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
In Lepidoptera, larval dietary experience of volatile cues can induce adult preference for these cues. However, such induction may require several generations, depending in part on the degree of specialization of the insects. In a previous study, using species of noctuid stem borers with different diet breadths, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and monophagous Busseola nairobica, it was shown that in S. nonagrioides, one generation was enough to induce a preference for vanillin in the resulting gravid females, whereas even two generations failed to induce a response in adults of Busseola spp. In this study, we checked whether a higher number of generations of exposure to a vanillin-enriched medium could induce a significant olfactory preference for this medium in the species B. fusca and B. nairobica, which have narrower host-plant utilization ranges than S. nonagrioides. Larvae were reared to the adult stage on an artificial diet enriched with vanillin for periods of from 2 to 7 or 8 generations, followed by two-choice tests on gravid females using a Y-tube olfactometer. The results showed different responses according to the species: for the oligophagous B. fusca, there was no significant effect of the conditioning, while a significant preference for the odours emitted by this new vanillin-enriched diet was recorded for the polyphagous S. nonagrioides and monophagous B. nairobica, but after different numbers of generations. In conclusion, different diet breadths seem to be associated with different levels of plasticity in the odour preference of adults. The implication of this result for insects' adaptability in a changing landscape is discussed., Christophe Petit, Peter Ahuya, Bruno Le Ru, Laure Kaiser-Arnauld, Myriam Harry, Paul-André Calatayud., and Obsahuje bibliografii
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
In this study, we report the development of a set of 15 polymorphic microsatellite markers for the box tree moth, Cydalima perspectalis (Walker), a highly invasive insect in Europe causing significant damage to natural and ornamental Buxus trees. The markers were characterized for four distant populations in both its native (China, two populations) and invasive ranges (Czech Republic and Turkey, one population each). The number of alleles ranged from 2 to 12. No marker significantly deviated from the Hardy-Weinberg equilibrium for all the populations sampled. These microsatellite markers are promising tools for further studies on the invasive pathways and dispersal pattern of the box tree moth in Europe., Audrey Bras, Laure Sauné, Alain Roques, Jérôme Rousselet, Marie-Anne Auger-Rozenberg., and Obsahuje bibliografii
Six microsatellite markers were developed for the larch budmoth Zeiraphera diniana Guénée 1845, using two enrichment protocols. The number of alleles ranged from 3 to 15 per locus and observed heterozygosities ranged from 0.09 to 0.98 for the 69 individuals genotyped. Using these markers significant genetic differentiation between one population from Poland and samples from Alpine populations in France and Switzerland (overall FST = 0.0298) was detected. However, the two Alpine samples did not differ significantly. These microsatellite markers are valuable tools for studying the population genetics of Zeiraphera diniana.
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
Setothosea asigna van Eecke is a dominant defoliator pest in oil palm plantations. To control this pest, a generalist predatory bug, Sycanus annulicornis Dohrn, was used as it is easy to rear on several different species of prey. In this study, we evaluated the influence of different prey on the biology and the ability of S. annulicornis to attack and kill the nettle caterpillar pest S. asigna. Based on laboratory rearing, the larvae of Crocidolomia pavonana F. (Lepidoptera: Crambidae) is a suitable prey for both the growth and development of S. annulicornis, as its nymphal development is shorter (74.0 ± 7.3 days) and adult longevity longer (81.0 ± 9.0 days for male and 64.8 ± 12.4 days for female, respectively) than when reared on the larvae of Tenebrio molitor L. (Coleoptera: Tenebrionidae) (44.0 ± 16.7 days for male and 52.6 ± 14.4 days for female). However, S. annulicornis reared on T. molitor larvae attacked 2.0-2.2 larvae of S. asigna per day, which is more than the 1.6-1.7 larvae per day of those reared on C. pavonana, which indicates that the larvae of T. molitor are a more effective diet for rearing S. annulicornis as biocontrol agent for the S. asigna., Abdul Sahid, Wahyu D. Natawigena, Hersanti, Sudarjat., and Obsahuje bibliografii