Insect genital characters are extensively used in species level taxonomy, and their value in species delimitation is great. Based on the lock-and-key hypothesis and that genital differences function as a mechanical isolation system between species, the value of genital characters has been thought to be superior to non-genital characters. Although geographical and other kind of intraspecific variation of genitalia is often assumed very moderate, its real extent is insufficiently investigated. We examined patterns of morphological variation in the male genitalia of the tortricid moth Pammene luedersiana, using geometric morphometric tools including thin-plate spline deformation grids, and found significant variation. This variation is continuous both within and between populations. No systematic shape variation was observed between populations, but genital size showed some geographic variability. The results suggest that genital morphology is not constant and should therefore be used with caution in lepidopteran taxonomy.
Insect cellular immune reaction, which generally includes phagocytosis, encapsulation and nodule formation, is achieved by hemocytes circulating in insect haemolymph. The shift of hemocytes from the normal phase to the adhering phase is an important process in the cellular immune reaction, which includes the attachment of hemocytes to foreign surfaces or other hemocytes via adhesion factors. Neuroglian is one of the adhering factors associated with encapsulation in Manduca sexta and Drosophila melanogaster. Here we studied the localization of neuroglian (MsNrg) in Mythimna separata and its functional role in the cellular immune reaction. The distribution of MsNrg mRNA between hemocyte populations was determined using real-time quantitative reverse transcription PCR and in situ hybridization, which revealed that MsNrg was highly expressed in adhering hemocytes, especially in plasmatocytes. Unexpectedly, the transcript was observed as well in non-adhering hemocytes, implying neuroglian has a function in non-adhering hemocytes. Moreover, we showed that the amount of MsNrg mRNA was not changed by injections of either biotic or abiotic non-selves. Fewer latex beads were fully encapsulated by hemocytes in larvae treated with MsNrg double-stranded RNA than in control larvae, but their ability to achieve phagocytosis and nodule formation remained unchanged by the MsNrg knockdown. These results indicate that the function of neuroglian in the cellular immune reaction is conserved in D. melanogaster and lepidopteran species, and neuroglian in non-adhering hemocytes could possess unidentified function., Kakeru Yokoi, Yoshiaki Kato, Masahiro Suzuki, Ken Miura., and Obsahuje bibliografii
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
Muga silkworm (Antheraea assamensis Helfer) is endemic to Assam and adjoining areas in North-Eastern India, and naturally produces golden silk. From time immemorial, many ethnic and tribal groups have produced muga silk. Muga silkworms are mostly wild unlike the mulberry silkworm, which is completely domesticated. The muga silkworm is a single species with little genetic variation among populations, survives harsh climatic conditions and is subject to various diseases, pests and predators. Due to the high incidence of disease and natural enemies, and variations in climatic conditions, the production of muga silk has recently declined dramatically. In order to improve the productivity of this silkworm it is important to have a better knowledge of both its host plants and biology. Lack of knowledge of its genetics and host plants is a major bottleneck. This paper reviews various aspects of muga silkworm culture, including the availability of different populations, and methods used to select for improvement in survival, cocoon yield, disease resistance, conservation and egg production., Amelendu Tikader, Kunjupillai Vijayan, Beera Saratchandra., and Obsahuje seznam literatury
Larvae and pupae of the obligatorily myrmecophilous Phengaris (Maculinea) arion were found for the first time in nests of Myrmica rugulosa, M. hellenica and M. schencki at a site in eastern Poland. M. sabuleti, commonly considered as a major host of the butterfly and whose abundance is vital for the survival of P. arion populations, was shown to be very rare and not used. Estimated mean density of Myrmica nests was very low, which suggests that relatively vast areas are necessary to support a viable population of P. arion in similar sandy habitats. This may explain the decline and rarity of the butterfly in the whole region, even though its relationships with ants seem not to be very specific there.
The number of larval moults, larval head capsule width and pupal weight were investigated in both direct-developing and diapausing individuals of a South-West European population of Coenonympha pamphilus. The frequency distributions of head widths of successive larval instars overlapped, partly due to variation in the number of larval moults. The larvae that entered diapause went through five instars, instead of the four reported from this species. The evidence indicates that the five instar developmental pathway represents a plastic response rather than an example of compensatory growth. This alternative growth pattern was expressed in response to short photoperiods in parallel with, or as a consequence of, larval diapause. On average, the larvae with five instars had larger heads than their normal siblings. This resulted in comparatively heavier male pupae, while the opposite trend occurred in females. It is concluded that the variation in the number of larval instars is a plastic response to diapause when temperatures remain mild and that it might have an adaptive value in areas with mild winter climates. The sexually dimorphic expression in the larval growth patterns, in terms of pupal weight, may well imply different patterns of allocation of larval resources to adult structures, although sex-dependent differences in investment into purely larval structures cannot be discounted.
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.
The cucumber moth, Diaphania indica (Saunders) (Lepidoptera: Pyralidae), is a major pest of cucurbitaceous plants. The oviposition preference and olfactory response of larvae, mated and unmated male and female adults to volatiles emanating from uninfested and infested plants of four species of cucurbitaceous host plants and odours of conspecifics were recorded. Also the role of experience in the host finding behaviour of D. indica was evaluated. The experiments were done using a wind tunnel, olfactometer attraction assays and oviposition bioassays. The results reveal that fewer eggs were laid on infested plants than on uninfested plants. Females significantly preferred cucumber over squash, melon and watermelon. Cucurbitaceous plants elicited adults of D. indica to fly upwind followed by landing on the plants. The effect of experience on the olfactory preference of D. indica was dependent on the host plant. Females that had experience of cucumber, squash and melon plants were significantly attracted to the same plant, but not in the case of watermelon. Larvae of this pest were attracted only to volatiles of uninfested cucumber, squash and melon, whereas volatiles of conspecifics, infested plants and intact watermelon did not attract larvae. This study is an initial attempt to investigate the role of volatile infochemicals in the host-finding behaviour of D. indica. These results provide baseline information for the development of new control strategies against D. indica.
he painted lady butterfly (Vanessa cardui) (Lepidoptera: Nymphalidae: Nymphalinae) is well known for its seasonal long-distance migrations and for its dramatic population fluctuations between years. Although parasitism has occasionally been noted as an important mortality factor for this butterfly, no comprehensive study has quantified and compared its parasitoid complexes in different geographical areas or seasons. In 2009, a year when this butterfly was extraordinarily abundant in the western Palaearctic, we assessed the spatial and temporal variation in larval parasitism in central Morocco (late winter and autumn) and north-east Spain (spring and late summer). The primary parasitoids in the complexes comprised a few relatively specialized koinobionts that are a regular and important mortality factor in the host populations. However, there was a strong seasonal variation in the level of parasitism. In Spain percentage parasitism was more than four times higher in late summer than in spring (77.3% vs. 18%), while in Morocco it was five times higher by the end of winter than in the autumn (66.2% vs. 13.2%). In both regions the build up of parasitoid populations occurred after V. cardui had bred in the same general area over successive generations, and this may represent a selective force favouring seasonal migration to enemy-free space., Constanti Stefanescu ... [et al.]., and Obsahuje seznam literatury
The extensive genus Erebia is divided into several groups of species according to phylogenetic relatedness. The species Erebia medusa was assigned to the medusa group and E. epipsodea to the alberganus group. A detailed study of the morphology of their copulatory organs indicated that these species are closely related and based on this E. epipsodea was transferred to the medusa group. Phylogenetic analyses of the gene sequences of mitochondrial cytochrome C oxidase subunit I (COI) and mitochondrial NADH dehydrogenase subunit 1 (ND1) confirm that E. medusa and E. epipsodea are closely related. A possible scenario is that the North American species, E. episodea, evolved after exclusion/isolation from E. medusa, whose current centre of distribution is in Europe., Martina Šemeláková, Peter Pristaš, Lubomír Panigaj., and Obsahuje seznam literatury