emergence of adult moths and a longer period of adult emergence. Up to 13.9% of the pupae developed without cocoons, especially in years when they were abundant, but this did not affect the emergence of the moths. Incidence of pupal diapause was density-dependent and only occurred at a low level in dense populations. Overall, our results indicate that gregariousness confers important fitness-related advantages in this species.

Differences in the niches of keratin/chitin feeding moths (Lepidoptera: Tineidae) in bird nests in central JapanOriginal article

Hiroaki SATO, Yoshitsugu NASU, Shiro MURAHAMA, Hiroyuki MATSUMURO, Keisuke UEDA

Eur. J. Entomol. 116: 442-449, 2019 | DOI: 10.14411/eje.2019.045

Some moth larvae feed not on plants but on keratin and/or chitin produced by animals. These substances are polymers and are commonly found in bird nests as feathers and raptor pellets. Many qualitative studies have examined the association of keratin/chitin feeding moths with bird nests. However, few studies have quantified the species composition with respect to type of nest and habitat. Hence, we have studied the degree to which the niches of these moths differ in terms of type of nest and habitat. We set-up open-top nest boxes for the Ural owl Strix uralensis (damp exposed nests from which owl chicks were fledged successfully) and artificial bird nests (mesh bags filled with duck down to imitate dry exposed nests) in a deciduous forest and artificial bird nests in an urban setting in Aichi Prefecture, central Japan, and collected the contents of the nests every two months from June to December 2014. We recorded 592 individuals of five keratin/chitin feeding moth species (Tineidae, Tineinae) from the contents. Using non-metric multidimensional scaling and cluster analysis of the relative abundances of individual species in each type of nest in forest and urban settings, these species were classified into three groups: (1) Monopis longella and M. congestella inhabiting forest, (2) M. flavidorsalis and Niditinea tugurialis mainly in damp exposed nests in forest and (3) N. piercella mainly in dry exposed nests in urban areas. This classification was compared with findings of other studies. As a result, these moths probably have different niches with respect to nest type (damp or dry), keratin/chitin as a source of food (raptor pellets or feathers), and habitat (forest or urban area). Furthermore, we suggest that the evolution of larviparity in M. congestella might be related to its preference for feathers as a source of food for the development of its larvae.

The entomofauna on Eucalyptus in Israel: A reviewReview

Zvi MENDEL, Alex PROTASOV

Eur. J. Entomol. 116: 450-460, 2019 | DOI: 10.14411/eje.2019.046

The first successful Eucalyptus stands were planted in Israel in 1884. This tree genus, particularly E. camaldulensis, now covers approximately 11,000 ha and constitutes nearly 4% of all planted ornamental trees. Here we review and discuss the information available about indigenous and invasive species of insects that develop on Eucalyptus trees in Israel and the natural enemies of specific exotic insects of this tree. Sixty-two phytophagous species are recorded on this tree of which approximately 60% are indigenous. The largest group are the sap feeders, including both indigenous and invasive species, which are mostly found on irrigated trees, or in wetlands. The second largest group are wood feeders, polyphagous Coleoptera that form the dominant native group, developing in dying or dead wood. Most of the seventeen parasitoids associated with the ten invasive Eucalyptus-specific species were introduced as biocontrol agents in classical biological control projects. None of the polyphagous species recorded on Eucalyptus pose any threat to this tree. The most noxious invasive specific pests, the gall wasps (Eulophidae) and bronze bug (Thaumastocoris peregrinus), are well controlled by introduced parasitoids. Potential entomological hazards of Eucalyptus in Israel are most likely to originate from the Australian insect fauna.

Diversity of ant assemblages (Hymenoptera: Formicidae) in an urban environment in Cameroon during and after colonization of the area by Wasmannia auropunctataOriginal article

Paul Serge MBENOUN MASSE, Maurice TINDO, Champlain DJIÉTO-LORDON, Ruth MONY, Martin KENNE

Eur. J. Entomol. 116: 461-467, 2019 | DOI: 10.14411/eje.2019.047

Invasive species disrupt the organization and functioning of many ant communities. Little is known about ant assemblages formerly in areas invaded by the little fire ant. In this study, we surveyed the same areas and compared the ant communities there when an invasive species first colonized the areas and 10 years later, using the same methodology (quadrat and baiting). A total of 83,299 worker ants from 17 species or morphospecies, in 4 subfamilies and 10 genera were recorded in the two periods sampled. Seven ant species were found to co-occur with W. auropunctata while 12 species were collected in the same area 10 years later, with no W. auropunctata recorded in any of the traps. In the absence of W. auropunctata, the number and diversity of ant species increased and the ant communities were dominated by the African big-headed ant, Pheidole megacephala. Our findings indicate that the disappearance of W. auropunctata is probably related to population increases in P. megacephala associated with dramatic changes in landscape. Further studies at other invaded locations should be carried out in order to reveal the generality of these patterns throughout this country.

Sexual differences in the morphology and movement of a butterfly: Good shape does not make good dispersersOriginal article

Elisabeth REIM, Fee WIDDERICH, Klaus FISCHER

Eur. J. Entomol. 116: 468-476, 2019 | DOI: 10.14411/eje.2019.048

Movements are involved in several routine processes and may scale up to important ecological processes such as dispersal. However, movement is affected by a wealth of factors including flight capacity and behavioural traits. Both frequently differ in the sexes, which may well affect movement. We here aim to disentangle the relative importance of sexual differences in flight capacity versus behaviour on small-scale movements under controlled laboratory conditions in the temperate-zone butterfly Lycaena tityrus. The morphology of males is typically associated with increased flight capacity in this species. Nevertheless, the flight performances of the sexes did not differ, but the mobility of the females was higher. Thus, flight capacity and patterns of movement may not be intimately associated. Rather, the costs and benefits of flight seem to differ substantially between the sexes, with females being more mobile, potentially as a risk spreading strategy, while males are territorial and thus more sedentary. Thus, predictions regarding movement based on morphology are difficult.

Methods for retaining well-preserved DNA with dried specimens of insectsOriginal article

Naoyuki NAKAHAMA, Yuji ISAGI, Motomi ITO

Eur. J. Entomol. 116: 486-491, 2019 | DOI: 10.14411/eje.2019.050

Dried specimens of insects are increasingly seen as genetic resources. However, genetic analysis of dried specimens of insects is hampered by the deterioration of the DNA. In this study, we developed methods for preparing dried specimens of insects with well-preserved DNA, mainly for PCR-based genetic analysis. First, we compared the effects of either exposure to ethyl acetate vapour for from 10 min to 6 h or by freezing on the fragmentation of DNA in order to determine optimal length of time needed for killing insects using the above methods. Second, we compared the fragmentation of DNA after preservation by drying or immersion of legs in 99.5% ethanol or 99% propylene glycol in 0.2-ml tubes. We assessed degrees of fragmentation of DNA by determining polymerase chain reaction (PCR) success rates with primers for 313-, 710- and 1555-bp fragments using DNA that was collected immediately, and at one, six and 12 months after preparing the specimens. Differing times taken to kill insects did not affect the fragmentation of DNA. In dried specimens, DNA was seriously fragmented after one month, whereas that in legs prepared by immersion in 99.5% ethanol or 99% propylene glycol contained long fragments of DNA (1555 bp~) after 12 months. Propylene glycol was more suitable for preservation than ethanol, because the latter evaporates. Thus, to preserve insect DNA we suggest inserting the pin on which an insect is impaled into the hinged lid of a 0.2-ml tube containing 99% propylene glycol so that when the lid is closed the legs of the insect are preserved in the solution.

Local adaptation at fine spatial scale through chromosomal inversions and mito-nuclear epistasis: Findings in Drosophila subobscura (Diptera: Drosophilidae)Original article

Marija SAVIÆ VESELINOVIÆ, Zorana KURBALIJA NOVIÈIÆ, Bojan KENIG, Mihailo JELIÆ, Aleksandra PATENKOVIÆ, Marija TANASKOVIÆ, Cino PERTOLDI, Marina STAMENKOVIÆ-RADAK, Marko ANDJELKOVIÆ

Eur. J. Entomol. 116: 492-503, 2019 | DOI: 10.14411/eje.2019.051

To explore local adaptation in wild populations at a fine spatial scale we characterized the genetic variability of eight closely located populations of Drosophila subobscura and its associations with microhabitat environmental conditions. Three different genetic markers were assessed: chromosomal inversions, a SNP of mitochondrial ND5 gene and nuclear microsatellites. Population genetic analyses of chromosomal variability revealed significant genetic differentiation between these populations. Gene arrangement frequencies on the E chromosome contributed most to these differences. We also investigated role of mito-nuclear epistasis in mitochondrial genome differentiation and revealed weak linkage disequilibrium (LD) exclusively between O3+4 inversion arrangement and mitochondrial DNA haplotype I in two populations. In addition, the trend in the LD between OST chromosomal arrangement and haplotype II was general in the total sample. Microsatellite analysis revealed an absence of stochastic processes, like census reduction, upon population differentiation. Only a small amount of the genetic variation is related to geographic distance, while most (97%) is attributable to other factors and in some degree to microhabitat variables (temperature, humidity). The analysis of these factors revealed they effect inversion arrangement frequencies, especially E1+2+9, EST and OST. Even though this model organism is known for its high mobility and mostly large effective population size, the results presented here reveal that local adaptations can occur even at a small spatial scale. We propose that locally adapted alleles within chromosomal inversions, as well as joint selective pressures acting on mitochondrial and nuclear genomes, are responsible for the observed adaptation to microhabitat conditions.

Strategy for sneaking into a host's home: The cuckoo wasp Omalus biaccinctus (Hymenoptera: Chrysididae) inserts its eggs into living aphids that are the prey of its host

Patrick WINTERHAGEN

Eur. J. Entomol. 112 (3): 557-559, 2015 | DOI: 10.14411/eje.2015.064

Parasitic Hymenoptera usually need to have direct access to their host or its offspring or to be able to enter and place their offspring in a nest of their host, where their progeny develop at the expense of the host. In the case of the cleptoparasitic cuckoo wasps (Chrysididae) their main target is the nest of the host and they have various strategies for locating and entering their host's brood cells for ovipositing. The chrysidid Omalus biaccinctus (Buysson, 1893), a parasitoid of aphid hunting crabronid wasps, was observed apparently inserting its eggs into living aphids at the hunting site of their host and the presence of the parasitoid's egg and DNA in aphids after oviposition was confirmed. It is concluded that O. biaccinctus "hitch-hikes" into a host's brood cell concealed in the aphid prey collected by the host wasp and the adult parasites do not need to enter the nest of their host in order to lay their eggs.

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