Galleria mellonella larvae spin protective tubes, which they use until they finish feeding, when they spin cocoons. A feeding choice experiment showed that some of the silk produced by feeding larvae was consumed in addition to the standard diet (STD). To determine the effect of feeding on silk, last instar larvae were fed for 24 h on foods based on STD but modified by replacing the dry milk component (10% of the diet) with equal amounts of different kinds of silk. While each control larva consumed 21 ± 0.5 mg of the STD and produced 4.5 ± 0.1 mg of silk, larvae that ate the food that contained larval silk consumed 10 ± 0.4 mg of food and produced 6.1 ± 0.1 mg silk; the percentage ratio of silk produced to diet consumed was 21% and 61%, respectively. A more pronounced reduction in food consumption occurred when larvae were supplied with Galleria "cocoon" silk or the sericin fraction of such silk, and only 3.8 mg/larva was ingested of the diet containing Bombyx mori cocoon silk or its sericin fraction. Silk production expressed in terms of percentage of diet consumed was always higher than that recorded for larvae fed STD. We conclude that G. mellonella larvae recycle part of the silk that they produce during feeding. Presence of silk in the diet reduces food intake but increases the ratio of silk production to diet consumption. Sericin fraction of the cocoon silk seems to deter feeding., Haq Abdul Shaik, Archana Mishra, František Sehnal., and Obsahuje bibliografii
Performance of the invasive horse-chestnut leaf miner, Cameraria ohridella Deschka & Dimic, 1986 (Lepidoptera: Gracillariidae), was studied on two host plants: the white-flowering horse-chestnut Aesculus hippocastanum L. and the Ohio buckeye Aesculus glabra Willd. C. ohridella developed successfully on both host plants; however, mine density and survival were much higher on A. hippocastanum than on A. glabra. The pupal mass and potential fecundity were strongly affected by the host plant on which the larvae fed. On A. hippocastanum pupae were significantly heavier and females more fecund than those on A. glabra. Furthermore, on both host plants there was a significant positive correlation between the number of oocytes in ovaries and pupal body mass, and as a consequence, heavier females produced more eggs. Our study demonstrates that the mine density, survival, pupal mass and potential fecundity were significantly lower on A. glabra than on A. hippocastanum. The observed lower performance of C. ohridella on the exotic host plant was assumed to be due to its poor food quality (nutritional and chemical composition)., Urszula Walczak, Edward Baraniak, Piotr Zduniak., and Obsahuje bibliografii
To explore the debated phylogenetic relationship of two Hesperiidae subfamilies, Pyrginae and Eudaminae, and contribute to the understanding of the evolution of mitogenomic architecture in butterflies, we sequenced the complete mitogenome of Tagiades vajuna. The mitogenome is a typical circular duplex molecule of 15,359 bp. Apart from the standard 22 tRNAs, it has a tandem duplication of trnS(AGN) and trnE, which is unique in lepidopteran insects. Comparison with Ctenoptilum vasava indicates that the trnS1 duplication is not an ancestral state shared with other species of Tagiadini. Independent origin of the trnS1 duplications was further confirmed by the reconstruction of the ancestral character state based on the topology of the phylogram. Furthermore, comparative analysis of mitogenomes with and without tRNA duplications indicates that tRNA duplication does not alter the codon usage pattern. The mitogenome has negative AT- and GC-skews, and it is highly A+T-biased (79.7%). The AT-rich (or control) region (283 bp) contains "ATAGA" and "ATTTA" motifs. Regarding the phylogenetic analysis, we found that removal of the third codon position (3CP) from datasets used for the mitochondrial phylogenomics of Hesperiidae is likely to produce results that are more consistent: Pyrginae were rendered paraphyletic by Eudaminae in both analyses of the dataset from which the 3CP was removed (13 PCGs + all RNAs), but inclusion of the 3CP resulted in a destabilized topology, resulting in both monophyly and polyphyly. We conclude that even shallow-phylogenies of insects should pay close attention to compositional and mutational biases in mitogenomes., Fang-Fang Liu, Yi-Ping Li, Ivan Jakovlić, Xiang-Qun Yuan., and Obsahuje bibliografii
The tendency for self-superparasitism and it's effects on the quality of the parasitoid Ooencyrtus pityocampae (Mercet) (Hymenoptera: Encyrtidae) in parasitizing a new laboratory host, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae), were investigated. In this study, female parasitoids of various ages (1-, 3- and 5-day-old) were tested individually. Parasitoids were provided with 1-day-old P. ricini eggs at ratios of 5, 10, 20, 30 and 40 host eggs per wasp. The tendency to superparasitize was dependent on the female's age and host density. Five-day-old females showed a strong tendency to superparasitize at low host densities. The development time of wasps in superparasitized eggs was longer than that of wasps in singly parasitized eggs. The size and longevity of adult parasitoids decreased significantly with superparasitism. This work contributes to the development of an efficient mass rearing and laboratory rearing of the parasitoid O. pityocampae using a new host., Hilal Tunca, Maurane Buradino, Etty-Ambre Colombel, Elisabeth Tabone., and Obsahuje bibliografii
When insect herbivores develop over many generations on the same plant species, their descendants may evolve physiological adaptations that enable them to develop more successfully on that plant species than naïve conspecifics. Here, we compared development of wild and lab-reared caterpillars of the cabbage moth, Mamestra brassicae, on a cultivar of cabbage Brassica oleracea (cv. Cyrus) and on a wild plant species, sorrel, Rumex acetosa, on which the wild strain had been collected and reared for two earlier consecutive generations. The lab strain had been reared on the same cabbage cultivar for more than 20 years representing > 200 generations. Survival to adult did not vary with strain or plant species. Both strains, however, developed significantly faster when reared on R. acetosa than B. oleracea. Pupae from the field strain were larger when reared on B. oleracea than on R. acetosa, whereas the identity of the plant species did not matter for the lab strain. Our results show that long-term rearing history on cabbage had little or no effect on M. brassicae performance, suggesting that some generalist herbivores can readily exploit novel plants that may be chemically very different from those on which they have long been intimately associated., Jeffrey A. Harvey, Eke Hengeveld, Miriama Malcicka., and Obsahuje bibliografii
The Mediterranean flour moth, Ephestia kuehniella is a widespread pest of stored products and a classical object in experimental biology. In the present study, we determined its complete mitochondrial genome sequence. The genome is circular, consists of 15,327 bp and comprises 13 protein-coding, 2 rRNA- and 22 tRNA-coding genes in an order typical for the Ditrysia clade of the order Lepidoptera. A phylogenetic study of the Lepidoptera based on complete mitochondrial genomes places E. kuehniella correctly in the family Pyralidae and supports major lepidopteran taxa as phylogenetic clades. The W chromosome of E. kuehniella is an exceptionally rich reservoir of originally mitochondrial sequences (numts). Around 0.7% of the W DNA was found to be of mitochondrial origin, 83% of the mitogenome sequence was represented between 1-11 × in the W chromosome. Phylogenetic analysis further revealed that these numts are an evolutionary recent acquisition of the W chromosome., Katrin Lämmermann, Heiko Vogel, Walther Traut., and Obsahuje bibliografii
At the southern limit of its range the endangered butterfly Coenonympha oedippus inhabits grasslands (wet, dry) that differ significantly in the abundance of its larval hostplants (wet > dry) and mean annual air temperature (wet < dry). We determined the difference in the wing morphology of individuals in the two contrasting habitats to test whether and how traits associated with wing size, shape and eye like spots vary in the sexes and two ecotypes. We show that sexual dimorphism follows the same (wing size and shape, number of eyespots on forewing) or different (relative area of eyespots on hindwings) patterns in the two contrasting habitats. Irrespective of ecotype, females had larger, longer and narrower wings, and more forewing eyespots than males. Sexual dimorphism in the relative area of eyespots on hindwing was female-biased in the wet, but male-biased in the dry ecotype. Ecotype dimorphism in wing size and the relative area of eyespots on the hindwing is best explained by mean annual air temperature and abundance of host-plants. While ecotype dimorphism in wing size did not differ between sexes, neither in direction (wet > dry) or in degree, in the two sexes the relative area of eyespots on hindwing had opposite patterns (males: dry > wet; females: wet > dry) and was more pronounced in males than in females. The differences in wing shape between ecotypes were detected only in the hindwings of males, with more rounded apex in the dry than in the wet ecotype. We discuss the life-history traits, behavioural strategies and selection mechanisms, which largely account for the sex- and ecotype-specific variation in wing morphology., Jure Jugovic, Sara Zupan, Elena Bužan, Tatjana Čelik., and Obsahuje bibliografii
Thermal requirements for flight in butterflies is determined by a combination of external factors, behaviour and physical constraints. Thorax temperature of 152 butterflies was monitored with an infra-red thermometer in controlled laboratory conditions. The temperature at take-off varied from 13.4°C, for a female Heteronympha merope to 46.3°C, for a female Junonia villida. Heteronympha merope, an understorey species, had the lowest recorded take-off temperatures, with females flying at a much lower thorax temperatures than males. Among the tested butterfly species, warming-up rate was positively correlated with take-off temperature and negatively with body mass. Wing loading is a major variable in determining the thorax flight temperature. Butterflies with the highest wing-loadings experienced the highest thorax temperatures at take-off. A notable exception to this rule is Trapezites symmomus, the only Hesperiidae of our data set, which had thorax flight temperatures of 31.5°C and 34.5°C, well within the range of the observed butterflies, despite a wing load ca. five times higher. The high thorax temperature recorded in J. villida is probably linked to its high flight speed. The results highlight the importance of physical constraints such as body size on the thermal requirements for flight across a range of butterfly species., Gabriel Nève, Casey Hall., and Obsahuje bibliografii
Population fluctuations of the well-known oak defoliator, the oak processionary moth (Thaumetopoea processionea L.), were studied using light trap data and basic meteorological parameters (monthly average temperatures, and precipitation) at three locations in Western Hungary over a period of 15 years (1988-2012). The fluctuations in the numbers caught by the three traps were strongly synchronized. One possible explanation for this synchrony may be similar weather at the three trapping locations. Cyclic Reverse Moving Interval Techniques (CReMIT) were used to define the period of time in a year that most strongly influences the catches. For this period, we defined a species specific aridity index for Thaumetopoea processionea (THAU-index). This index explains 54.8-68.9% of the variation in the yearly catches, which indicates that aridity, particularly in the May-July period was the major determinant of population fluctuations. Our results predict an increasing future risk of Oak Processionary Moth (OPM) outbreaks and further spread if the frequency of severe spring/summer droughts increases with global warming., György Csóka, Anikó Hirka, Levente Szöcs, Norbert Móricz, Ervin Rasztovits, Zoltán Pödör., and Obsahuje bibliografii