The maritime pine bast scale, Matsucoccus feytaudi Ducasse (Hemiptera: Matsucoccidae), occurs in the western part of the Mediterranean basin and is a sap sucking insect that feeds only on maritime pine (Pinus pinaster Aiton). It causes damage in SE France and Italy, where it was accidentally introduced. In Spain information is scarce and, moreover, almost nothing is known about the predators of this species. This study was designed to determine the seasonal trends in abundance of M. feytaudi and its major predators, which might help to improve the biological control of this pest in other areas. Natural P. pinaster stands in the Valencian Community (Spain) were surveyed in 2004. In addition, the seasonal trends in abundance of M. feytaudi and its natural enemies were monitored in three stands over a period of three years (2002, 2005 and 2006). The monitoring was carried by wrapping sticky tapes around tree trunks and using delta traps baited with sexual pheromone. The maritime pine bast scale was detected in all the stands surveyed. At almost all the sites surveyed, three species of predators were captured: Elatophilus nigricornis Zetterstedt (Hemiptera: Anthocoridae), Hemerobius stigma Stephens (Neuroptera: Hemerobiidae) and Malachiomimus pectinatus (Kiesenwetter) (Coleoptera: Malachiidae). The presence of M. pectinatus is noteworthy as this is the first record of this species as a possible predator of M. feytaudi. The results show that M. feytaudi, although differing in its phenology depending on the location, is univoltine in the study area. The prepupae, pupae and adults of M. feytaudi appeared between December and March in colder areas and between October and February in warmer areas. E. nigricornis nymphs are important predators of M. feytaudi, and were abundant when the scale insect (crawlers, prepupae, pupae, male and female adults) was present. The flight period of E. nigricornis and the hemerobiid H. stigma ranged from May to October. However, these flight patterns did not correlate with the presence of the different stages of the bast scale (crawlers, prepupae, pupae, male and female adults) on the surface of tree trunks. The presence of M. pectinatus in large numbers in some stands suggests it might be an important natural regulator, which helps to keep M. feytaudi populations at low densities in the areas of Spain studied. This malachiid shows a strong kairomonal attraction to the sexual pheromone of M. feytaudi and its flight activity is significantly correlated with the presence of crawlers of bast scale.

Endosymbiotic organisms are known to manipulate the reproductive biology of their hosts. Incomplete prevalence of endosymbiont inducing thelytokous parthenogenesis results in the coexistence of sexual and asexual individuals, and could account for the maintenance of sexual reproduction in certain populations or species. In the parasitoid Venturia canescens, arrhenotokous ("sexual") and thelytokous ("asexual") individuals occur sympatrically. We aimed to determine whether endosymbionts are implicated in the thelytoky of V. canescens. After screening females of the two reproductive modes for several reproductive parasites: bacteria (Wolbachia, Rickettsia, Bacteroidetes, Spiroplasma, Arsenophonus) and Microsporidia, we concluded that thelytoky in V. canescens is not induced by any of these parasites and confirmed its suitability as a biological model for solving the evolutionary enigma of the maintenance of sexual reproduction.

We conducted a comparative population genetic analysis of levels of genetic variation and its geographical structuring in three closely related species of grasshopper that co-occur in the Mediterranean Basin: Calliptamus italicus, C. barbarus and C. wattenwylianus. In the western part of their distributions 5 populations of C. italicus, 13 of C. barbarus and 10 of C. wattenwylianus were sampled. Bootstrap re-sampling of populations and microsatellite loci within each species indicated a lower level of genetic diversity and higher level of genetic differentiation in C. barbarus, which is less of an outbreak pest species than either of the other Calliptamus species studied. This may be due to lower effective sizes of non-outbreak populations and/or lower gene flow among them.

In the last few decades, Aedes albopictus (Skuse) (Diptera: Culicidae) (= Stegomyia albopicta), the so-called "Asian tiger mosquito", has spread from its native range in southeast Asia to Africa, the Middle East, Europe, the Americas, and Pacific islands. The spread of this species poses a risk to human health as it is considered to be one of the main vectors of dengue and other arboviruses. Aedes albopictus was reported in Croatia in 2004, thereafter it was discovered at several coastal localities in 2005 and to date it has spread to most coastal areas and islands in Croatia. Here we investigate the genetic variability of A. albopictus based on 39 individuals collected during the summer of 2009 along the East-Adriatic coast and islands of Croatia and Montenegro and using two mitochondrial molecular markers: cytochrome oxidase I (COI) and NADH dehydrogenase 5 (ND5). We identified a single ND5 haplotype, corresponding to the previously reported and worldwide-distributed haplotype H3. The COI marker was more variable and we identified four COI haplotypes. In order to identify the geographic origin of the populations that colonized Croatia, we performed phylogenetic analyses of ND5 and COI haplotypes in Croatian populations and other A. albopictus populations retrieved from the GenBank. The phylogenetic tree based on ND5 haplotypes revealed two well supported clades where the unique Croatian ND5 haplotype clustered with the majority of haplotypes originating from South-Asia, America, Europe, and Africa. Another smaller cluster consisted of only Brazilian haplotypes. The phylogenetic tree and haplotype network that resulted from the COI analysis also indicates that the three Croatian COI haplotypes cluster with European and American haplotypes. However the fourth Croatian COI haplotype was the only European haplotype that occurred in a separate clade (group) with Indian, South-Asian, and Brazilian haplotypes. This data suggests there have been several independent introduction events in Croatia.

We investigated the variation in body colour and its thermoregulatory function in Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae), a parasitoid wasp of Spodoptera and other free-living lepidopteran larvae. We show that the body colour of adult wasps darkens when cocoons are kept at low temperatures. The range in the variation in colour, however, differs for different parts of the body and among uniparental (thelytokous) strains. This melanism enables these wasps to attain a body temperature in sunshine up to 2°C. Moreover, this small gain in body temperature can markedly increase the flight activity of wasps at low ambient temperatures. We conclude that the variation in body colour that resulted from rearing the cocoons at different temperatures enable the wasps to adapt to changing thermal environments. The ecological significance of the difference in the degree of melanism of the different strains is discussed.

Larvae of Hermetia illucens feed on different types of decomposing organic matter and their development depends on the quality and quantity of food ingested. In this study the effect of three artificial diets was analyzed, namely hen feed, meat meal and a mixture of these two diets. The effects of diet on ovarian development, size, mortality, duration of the larval and pupal stages and sex ratio were studied. Results indicate that the meat meal diet was the worst of the three diets in terms of percentage mortality and duration of the larval and pupal stages. We conclude that food ingested by the black soldier fly larvae determines both the physiological and morphological development of the adults.

In some species of insects, individuals with fully developed wings and capable of flying coexist with flightless individuals that lack functional wings. Their diets may differ if long-winged individuals are more mobile and therefore likely to be better at finding and utilizing high quality food resources, or if they have different food preferences or physiological requirements. Despite its potential importance, differences in the diet of dispersal phenotypes have not been unequivocally demonstrated under natural conditions. To test for dietary divergence, we compared natural abundances of carbon and nitrogen stable isotope ratios (d¹³C and d¹⁵N) in long- and short-winged free ranging Tetrix subulata pygmy grasshoppers collected as adults from two natural populations. Overall, this comparison of stable isotopes indicated long-term differences in the diet of the two wing morphs in both populations, but not between males and females of the same morph. We conclude that it is likely that the dietary niches of the long winged and flightless individuals differ under natural conditions. This may reduce intra-specific competition, offset the expected trade-off between flight capacity and reproduction and promote ecological speciation.

As urbanisation is set to continue, understanding the impact on wildlife becomes increasingly important if we are to be able to conserve biodiversity. As an excellent group of bioindicators, invertebrates can allow us to understand some of the forces in urban areas which impact upon biodiversity and wildlife populations. This paper discusses some of the trends in the abundance, diversity and richness of invertebrates related to urbanisation and the specific urban environmental and traffic factors which may be at play.

Coloured Moericke water pan traps were used to determine the effect of colour on the preference behaviour of butterflies (Lepidoptera: Hesperioidea, Papilionoidea) over the period 2001 to 2003 in grassland habitats in Eastern Slovakia (Košická kotlina basin). A total of 912 individuals belonging to 53 species and 7 families of butterflies were trapped. The colour of the traps that caught the most butterflies was white, followed by blue, violet, yellow and finally the least were caught by red coloured traps. Ordination analysis showed that some butterfly families and species were more likely to be caught by traps of a specific colour. Measurements of the wavelengths of the colours used revealed that butterflies preferred short-wavelengths light. The effect of colour on the catches did not differ significantly among the sites. The butterflies were more likely to be caught by traps of a certain colour even though the other features of the traps were the same.

In social insects, the high variability in the number of queens per colony raises fundamental questions about the evolution of altruism. It is hypothesized, for instance, that nestmate recognition should be less efficient in polygynous than in monogynous colonies because the presence of several breeders increases the diversity of genetically determined recognition cues, leading to a less specific colonial signature. Recent studies, however, have shown that the link between the number of queens in a colony and the recognition abilities of its members is more complex than previously suggested. Here, we studied intraspecific aggression, diversity of potential recognition cues and genetic structure of colonies in the highly polygynous ant Crematogaster pygmaea. Our results reveal that workers of this species are clearly aggressive towards non-nestmates in field experiments but not in more artificial bioassays conducted in Petri dishes, underscoring the importance of context-dependent aspects of the assessment of nestmate recognition. Behavioural, genetic and chemical data show that C. pygmaea is a multicolonial species, forming spatially restricted and well-defined entities. Therefore, the postulated negative correlation between recognition ability of workers and queen number in a colony is not supported by the results of this study.

Diachasmimorpha longicaudata (Hymenoptera: Braconidae) is a parasitoid wasp widely used in the biological control of fruit flies. In this paper, we present a detailed analysis of the karyotype of this species based on the results of classical and molecular cytogenetic techniques. The cytogenetic analysis confirmed the male and female chromosome numbers previously reported (n = 20, 2n = 40). The entire short arm of most chromosomes is made up of a large constitutive heterochromatic segment. The high heterochromatin content differentiates D. longicaudata from other braconid species. Fluorescence in situ hybridization (FISH) using autologous 18S rDNA probes revealed six clusters of rDNA, i.e. six nucleolar organizer regions (NORs), in the heterochromatic short arms of different chromosomes in the haploid male karyotype. This number is exceptionally high for Hymenoptera, which usually have two NORs in the diploid complement. It is noteworthy that these rDNA-FISH experiments represent the first use of this technique on a braconid species using autologous probes. Since Ag-NOR-bands were coincident with C-positive bands on metaphase chromosomes, it was not possible to identify active nucleoli. The physical characteristics of the D. longicaudata karyotype, especially the content and distribution of heterochromatin and the number and location of rDNA clusters, contribute to a better understanding of the structure and organization of braconid chromosomes and provide a basis for genomic and evolutionary studies.

Many butterfly target species are associated with early successional stages of grasslands. The Blue-spot Hairstreak, Satyrium spini (Denis & Schiffermüller, 1775), is a target species of grasslands. However, it feeds on Common Buckthorn (Rhamnus cathartica), which is associated with late successional stages of grasslands. If S. spini would also be restricted to late seral stages, there might be a management dilemma due to the contrasting requirements of S. spini and other target species. The aim of this study was to determine the oviposition preference of S. spini in calcareous grasslands, and to give management recommendations to promote this species. Therefore, we studied the oviposition microhabitats of S. spini at three representative patches of the Diemel Valley (Central Germany) by comparing environmental conditions on occupied and control host plants. In total we surveyed 1,889 host plants. Altogether we found 148 batches of S.spini on them containing 396 eggs. Most of the eggs were on plants that grew under the warmest conditions. Females preferred to lay eggs on small (< 1.3 m) shrubs of Rh. cathartica fully exposed to the sun growing on steep south- and west-facing slopes. This butterfly showed no difference in its preference for bushes growing in hedges or solitarily. About 80% of the batches of eggs were laid on the upper surface of a twig fork close to the surface of the ground (< 1 m). Our study showed that S. spini is a species characteristic of mid-successional stages of calcareous grasslands. The survival of suitable habitats for S. spini depends on regular management. To achieve this we recommend traditional rough grazing with sheep and goats, which creates open grasslands with small Rhamnus plants. In addition, the shrubs in tall hedges bordering calcareous grasslands should be subjected to cutting on a rotating basis.

The breakdown of the transhumant grazing system in the Spanish Pyrenees has led to a severe decline in the area of pastures. However, in the high mountain zone there are still large areas of species-rich grasslands. The aim of this study was to assess the oviposition preferences of the shrub-feeding Blue-spot hairstreak, Satyrium spini (Denis & Schiffermüller, 1775), in montane common pastures in the Spanish Pyrenees and recommend a way of managing these grasslands that favours this species. Our study showed that females of S.spini laid their eggs on Dwarf buckthorn (Rhamnus pumila Turra) and Alpine buckthorn (R. alpina L.), which are novel host plant records for Spain. A warm microclimate was of crucial importance for egg-laying. Occupied plants grew mostly at sparsely vegetated grassland sites where there were large patches of bare rocks, stones or gravel. Most egg batches were laid close to the ground and 75% consisted of only one egg. The number of batches per R. pumila plant was higher on east-, south- and west-facing slopes than on north-facing slopes. Presence of eggs and the number of egg batches per R. pumila plant were best explained by a long sunshine duration. At high altitudes particularly warm microhabitats seem to be more important for S.spini than at lower altitudes in Central Europe. We assume that the preference for unusually warm microhabitats is explained by the cold climatic conditions near the altitudinal range limit of the species. That most of the eggs were laid singly and not in small batches as in Central Europe might be a risk-spreading strategy to cope with the harsh climatic conditions and the high inter-annual variation in weather conditions in the high mountain zone in the Pyrenees. The best way to maintain open grasslands for S. spini and other thermophilous grassland species in the high mountain zone of the Pyrenees is to use the traditional combination of sheep and cattle grazing.

Aphids play an important role in the life of many ant species supplying them with energy-rich carbohydrate food and in exchange receiving some degree of protection from natural enemies. This study focused on the degree of protection different ants provide myrmecophilous aphids (Hemiptera: Aphididae) in multispecies ant communities. Field investigations were carried out in steppe and forest plant associations in Siberia. The potential level of aggressiveness of six ant species (Formica rufa Linnaeus, F. pratensis Retzius, Lasius fuliginosus (Latreille), L. niger (Linnaeus), Camponotus saxatilis Ruzsky and Myrmica rubra Linnaeus) towards imagines and larvae of ladybirds and lacewings and larvae of hoverflies was tested in the laboratory. A comparative analysis of the occurrence of aphidophages in colonies of the aphid Chaitophorus populeti Panzer and of all aphid-symbionts tended by different ants in the study area has shown that the degree of protection of myrmecophilous aphids from natural enemies significantly differs among ants and is positively correlated with ant colony size. On the whole, the degree of protection of myrmecophilous aphids from aphidophages depends both on the potential level of aggressiveness of ants and their foraging strategy when collecting honeydew (degree of specialisation among honeydew collectors). As the dominant ants Formica s. str. were the most aggressive and provided aphids with the highest degree of protection, we suppose that these ants have the most important influence on the survival of the symbionts in multispecies ant communities whereas the other ants, which live in small colonies of about 10²-10³ workers, appear at least partially to take advantage of the mutualistic relationships of the dominant ants.

Hesperomyces virescens is an ectoparasite of some Coccinellidae, which until the mid-1990s was relatively rarely only reported from warm regions in various parts of the world. Analysis of the host and distribution data of H. virescens recorded in the Western Palaearctic and North America reveals several trends in the occurrence and abundance of H. virescens: (1) it has recently been much more frequently recorded, (2) most of the recent records are for more northerly (colder) localities than the early records and (3) the recent records are mostly of a novel host, the invasive harlequin ladybird (Harmonia axyridis). While in North America H. virescens is almost exclusively found on H. axyridis, all European records of this association are very recent and still less numerous than records of Adalia bipunctata as a host. However, based on a relatively few published cases of the H. axyridis-H. virescens association in Europe and the case described in this paper, it is clear that the harlequin ladybird is currently the main host of this parasite. These changes in the abundance and geographical distribution of H. virescens are probably linked to some features of H. axyridis, such as its abundance, multivoltinism with overlapping generations, high level of promiscuity and overwintering in mass aggregations. The occurrence of these features in one species may make it especially suitable for H. virescens and other parasites that require close contact of host individuals for efficient transmission. Indeed, some of the data indicate that parasites other than H. virescens, like the podapolipid mite Coccipolipus hippodamiae and allantonematid nematodes of the genus Parasitylenchus may also heavily parasitize H. axyridis. We hypothesize that the acquisition of H. axyridis as a host by H. virescens, C. hippodamiae and Parasitylenchus spp. may have further consequences for the abundance and distribution of these parasites, including the expansion of their ranges to other continents colonized by invasive populations of this ladybird and areas in Asia where H. axyridis is native.

This is the first record of the harlequin ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) occurring in the Caucasus (Sochi region of Krasnodar territory, Russia). All the adults collected in the field there and reared from collected eggs, larvae and pupae, and their progeny were H. axyridis f. succinea, which is the most common morph in natural populations in South-Eastern Asia and the Russian Far East as well as in invasive populations in the Americas and Europe. In contrast in Western Siberia f. axyridis predominates and this indicates that an occasional introduction from the closest native range in Siberia cannot be considered as the source of the Caucasian population. It is known that populations of H. axyridis can also differ in their photoperiodic responses. The results of earlier experiments on H. axyridis, which originated from the Russian Far East, indicate that the threshold day lengths for the acceleration of preimaginal development and deceleration of reproductive maturation were 13-14 h, while for the invasive populations of this species in Europe these two thresholds are approximately 12 h. In the population studied, the thresholds for both of these photoperiodic responses were also approximately 12 h. Thus, it is concluded that the population of H. axyridis studied is a further eastward continuation of the invasion of this species in Europe.

Body size is a standard criterion of quality control in insect rearing and often assumed to correlate with fitness in parasitoid wasps, but various metrics of body size can be used. The purpose of this study was to determine which morphological feature provides the best correlation with body size and egg load in a thelytokous population of the parasitoid wasp, Lysiphlebus fabarum (Marshall), when reared on Aphis fabae Scopoli under standardized conditions in a growth chamber (21 ± 1°C, 60-70% RH, and 16L : 8D). Candidate metrics included head width, length and width of the pronotum, length and width of the right forewing, and length of the right hind tibia. In the first experiment, correlations were determined between these measurements and overall wasp body length. As head width and hind tibia length emerged as the most suitable proxies for total body length, the next experiment these two variables as proxies for egg load in females reared from different nymphal instars of the host aphid. There was a non-linear relationship between body size and egg load of wasps emerging from hosts parasitized in different nymphal instars. Egg load increased linearly with body size across all host growth stages, but the second nymphal instar was the most suitable stage for parasitism when speed of development was factored in. The results suggest that head width is a suitable morphometric for monitoring quality control in mass-reared cultures of this wasp.

Cities contain only a low representation of natural and semi-natural habitats, existing in fragments surrounded by built-up areas. In 2003-2004, we surveyed butterflies and Zygaenidae moths in 21 reserves and 4 parks within the city of Prague, Czech Republic, situated from the periphery to city centre. A total of 85 species (47% of the Czech fauna of the study groups) was detected, 22 of them being of conservation concern. Ordination analyses of the local assemblages revealed that the richest sites were large, situated far from the city centre, on alkaline bedrocks, south- to southwest oriented, and hosting high numbers of vegetation types and vascular plant species. We then used generalised linear models to fit responses of individual species to the main ordination gradient, corresponding to increasing urbanisation. Out of 60 species that met criteria for the modelling, none responded positively to urbanisation. Twenty displayed negative linear response; these urban avoiders contained a surplus of mesophilous species presumably preferring rural landscapes. Further 29 species (suburban adaptable) responded in domed manners, peaking at the city periphery. Prevailing among them were xerophilous specialists inhabiting large grassland reserves at the Prague outskirts. Finally, eleven urban tolerant species did not respond to urbanisation at all, containing three highly mobile species, three xerothermophilous specialists, and five species utilising shrubs or trees and finding suitable conditions even in urban parks. Suburban adaptable butterflies apparently benefit from such suburban environments as gardens, road or railway verges, collectively increasing the connectivity of remnants of seminatural habitats. The fact that arboreal species persist even in urban parks, whereas common grassland species are absent there, implies that the quality of urban habitats might be increased by a more sensitive management of urban green spaces, such as leaving aside small temporary fallows or adapting lawns mowing schemes.

Small-scale soil disturbance, such as animal mounds created by subterraneous ecosystem engineers are important microhabitats for species of conservation concern. There are many studies on the effects of ecosystem engineers on plant species diversity and soil properties, but the influence of such organisms on other taxa, such as insects, are rarely analyzed. In this paper, we demonstrate for the first time the role of molehills produced by the European Mole (Talpa europaea) (Linnaeus, 1758) as a larval habitat for a threatened butterfly species within central European calcareous grasslands. We selected the grizzled skipper (Pyrgus malvae) (Linnaeus, 1758) as a study species as previous studies revealed that it prefers warm and open microhabitats for oviposition. Our study clearly showed that host plants occurring on or in the close vicinity of molehills were regularly occupied by immature stages of P. malvae. Occupied host plants at these disturbed sites were characterized by a more open vegetation structure with a higher proportion of bare ground or stones and a lower cover of the herb layer compared with available host plants (control samples). Among molehills those were preferred that had the highest cover of host plants, especially Agrimonia eupatoria. Molehills are important larval habitats for P. malvae in calcareous grasslands on deeper soils. At these sites succession occurs rapidly and the amount of bare ground is usually low, even when they are managed. In contrast to other known breeding sites in calcareous grasslands, molehills with a high cover of host plants provide ideal conditions for the successful larval development of P. malvae: (i) sufficient food during the larval period and (ii) warm microclimatic conditions.

The use of phytoseiid species in biological plant protection is widespread. However, the techniques used to release them differ. The possible release of Amblyseius andersoni (Chant, 1959) using a new method was tested. High numbers of this mite overwinter in the ground litter in Hungarian orchards. By transferring such ground litter to plots in young orchards, the population density was found to be significantly increased in the release compared to control plots; A. andersoni became the dominant phytoseiid species in the new orchard. Due to the rate at which it spreads, this species was also recorded in the control plots towards the end of the growing season (Aug., Sept.), at which time there was no significant difference in the numbers of this species in the treated and control plots. In the winter following release, A. andersoni was found in the ground litter of the orchard.

The Ojców National Park is situated in southern Poland in an area of Jurassic limestone, which determines the hydrochemistry of the water in the River Prądnik. The geochemical index of the sediment in the River Prądnik indicated it is moderately polluted with Pb and Zn, and heavily polluted with Cd compared to unpolluted sediment. The effect of natural and anthropogenic sources on the sediment in the River Prądnik and in appearing of structural and functional alterations in the salivary gland chromosomes of two species of Chironomidae, Micropsectra pallidula and Polypedilum convictum, was investigated. Two types of chromosomal rearrangements (inherited and somatic) were identified in the species studied. Inherited heterozygous inversions occurred at a higher frequency (between 5.55%-57.81%) and may have local adaptive value. In M. pallidula a karyotype divergence consisting of fixed chromosome inversions on arms B and E was recorded. As somatic chromosome rearrangements can be caused by stress agents, we suggest that the somatic aberrations in both of the species studied indicate the existence of pollution, i.e. induced stress. On the basis of these somatic rearrangements the somatic index of both species was defined: M. pallidula - 0.346, P. convictum - 0.555. In addition to these rearrangements functional alterations in key structures, Balbiani rings (BRs) and the nucleolar organizer region (NOR) located on chromosome EF, which significantly decreased their transcriptional activity, were recorded in M. pallidula. Changes in the appearance of the telomere region on chromosome G in P. convictum was considered to be a response to the environmental conditions in the River Prądnik. It was shown that polytene chromosomes are very sensitive to environmental changes and can be used to detect pollutants in aquatic ecosystems.

In this study we evaluate how variations in taxonomic composition and physical structure of macrophyte stands affect plant-dwelling chironomid assemblages in highly variable macrophyte assemblages in two densely vegetated backwaters. By using multivariate explanatory techniques we found that similar vegetation composition did not unequivocally relate to similar chironomid assemblages, moreover the diversity of macrophyte stands did not correlate with the taxonomic diversity of chironomid assemblages in the backwaters investigated. Taxonomic composition and structural characteristics of the vegetation had little influence on the taxonomic or functional (i.e. feeding groups) composition of chironomid assemblages inhabiting them. Similarly, there are only weak relationships between the distribution of certain chironomid species or functional feeding groups and the environmental variables investigated. In general, the structure of the vegetation was more closely associated with the distribution of dominant chironomid taxa than compositional variables (i.e. density of specific macrophyte taxa). In summary, the structure of aquatic vegetation (i.e. position, size of a stand of vegetation, total plant density) and characteristics of the environment where it develops may be more important in shaping plant-dwelling chironomid assemblages than the taxonomic composition of the vegetation.

Because nutrients accrued during larval stages represent the major limiting factor for egg production, the use of adult feeding to enhance the reproductive output in moths is considered to be largely weight-dependent. It is hypothesized, however, that feeding by adults could be adaptive and an effective means of increasing their reproductive success. In order to test this, the calling behaviour of Spodoptera littoralis females that differed in body weight and whether they had fed or not were recorded. Two experiments were carried out. In the first, the calling behaviour of food-deprived females of different body weights was recorded. A strong positive correlation was found between body weight at emergence and the total duration of calling of females on the second to the fifth night after emergence. In the second experiment, groups of female moths that varied in body weight were given access to water or sucrose. Feeding on sucrose significantly reduced the pre-calling period and increased the total time spent calling on the six nights after emergence. The increase in time spent calling associated with ingesting sucrose were proportionately similar for both small and large females, implying that feeding by adults can result in an increase in the time spent calling by moths irrespective of larval nutritional status. Female longevity was also correlated with moth weight at emergence and/or sucrose availability. It is concluded that it is advantageous for female S. littoralis to be large and/or have access to sucrose-rich food in the adult stage as they can spend more time attracting a mate, which increases their chances of mating in early adult life, and their longer adult life may indirectly result in an increase in fecundity.

Most scorpion species are iteroparous, breeding more than once during their life. Some of these species are parthenogenetic. The other reproductive strategy (RS) semelparity, when scorpions breed only a single time during their life, is rare and has been documented only once. The mass allocated by the female to produce either a litter or a single offspring is the reproductive allocation (RA). It is difficult to calculate RA since the difference in female mass before and after parturition is difficult to obtain. In addition, the litter size is hardly ever accurate because of maternal cannibalism. An attempt was made to calculate RA in Nebo hierichonticus (E. Simon, 1872). Based on litter size, on breeding frequency and on longevity of the female, it is possible to estimate the reproductive potential (RP). These aspects of scorpion reproduction are reviewed and the difficulties involved in this study are discussed.

Although the effects of host plant quality on the performance of polyphagous herbivores are largely uniform across insect taxa, there are various exceptions to this rule. In particular, there are scattered reports of cases in which the relative quality of different hosts differs among larval instars of a single insect species. Such cases are explained either in terms of differences in the susceptibility of different aged larvae to plant defences or, alternatively, age-specific nutritional demands. Here we report the results of experiments that show that young larvae of the polyphagous common heath moth Ematurga atomaria (Lepidoptera: Geometridae) consistently attain higher weights on common heather Calluna vulgaris than bilberry Vaccinium myrtillus, whereas the rank order of these host plants is reversed in the final larval instar. Phytochemical analyses showed that differences in nutrient content of these plants are not likely to explain the observed pattern. Instead, the results are more consistent with the idea that the greater chemical defence of bilberry has a relatively stronger influence on young than old larvae.

A global decline in pollinator abundance and diversity has demanded increased research attention to the ecology and genetics of bumblebees. However, as progressively more restrictions are placed on sampling for insects, researchers are increasingly obliged to use archival specimens collected for purposes other than genetic analyses. In this study we assessed the suitability, for population genetic studies, of popular, low-cost methods for preservation and storage of bumblebee specimens. Specimens of Bombus terrestris L. were held under six storage regimes for up to two years. DNA was extracted from the samples using three extraction protocols and the quality of the DNA was examined using PCR amplification of a mitochondrial and a nuclear gene. All extraction and storage methods provided sufficient DNA for successful PCR amplification. However, samples preserved in acetone or at freezing temperatures yielded the highest DNA concentrations. DNA yields from pinned specimens at room temperature declined over time, particularly when using standard extraction techniques. DNA concentrations were significantly lower from specimens preserved in 70% ethanol compared to all other extraction techniques and declined linearly over the two years of storage. These results indicate that two of the most popular insect storage methods (pinning and storage in ethanol) should be avoided for the long-term preservation of genetic material for future studies. We suggest that optimal insect preservation methods should be incorporated into research protocols in order to best capitalise on limited collection opportunities.

Thelytokous parthenogenesis is a type of sex determination in which females are produced from unfertilized eggs. Genetic and endosymbiont-induced forms of thelytoky have been described in the Hymenoptera. Our study has revealed that Wolbachia, Cardinium, Spiroplasma and other endosymbionts are probably absent in Iberian populations of harvester ants, Messor barbarus and Messor capitatus (Hymenoptera: Formicidae: Myrmicinae) and are thus not involved as factors in the sex determination of these two species. Our results lend weight to previous suggestions that bacterial parthenogenesis induction in Hymenoptera is probably limited to the reproductive systems of chalcidoid and cynipoid parasitoid wasps (Hymenoptera: Apocrita: Chalcidoidea and Cynipoidea, respectively).

The ribosomal protein S6 kinase (S6K) plays a pivotal role in developmental processes and cell survival by participating in protein synthesis relevant signaling pathways. In the present study, an S6K gene (AccS6K-p70) was isolated and characterized from the Chinese honeybee, Apis cerana cerana (Fabricius) (Hymenoptera: Apidae), an important economic insect in the agricultural industry. The cDNA of AccS6K-p70 was 1683 bp in length and predicted to encode a protein of 467 amino acid residues. Sequence and structure analysis showed that there was a conserved catalytic domain in AccS6K-p70, whilst a phosphorylation site was found in the conserved part of the catalytic domain. Development relevant transcription factor binding sites found in the 5'-flanking region of AccS6K-p70 suggest that AccS6K-p70 might be involved in A. c. cerana development. Furthermore, quantitative PCR revealed that the expression levels of AccS6K-p70 were higher in head and thorax than in other tissues. The AccS6K-p70 was highly expressed in both larvae and adults compared with that in pupae, whilst expression of the gene was significantly down-regulated by hydrogen peroxide (H₂O₂) (although initially and slightly increased by it) and pyriproxyfen (a juvenile hormone analogue insecticide) stresses. These results suggest that AccS6K-p70 may play critical roles in developmental processes and cell survival in A. c. cerana, whilst both oxidative stress and pyriproxyfen may impair S6K-p70 mediated developmental processes by down-regulation of AccS6K-p70 expression.

A number of aphid species have been shown to produce winged dispersal morphs in the presence of natural enemies. Previous studies tested specialized aphid predators such as ladybirds or lacewing larvae. We confronted colonies of pea aphids with the polyphagous rove beetles, Drusilla canaliculata and Tachyporus hypnorum. For both predators we found that the percentage of winged morphs increased in predator-attacked pea aphid colonies compared to a control. The behaviour of the two rove beetles species was noticeably different. D. canaliculata mostly foraged on the ground and rarely on the plant, while T. hypnorum was almost exclusively observed on the plants, causing a higher number of aphids to drop to the ground, which resulted in a stronger increase in winged morph production. Our results clearly show that not only monophagous aphid predators but also more polyphagous insect predators, which include aphids in their diet, can induce aphids to produce winged morphs.

Ant assemblages were studied in Warsaw in the context of the effects of urban pressure. Four types of urban greenery were selected: (1) green areas bordering streets, (2) in housing estates, and (3) in parks, and (4) patches of urban woodland. In total, there were 27 species of ants. In terms of the total ant activity density, Lasius niger predominated in all the the lawn biotopes (1-3) and Myrmica rubra in the wooded areas. Ant species diversity was highest in parks and wooded areas and lowest in green areas bordering streets. In contrast, activity density was highest in green areas bordering streets and lowest in wooded areas. Some species are found only in a few habitats. Stenamma debile, Lasius brunneus, L. fuliginosus and Temnothorax crassispinus almost exclusively occurred in wooded areas, whereas L. niger was most often found in lawn biotopes. Myrmica rugulosa and Tetramorium caespitum were most abundant in green areas bordering streets, while in parks Lasius flavus, Formica cunicularia and Solenopsis fugax were most abundant. In general, the ant assemblages recorded showed a significantly nested pattern, with biotope type being a significant determinant of nestedness. The assemblages found in green areas in housing estates and bordering streets constituted a subsample of the assemblages in parks and wooded areas. Ant species were non-randomly distributed in this urbanized landscape and the species recorded in the most transformed biotopes constitute subsamples of those inhabiting less transformed biotopes. This finding emphasizes the importance of wooded areas for the maintenance of biodiversity in urban areas.