Quantitative community-wide moth surveys frequently employ flight-interception traps equipped with UV-light emitting sources as attractants. It has long been known that moth species differ in their responsiveness to light traps. We studied how the settling behaviour of moths at a light trap may further contribute to sampling bias. We observed the behaviour of 1426 moths at a light tower. Moths were classified as either, settling and remaining still after arrival, or continually moving on the gauze for extended periods of time. Moths that did not move after settling may not end up in the sampling container of the light trap and therefore are under-represented in automated trap samples relative to their true proportions in the community. Our analyses revealed highly significant behavioural differences between moths that differed in body size. Small moths were more likely to remain stationary after settling. As a corollary, representatives of three taxa, which in Europe are predominantly small species (Nolidae, Geometridae: Eupitheciini, Erebidae: Lithosiini), usually settled down immediately, whereas most other moths remained active on or flying around the trap for some time. Moth behaviour was also modulated by ambient temperature. At high temperatures, they were less likely to settle down immediately, but this behavioural difference was most strongly apparent among medium-sized moths. These results indicate the likely extent of the sampling bias when analysing and interpreting automated light-trap samples. Furthermore, to control for temperature modulated sampling bias temperature should always be recorded when sampling moths using flight-interception traps. and Mirko Wölfling, Mira C. Becker, Britta Uhl, Anja Traub, Konrad Fiedler.
a1_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, a2_urban green spaces, such as leaving aside small temporary fallows or adapting lawns mowing schemes., and Martin Konvicka, Tomas Kadlec.
Which factors influence the occurrence, population size and density of species in fragmented habitat patches are key questions in population and conservation ecology. Metapopulation theory predicts that larger and less isolated habitat patches should positively influence species occurrence and population size. However, recent studies have shown that habitat quality, human activity and permeability of the landscape surrounding habitat patches may be also important. In this paper we test the relative effects of habitat patch characteristics, human settlement and landscape permeability on the occurrence, local population size and density of the Chalk-hill Blue Polyommatus coridon a charismatic butterfly inhabiting calcareous grasslands in a fragmented landscape in southern Poland. Patch occupancy rate (corrected for the butterfly detection probability) was 0.45. Habitat patch area, proximity of human settlement and cover of larval food plants positively affected occurrence of the Chalk-hill Blue. Local population size of the Chalk-hill Blue was positively affected by patch area and proximity of human settlement, and negatively by patch isolation. Local density was higher in patches located close to human settlement. Our study is one of the few showing a positive effect of human settlement on a grassland specialist butterfly although the mechanism hidden behind this phenomenon is unknown and requires further examination. In order to maintain local populations of the Chalk-hill Blue in southern Poland, conservation action should be focused on large, closely connected calcareous grasslands. Moreover, extensive management of this habitat should be maintained by local inhabitants who are better placed to undertake such work. and Zuzanna M. ROSIN, Piotr SKÓRKA, Magdalena LENDA, Dawid MORON, Tim H. SPARKS, Piotr TRYJANOWSKI.
Larvae of Dendrolimus punctatus overwinter in diapause. In the Yangtze River Region, this species is multivoltine at altitudes below 400 m and univoltine above 700 m a.s.l. The photoperiodic response of the univoltine population, investigated at five day lengths (11.5, 12.5, 13.5, 14.5 and 15.5 h) at 27 + 1C, indicates that D. punctatus is a long-day species. Diapause was induced in 95-100% of the individuals by three short photophases (11.5-13.5 h), while diapause incidence decreased steeply with increase in day length down to 10% at 15.5 h. The critical daylength (CDL = day length resulting in a 50% incidence of diapause) is 14.6 h. When induced by critical or longer photophases (14.5 and 15.5 h), diapause terminated spontaneously, without any change in photoperiod or temperature. Diapause induced at shorter photophases was more intense and not terminated without activation by diapause averting conditions. Larvae in diapause lived for up to 190 d when kept under a 11.5 h photophase during which they remained sensitive to the photoperiodic signal. In transfer experiments, diapause was terminated after an increase in photoperiod, even if it was within the range of diapause inducing photoperiods: from 11.5 h to 13.5 h. This study revealed that the univoltine hill dwelling population of D. punctatus undergoes a facultative diapause. Although potentially multivoltine they are univoltine because of the low temperatures at that altitude., Ju-Ping Zeng, Yong Wang, Xing-Ping Liu., and Obsahuje seznam literatury
1_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., 2_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., Gregor Stuhldreher, Luis Villar, Thomas Farthmann., and Obsahuje seznam literatury
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., Lenka Kočíková ... [et al.]., and Obsahuje seznam literatury
The carob moth, Ectomyelois ceratoniae (Lepidoptera: Pyralidae), is a serious pest and causes a considerable loss of yield of pomegranate in Iran. Apanteles myeloenta (Hymenoptera: Braconidae) is the dominant parasitoid of this pest parasitizing it more than 30% in recent years. This parasitoid is a candidate for augmentative biological control program to reduce the level of the infestation of fruit overwinter. The objective of this research was to optimize the mass production of A. myeloenta. The mean developmental time of females was 28 days and of males 27 days. Pupal development lasted 7 days. The second instar was the preferred host and most heavily parasitized (45%). Wasps that started their development in second instar hosts produced the highest progeny and those that started in third instar hosts survived as adults for longest. The sex ratio (females to males) of A. myeloenta that emerged from carob moth larvae parasitized in the first instar was 1 : 3.5, in the second instar 1 : 3 and in the third instar 1 : 2. The influence of different host ages on the functional response of A. myeloenta to host density was assessed. Logistic regression indicated a type II functional response to different densities of all the stages of the host tested., Hossein Kishani Farahani, Seyed Hossein Goldansaz., and Obsahuje seznam literatury
Steroid hormone 20-hydroxyecdysone and the sesquiterpenoid juvenile hormone are the main regulators of insect development; however, it is unclear how they interact in the regulation of metamorphic events. Using the silkworm, Bombyx mori, we show that the juvenile hormone analogue fenoxycarb affects the cascade of ecdysone regulated genes that control the programmed cell death in the larval midgut. Morphological changes that occur during cell death were investigated by studying cross-sections of the midgut stained with hematoxylin and eosin. Apoptosis-specific DNA fragmentation was detected using TUNEL assay. Expression patterns of genes ATG8 and ATG12, which were used as indicators of autophagy, and genes of the ecdysone-regulated gene cascade were examined using real-time quantitative polymerase chain reaction. Fenoxycarb application on day 0 of the 5th larval instar extended the feeding period and postponed programmed cell death in mature larval midgut. This effect was probably due to a delay in ecdysone secretion and associated changes in gene expression were mostly not a direct response to the fenoxycarb. However, differences in the gene expression patterns in the control and fenoxycarb treated insects during the prepupal and early pupal stages indicated that fenoxycarb may also exert a more direct effect on some genes of the ecdysone regulated gene cascade., Ebru Goncu, Ramazan Uranli, Osman Parlak., and Obsahuje bibliografii
The theory of life history evolution generally predicts a negative across-environment correlation between development time and size at maturity in response to variations in environmental quality. Deviations from this pattern occur under specific circumstances. In particular, organisms may mature both early and at a small size when (1) some ultimate change (e.g. time constraint, resource exhaustion) in the environment precludes further growth, or (2) when there are predictable among-environment differences in mortality rates. The first scenario is frequently documented in insects but evidence for the second possibility is scarce. Here we report a crowding-induced plastic response resulting in a clear positive across-environment correlation between final weight and development time in a geometrid moth. The response was apparent during the entire larval period and in the last larval instar. Crowding also led to increased growth rates. As outbreaks have not been reported for this species it is unlikely that early pupation is a response to anticipated food shortage. Instead, we suggest that crowded larvae may perceive a higher risk of predation, perhaps because they are unable to distinguish conspecifics from potential predators. A possibility for a plastic increase in growth rate implies that the uncrowded larvae grow at submaximal rates, which indicates a cost of high growth rate., Helen Vellau, Toomas Tammaru., and Obsahuje seznam literatury
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., Merle Streitberger, Thomas Fartmann., and Obsahuje seznam literatury