Geographic variation in the incidence of pupal diapause in Asian and Oceanian species of the flesh fly Boettcherisca (Diptera: Sarcophagidae)

ABSTRACT. The incidence of pupal diapause was examined in nine species of the genus Boettcherisca Rohdendorf ( B.peregrina, B.javanica, B.nathani, B.septentrionalis, B. karnyi, B. koimani, B. timorensis, B. formosensis and B.invaria ) collected from various localities in East Asia and Oceanian islands.
Colonies of B.septenrionalis, B. nathani and B.peregrina obtained from temperate regions of Asia and those of B. formosensis and B.peregrina from the continental subtropics entered pupal diapause in response to photoperiod at 20C.
The incidence of pupal diapause showed a geographic gradient in B.peregrina. No photoperiodically induced diapause was observed in the other five species which are indigenous to the tropical or subtropical habitats.
Different species of Boettcherisca seem to have evolved their pupal diapause independently of one another as an ecophysiological mechanism which enabled those species to expand from the tropical to temperate region.