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
Ornithologists in Finland recorded the autumn migration of the Red Admiral butterfly, Vanessa atalanta (L.). In the best year, 1998, 1240 migrants were counted from a bird tower in September. That is, half a million butterflies migrated over a 100-km front. The butterflies were flying above forests riding on cool northerly winds. Radar indicated that a large proportion migrated at high elevations outside the visible range. These records help to resolve an "evolutionary puzzle" of why migrant butterflies and moths travel to northern latitudes when their offspring have limited possibilities of returning south. Until now, the only butterfly for which a high-elevation return migration on northerly winds is known is the American Monarch Danaus plexippus (L.).
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
Drtivá většina prací, které se zabývají UV-reflektancí u motýlů, je věnována jejímu významu v pohlavním rozmnožování. Existuje jen několik studií, které se zabývají vlivem různých ekologických faktorů na UV-reflektantní kresby. Tento článek je v první řadě souhrnem různých hypotéz o tom, jak může prostředí ovlivňovat variabilitu v tvaroprostoru těchto vzorů či intenzitě UV-reflektance. Text je doplněný o výsledky vlastního výzkumu této problematiky na příkladu žluťáska řešetlákového (Gonepteryx rhamni)., The majority of studies on the subject of UV-reflectance of butterflies is primarily concerned with sexual selection. The article gives a summary of various hypotheses about the matter in which particular environmental factors influence the morphospace of UV-patterns and the intensity of UV-reflectance, together with the results of my own research on the Common Brimstone (Gonepteryx rhamni)., and Pavel Pecháček.