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
Climate change may facilitate shifts in the ranges and the spread of insect pests, but a warming climate may also affect herbivorous insects adversely if it disrupts the locally adapted synchrony between the phenology of insects and that of their host plant. The ability of a pest species to colonize new areas depends on its ability to adjust the timing of phenological events in its life cycle, particularly at high latitudes where there is marked seasonality in temperature and day length. Here we incubated eggs of three species of geometrid moth, Epirrita autumnata, Operophtera brumata and Erannis defoliaria from different geographical populations (E. autumnata and O. brumata from Northern Finland, E. autumnata and E. defoliaria from Southern Finland and all three species from Germany) in a climate chamber at a constant temperature to determine the relative importance of geographic origin in the timing of egg hatch measured in terms of cumulative temperature sums (degree days above 5°C, DD5); i.e. the relative importance of local adaptation versus phenotypic plasticity in the timing of egg hatch. In all three species, eggs from northern populations required a significantly lower temperature sum for hatching than eggs from southern populations, but the differences between them in temperature sum requirements varied considerably among species, with the differences being largest for the earliest hatching and northernmost species, E. autumnata, and smallest for the southern, late-hatching E. defoliaria. In addition, the difference in hatch timing between the E. autumnata eggs from Southern Finland and Germany was many times greater than the difference between the two Finnish populations of E. autumnata, despite the fact that the geographical distances between these populations is similar. We discuss how these differences in hatching time may be explained by the differences in hatch-budburst synchrony and its importance for different moth species and populations. We also briefly reflect on the significance of photoperiod, which is not affected by climate change. It is a controller that works parallel or in addition to temperature sum both for egg hatch in moths and bud burst of their host plants., Julia Fält-Nardmann, Tero Klemola, Mechthild Roth, Kai Ruohomäki, Kari Saikkonen., and Obsahuje bibliografii
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
This study reports the results of a molecular phylogenetic analysis of thirty three species of Ennominae (Lepidoptera: Geometridae). The aim of this analysis was to determine the phylogenetic affinities of 13 European species not previously studied using these methods. Fragments of seven nuclear genes, elongation factor 1 alpha (EF-1α), wingless (wgl), isocitrate dehydrogenase (IDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ribosomal protein S5 (RpS5) and expansion segments D1 and D2 of the 28S rRNA gene and fragment of one mitochondrial gene, cytochrome oxidase subunit I (COI), were used. In the analysis using Bayesian phylogenetic inference, original gene sequences of the target species were combined with a larger data matrix of 20 species of Ennominae, used in a previous study (Wahlberg et al., 2010, Mol. Phylogenet. Evol. 55: 929-938). Most notably, the results indicate that the representatives of the genera Cepphis, Plagodis, Pseudopanthera and Selenia form a well-supported monophyletic group which appeared as the sister clade to the rest of the "ennomine" group of tribes. On the other hand, Crocallis and Opisthograptis group together with Ennomos. These results conflict with previous tribal subdivisions of the subfamily pointing to the need to reconsider the concepts of Ennomini and Ourapterygini. Within the tribe Macariini, the genus Macaria appears to be more closely related to Itame (= Speranza) than to Chiasmia clathrata. The emerging phylogenetic tree of Ennominae suggests only a limited phylogenetic inertia in body size making this group a promising target for comparative studies on this central life history trait and its correlates. and Erki Õunap, Juhan Javoiš, Jaan Viidalepp, Toomas Tammaru.
Plant volatiles can synergize the response to moth pheromone. Synthetic pheromone analogs, in turn, have the opposite effect in reducing pheromone attractiveness. To determine how these two types of stimuli interact and influence male moth behaviour, we performed wind tunnel experiments on the grapevine moth, Lobesia botrana. We noticed that a blend of host plant volatiles [(E)-β-caryophyllene, 1-hexanol, (Z)-3-hexenyl acetate and 1-octen-3-ol in a 100:20:10:5 ratio] significantly increased the response of males to an optimized blend of sex pheromone [(7E,9Z)-dodeca-7,9-dienyl acetate (E7,Z9-12:Ac), (7E,9Z)- dodeca-7,9-dienol (E7,Z9-12:OH) and (Z)-9-dodecenyl acetate (Z9-12:Ac)] in a 100:10:2 ratio. However, the response of males to the natural attractant was significantly reduced by two analogs [(9E,11Z)-tetradeca-9,11-dien-2-one (MK 2) and [(9E,11Z)-1,1,1-trifluoro-tetradeca-9,11-dien-2-one (TFMK 3)], of the major component of the sex pheromone of the insect (E7,Z9-12:Ac). When both stimuli were tested on males at pheromone:analog:plant volatile blend 1:100:1000 ratio, the plant blend offset the inhibitory effect induced by TFMK 3 but not that of MK 2. Our results show for the first time that under laboratory conditions plant volatiles can prevent inhibition by a pheromone analog., Albert Sans, Miguel Morán, Magí Riba, Ángel Guerrero, Jaume Roig, César Gemeno., and Obsahuje bibliografii
Several studies address the question of which forest attributes are most important for the conservation of biodiversity. Unfortunately, there are no unequivocal answers because the response of a biological group to changes in forest structure depends on its natural history and scale of organization. It is important to increase our knowledge of the potential relationships between under studied groups of species and forest variables in order to adopt timber harvesting strategies not detrimental to biodiversity, especially in old-growth forests. We assessed the importance of 10 forest attributes and old-growth for Psychidae (Lepidoptera) species and communities. Research was carried out in 12 forest stands in a mountainous beech dominated landscape in southern Italy, in the middle of the Mediterranean Basin. Samples were collected in 2001 and 2013 and data were merged after pairwise comparison analyses that confirmed the long term stability of communities. Correspondence Analysis, Cluster Analysis and non-parametric Spearman Rank Order Correlation were used to identify determinants of Psychidae abundance and diversity. We collected 2,732 Psychidae belonging to 8 species. Correspondence analysis identified old-growth as the main determinant of communities. Most significant attributes for individual species were beech dominance, diameter at breast height and its standard deviation. For Taleporia defoliella there were positive correlations with these forest parameters, whereas for Psyche crassiorella the correlations were negative. This study underlined the importance of forest attributes associated with old-growth forests for sustaining biodiversity. These findings indicate the need to incorporate these attributes in forest planning, especially those aspects that are easily recognizable such as the number of large trees., Stefano Scalercio, Teresa Bonacci, Rosario Turco, Vincenzo Bernardini., and Obsahuje bibliografii
Paysandisia archon (Burmeister, 1980) (Lepidoptera: Castniidae) is an accidentally introduced pest that damages palm trees in the northern Mediterranean area. To our knowledge, there are no experimental studies on its mating behaviour, and little is known about its biology and ecology. In the present study, we used outdoor experiments to investigate several characteristics of the reproductive behaviour of P. archon: sexual maturity, diel periodicity of mating, occurrence of polyandry and delay between mating and laying eggs. The results indicate that 73% of the individuals studied were sexually mature three hours after adult emergence. Mating peaked between 14:00 h and 15:00 h and 87% of the females were fertilized and started laying eggs 1.25 (± 1.14) days after mating. Females were generally monandrous, but nevertheless remained attractive after mating. The results of this study provide the necessary background knowledge for studying several aspects of P. archon reproductive biology, in particular oviposition, sex pheromones and their role in mediating mating behaviour in this pest. These results are the first step in developing tools for monitoring populations of this pest., Roxane Delle-Vedove ... [et al.]., and Obsahuje seznam literatury
The effects of tannic acid on mean values and genetic variation in fitness-related traits (mass, relative growth rate) and specific activities of digestive enzymes (total proteases, a-glucosidase and lipase), and genetic variation in their plasticity, were investigated in fifth instar larvae of Lymantria dispar L. (Lepidoptera: Lymantriidae) originating from two populations with different host use histories (oak and locust-tree). The two populations did not differentiate with respect to fitness-related traits, i.e. adverse effects of tannic acid were similar in both populations. However, Robinia larvae, which originated from the locust-tree forest, were characterized by higher total protease and lipase activity and lower a-glucosidase activity than Quercus larvae, which originated from the oak forest. Higher plasticity of lipase and lower plasticity of a-glucosidase in response to tannic acid were also recorded. Quantitative genetic analysis revealed mostly significant expression of genetic variation in the examined traits and trait plasticity, suggesting the potential for evolution of adaptive plastic responses to new environmental conditions and presence of a stressor. The genetic correlations observed between the environments significantly differed from “one”, which indicates there are no constraints on the evolution of trait plasticity., Marija Mrdakovic ... [et al.]., and Obsahuje seznam literatury
1_The young larvae of insects living on dry food produce large amounts of water by the metabolic combustion of dietary lipids. The metabolic production of water needed for larval growth, previously known as hypermetabolic responses to juvenile hormone (JH), is associated with a 10- to 20-fold increase in the rate of O2 consumption (10,000 µl O2/g/h in contrast to the usual rate of 500 µl O2/g/h). Growing and moulting larvae are naturally hypermetabolic due to the endogenous release of JH from the corpora allata. At the last, larval-pupal or larval-adult moult there is no JH and as a consequence the metabolic rate is much lower and the dietary lipid is not metabolized to produce water but stored in the fat body. At this developmental stage, however, a hypermetabolic response can be induced by the exogenous treatment of the last larval instars with a synthetic JH analogue. In D. vulpinus, the JH-treated hypermetabolic larvae survive for several weeks without moulting or pupating. In T. castaneum and G. mellonella, the JH-treated hypermetabolic larvae moult several times but do not pupate. All these larvae consume dry food and the hypermetabolic response to JH is considered to be a secondary feature of a hormone, which is produced by some subordinated endocrine organ., 2_The organ is most probably the controversial prothoracic gland (PG), which is a typical larval endocrine gland that only functions when JH is present. According to our hypothesis, PG activated by JH (not by a hypothetical PTTH) releases an adipokinetic superhormone, which initiates the conversion of dietary lipid into metabolic water. This type of metabolic combustion of dietary lipid produces large quantities of endothermic energy, which is dissipated by the larvae in the form of heat. Thermovision imaging revealed that the body of hypermetabolic larvae of G. mellonella can be as hot as 43°C or more. In contrast, the temperature of "cold" normal last instar larvae did not differ significantly from that of their environment. It is highly likely that thermovision will facilitate the elucidation of the currently poorly understood hormonal mechanisms that initiate the production of metabolic water essential for the survival of insects that live in absolutely dry conditions., Karel Sláma, Jan Lukáš., and Obsahuje seznam literatury