Climate change and the effect of increasing spring temperatures on emergence dates of the butterfly Apatura iris (Lepidoptera: Nymphalidae)

摘要: Data on pupation and emergence dates for the nymphalid Purple Emperor butterfly Apatura iris have been collected at Basel, Switzerland, between 1982 2002. The has shown to emerge average 9 (males) 12 (females) days ear- lier per decade, 19 24 earlier respectively over study period. Emergence relate strongly spring temperatures, particularly with daily maximum temperatures months March May. Temperatures these increased signifi- cantly during this period (0.7°C 1.8°C decade). Three factors suggest that strongest influence of rise in tempera- tures late larval instar growth development: (i) May dominate date models larvae are feeding faster longer periods month, (ii) Salix caprea flowering date, a surrogate bud burst, is excluded stepwise regression years suggesting tree phenology may be less important than temperature effects later development, (iii) convergence female male time points limits protandrous males. A negative consequence observed lethal extra broods.