Three species ofnymphalid butterflies, Vanessa cardui, V. indica and Nymphalis xanthomelasjaponica, do not exhibit seasonal polyphenism in wing coloration. To deter-mine whether seasonal non-polyphenic butterflies pos...Three species ofnymphalid butterflies, Vanessa cardui, V. indica and Nymphalis xanthomelasjaponica, do not exhibit seasonal polyphenism in wing coloration. To deter-mine whether seasonal non-polyphenic butterflies possess a cerebral factor affecting wing coloration, we used a Polygonia c-aureurn female short-day pupal assay for detection of summer-morph-producing hormone （SMPH） activity in P. c-aureum. When 2% NaCl extracts of 25 brain-equivalents prepared from the pupal brains of V. cardui, V. indica or N. xanthomelasjaponica were injected into Polygonia female short-day pupae, all recipients developed into summer-morph adults with dark-yellow wings, and the average grade score （AGS） of summer morphs showing SMPH activity was 3.8, 3.7 and 4.0, respectively. In contrast, when acetone or 80% ethanol extracts prepared from pupal brains were injected into Polygonia pupae, all recipients developed into autumn-morph adults with a dark-brown coloration and each exhibited an AGS of less than 0.5. Our results indicate that a cerebral factor showing SMPH activity is present in the pupal brain of seasonal non-polyphenic nymphalid butterflies, suggesting that a SMPH and cerebral factor showing SMPH activity occur widely among butterfly species. This finding will improve our understanding of the presence of cerebral factors showing interspecific actions of SHPH.展开更多
The ability to fly is crucial for migratory insects.Consequently,the accumulation of damage on the wings over time can affect survival,especially for species that travel long distances.We examined the frequency of irr...The ability to fly is crucial for migratory insects.Consequently,the accumulation of damage on the wings over time can affect survival,especially for species that travel long distances.We examined the frequency of irreversible wing damage in the migratory butterfly Vanessa cardui to explore the effect of wing structure on wing damage frequency,as well as the mechanisms that might mitigate wing damage.An exceptionally high migration rate driven by high precipitation levels in their larval habitats in the winter of 2018–2019 provided us with an excellent opportunity to collect data on the frequency of naturally occurring wing damage associated with long-distance flights.Digital images of 135 individuals of V.cardui were collected and analyzed in Germany.The results show that the hindwings experienced a greater frequency of damage than the forewings.Moreover,forewings experienced more severe damage on the lateral margin,whereas hindwings experienced more damage on the trailing margin.The frequency of wing margin damage was higher in the painted lady butterfly than in the migrating monarch butterfly and in the butterfly Pontia occidentalis following artificially induced wing collisions.The results of this study could be used in future comparative studies of patterns of wing damage in butterflies and other insects.Additional studies are needed to clarify whether the strategies for coping with wing damage differ between migratory and nonmigratory species.展开更多
文摘Three species ofnymphalid butterflies, Vanessa cardui, V. indica and Nymphalis xanthomelasjaponica, do not exhibit seasonal polyphenism in wing coloration. To deter-mine whether seasonal non-polyphenic butterflies possess a cerebral factor affecting wing coloration, we used a Polygonia c-aureurn female short-day pupal assay for detection of summer-morph-producing hormone （SMPH） activity in P. c-aureum. When 2% NaCl extracts of 25 brain-equivalents prepared from the pupal brains of V. cardui, V. indica or N. xanthomelasjaponica were injected into Polygonia female short-day pupae, all recipients developed into summer-morph adults with dark-yellow wings, and the average grade score （AGS） of summer morphs showing SMPH activity was 3.8, 3.7 and 4.0, respectively. In contrast, when acetone or 80% ethanol extracts prepared from pupal brains were injected into Polygonia pupae, all recipients developed into autumn-morph adults with a dark-brown coloration and each exhibited an AGS of less than 0.5. Our results indicate that a cerebral factor showing SMPH activity is present in the pupal brain of seasonal non-polyphenic nymphalid butterflies, suggesting that a SMPH and cerebral factor showing SMPH activity occur widely among butterfly species. This finding will improve our understanding of the presence of cerebral factors showing interspecific actions of SHPH.
文摘The ability to fly is crucial for migratory insects.Consequently,the accumulation of damage on the wings over time can affect survival,especially for species that travel long distances.We examined the frequency of irreversible wing damage in the migratory butterfly Vanessa cardui to explore the effect of wing structure on wing damage frequency,as well as the mechanisms that might mitigate wing damage.An exceptionally high migration rate driven by high precipitation levels in their larval habitats in the winter of 2018–2019 provided us with an excellent opportunity to collect data on the frequency of naturally occurring wing damage associated with long-distance flights.Digital images of 135 individuals of V.cardui were collected and analyzed in Germany.The results show that the hindwings experienced a greater frequency of damage than the forewings.Moreover,forewings experienced more severe damage on the lateral margin,whereas hindwings experienced more damage on the trailing margin.The frequency of wing margin damage was higher in the painted lady butterfly than in the migrating monarch butterfly and in the butterfly Pontia occidentalis following artificially induced wing collisions.The results of this study could be used in future comparative studies of patterns of wing damage in butterflies and other insects.Additional studies are needed to clarify whether the strategies for coping with wing damage differ between migratory and nonmigratory species.
