We present the results of the first study on the karyotypes of four European species of Roncus: Roncus alpinus L. Koch, 1873, Roncus lubricus L. Koch, 1873, Roncus transsilvanicus Beier, 1928 and Roncus sp. The diploid number was 2n = 23 in Roncus sp., 2n = 43 in R. alpinus and R. transsilvanicus and 2n = 45 in R. lubricus. Telocentric autosomes predominate in species with a high chromosome number and metacentric autosomes in Roncus sp. We assume that the ancestral situation for this genus is a high number of chromosomes. A low number of chromosomes is very likely a consequence of centric fusions, which have possibly played a very important role in karyotype evolution in the genus Roncus. All the species analyzed have the X0 sex chromosome system. The X chromosome is metacentric and is the smallest element in the karyotypes of all the species analyzed., František Šťáhlavský, Jana Christophoryova, Hans Henderickx., and Obsahuje seznam literatury
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., Árpád Szabó, Béla Pénzes., and Obsahuje seznam literatury
Invertebrate diversity has rapidly declined throughout Europe during the last century. Various reasons for this decrease have been proposed including human induced factors like climate change. Temperature changes alter distributions and occurrences of butterflies by determining habitat conditions at different scales. We evaluated changes in the composition of butterfly communities recorded at nine areas of fallow ground in south-western Germany in 1973, 1986, 2010 and 2012 using Pollard’s transect technique. To demonstrate the importance of climatic changes in affecting butterfly communities, we calculated the community temperature index (CTI) for each butterfly community in each year. Although they increased slightly, the CTI-values did not match the temperature trends recorded in the study region. However, the reduction in the standard deviations of the CTIs over time is reflected in the marked loss of cold- and warm-adapted species due to their inability to cope with temperature and land-use induced habitat changes. Results of our butterfly surveys indicate a marked decline in species richness and striking changes in the composition of the butterfly communities studied. This trend was most pronounced for habitat specialists, thus mirroring a depletion in trait diversity. Our results indicate that, in the course of large-scale anthropogenic changes, habitat degradation at smaller scales will continuously lead to the replacement of habitat specialists by ubiquitous species., Katharina J. Filz ... [et al.]., and Obsahuje seznam literatury
To understand the factors governing the diversity, abundance and host associations of parasitoids attacking frugivorous drosophilid flies on Iriomote-jima, a subtropical island of Japan, we monitored parasitism on several occasions over the period 2003–2009. Fifteen drosophilid and 12 parasitoid species were recorded. Three species of Drosophila, D. bipectinata, D. albomicans and D. takahashii, bred abundantly in banana baits, though their abundance varied between years and seasons. Frequent parasitoid species were Asobara japonica, A. pleuralis (Braconidae), Leptopilina ryukyuensis and L. pacifica (Figitidae). L. victoriae was recorded only in December 2003. In addition, host acceptance and host suitability of the four most frequently recorded parasitoid species were studied in the laboratory. Most parasitoid and drosophilid species showed species-specific associations with more than one antagonist species, suggesting that they have been subjected to complex coevolutionary interactions. In addition, host range of most of the parasitoid species included one of the three major Drosophila species, suggesting that the abundance of potential hosts is one of the factors determining the evolution of parasitoid host use., Biljan Novkovic ... [et al.]., and Obsahuje seznam literatury
1_The adult demographic parameters, mobility, nectar choice and how the spatial distribution of males and females of Z. polyxena is affected by the distribution and abundance of host-plants, and adults of the opposite sex was studied in a population of this species inhabiting a dense network of permanent habitats (totalling 8.7 ha). The population size was estimated to be ca. 300 individuals. The average adult lifespan was 4.4 days and the maximum 23 (male) and 20 (female) days. The capture probability was higher for males than females due to the more conspicuous behaviour and bounded area of activity of males. A slow increase was followed by a slow decrease in the sex specific parabolic recruitment curve, indicating slight protandry and long emergence period, probably due to habitat heterogeneity. The spatial distribution of host plants (Aristolochia lutea) is the key factor determining the spatial distribution of adults. There was a strong positive correlation between male and female density at each patch, both of which were dependent on the cover of host plants growing in sunny conditions. In searching for A. lutea plants suitable for oviposition, females fly greater distances and move more frequently between patches than males. The size, shape and orientation of the male home range were influenced by the size, shape and orientation of stands of host-plants in sunny positions, but not by patch area. Such adult fidelity to stands of host-plants in sunny positions indicates that the spatial distributions of oviposition sites, mate-locating sites and larval habitats of Z. polyxena overlap. The better statistical fit and much lower probabilities for long-distance movements generated by a negative exponential function than an inverse power function are probably due to the small size and high habitat connectivity of the site studied. Adults were opportunistic in their use of nectar plants., 2_Traditional management is the key factor for maintaining permanent habitats for this species in a grassland biotope., Tatjana Čelik., and Obsahuje seznam literatury
The central-marginal model is widely accepted in chromosomally polymorphic species of Drosophila. In fact, geographically and ecologically central populations of Drosophila show higher levels of polymorphism for paracentric inversions, whereas marginal populations tend to be monomorphic. This fact has been variously explained. Chromosomal polymorphisms in grasshoppers have also been attributed to show such geographical structuring, as in the case of the South-American grasshopper Dichroplus pratensis Bruner (Orthoptera: Acrididae). However, in three other cases involving Acrididae – Leptysma argentina Bruner, Trimerotropis pallidipennis (Burmeister) and Cornops aquaticum (Bruner), it is clear that chromosomal polymorphisms (sometimes with a wide extension over the Argentine area) do not conform to this pattern, and show instead clear correlations with environmental variables, especially minimum temperature, showing low or null frequencies of the rearrangements at one extreme of the environmental gradient and with high or fixed frequencies at the other. Furthermore, this correlation with temperature might also be true in the case of D. pratensis. These aforementioned examples emphasise the dangers of over-generalization when discussing chromosomal polymorphisms, and suggests that such polymorphisms should be considered very much in a case-specific manner in terms of the particular genetic system under study., Pablo C. Colombo., and Obsahuje seznam literatury
The pine bark beetle, Dendroctonus armandi, is a native pest restricted to forests in the Qinling Mountains in China. There was an outbreak of this species there that affected over 0.36 million hectares of pine forest. We hypothesized that there are differences between the numbers of beetles captured by traps baited with various combinations of candidate semiochemicals extracted from the hindguts of D. armandi. In order to determine whether a better operational lure could be developed for D. armandi, we analyzed the volatiles in extracts of the hindgut of D. armandi and tested various combinations of candidate semiochemicals. The GC-MS and GC-FID analyses of volatiles in the extracts of the hindguts of D. armandi collected at different stages of the attack revealed that they are mainly a-pinene, b-caryophyllene and (+)-3-carene with minor amounts of myrcene, limonene, verbenol and verbenone. We tested various combinations of these candidate semiochemicals in order to determine an optimal blend. Our results suggest that the addition of b-caryophyllene to either a-pinene, or blends of a-pinene and other candidate semiochemicals, significantly enhanced the attractiveness of the lures for D. armandi. Field trapping experiments indicated that the blends that included b-caryophyllene, myrcene and other candidate semiochemicals resulted in significantly higher trap catches (161–243% higher) than a-pinene alone. Therefore, a simple lure consisting of a-pinene and b-caryophyllene would be an optimal blend for D. armandi. We conclude that this blend of semiochemicals may provide a better method of reducing the numbers of D. armandi in forest ecosystem., Shou-An Xie, Shu-Jie LV., and Obsahuje seznam literatury
We studied the diet of 10 species of grasshopper belonging to the family Pamphagidae over a period of 3 years at 6 localities in North Eastern Algeria. The species of plants consumed by the grasshoppers was determined by comparing slide mounted specimens of the pieces of plant epidermis in their faeces with those in a reference collection of identified plants collected from the same localities. The percentages of occurrence of the different species of plants in the faeces of the grasshoppers were not related to the abundance of the plants at the sites studied. All the grasshoppers were polyphagous but differed in the percentage of Poaceae in their diets. The diet of Tmethis and Ocneridia contained a higher percentage of Poaceae than the other species and are considered to be ambivores. The three species in the Pamphagus gr. djelfensis complex differ in their diets but all tend to avoid consuming Poaceae and are categorized as forbivores. We also compared the frequency of occurrence of Fabaceae in the faeces and in the field and O. volxemii is the only species that avoided consuming this plant family. The number of sensilla on the labrum was also studied in both sexes of each species. Once one corrects for differences in the size of the labrum, the forbivores have higher numbers of sensilla in groups A1, A2 and A3 (but not A10) than the ambivores. The numbers of sensilla in the A10 group on the labrum of species of Pamphagidae is greater than on that of species of Acrididae, which are mainly graminivores and adapted to semi-arid conditions., Naima Benkenana, Abboud Harrat, Daniel Petit., and Obsahuje seznam literatury
DNA barcoding surveys of small insects usually extract DNA from either a complete insect or a leg. Little is known about how to optimize DNA quantity and quality from different insect parts while preserving a morphological voucher. Here, we quantify DNA yield from different body parts (antenna, hind leg, forewing, hind wing and abdomen) of the micro-moth Cameraria ohridella (Lepidoptera: Gracillariidae) using fluorescent nucleic acid stain (PicoGreen). Samples were preserved in 100% ethanol or dried for three weeks. Our experiment was designed to encompass practical sampling options during fieldwork. DNA quality was assessed by PCR amplification of the mitochondrial COI barcode fragment. In addition, we compared PCR amplification using Platinum® Taq and Qiagen DNA Polymerase and quantified sequence success of amplified DNA. We show that overall, dry parts showed higher eluted DNA yields. PCR and sequencing success rate were slightly higher for dry tissue than ethanol-preserved parts. We also show that Platinum® Taq yielded the highest PCR success rate and that all dry tissues are sequenceable. The optimal strategy for DNA barcoding surveys is therefore to mount micro-Lepidoptera specimens in the field for morphological analysis and sample tissues (hind legs are favoured) from dried samples at a later time (several weeks) in the lab for DNA barcoding using preferentially Platinum® Taq. If larger amounts of DNA are required (i.e. for nuclear gene sequencing), several legs from one side of the specimen or the abdomen should be preserved in pure ethanol., Carlos Lopez-Vaamonde ... [et al.]., and Obsahuje seznam literatury