›› 2004, Vol. 47 ›› Issue (3): 354-359.

• RESEARCH PAPERS • Previous Articles     Next Articles

The role of high temperature in diapause inhibition in larvae of Pseudopidorus fasciata (Lepidoptera: Zygaenidae)

HUA Ai, XUE Fang-Sen*, LI Feng, ZHU Xing-Fen   

  • Online:2004-06-20 Published:2004-06-20
  • Contact: XUE Fang-Sen

Abstract: The role of a high temperature of 31℃ in diapause inhibition in Pseud opidorus fasciata was investigated. All larvae developed without diapause regardless of photoperiod when they were exposed to a high temperature of 31℃. Under a diapause-inducing photoperiod of L12∶D12, nearly all individuals entered diapause when high temperature in the photophase was combined with relatively low temperatures (15-28℃) in the scotophase. However, the incidence of diapause significantly declined when the high temperature in the photophase combined with a much low temperature of 5℃ in the scotophase. Nearly all individuals developed without diapause when the high temperature in the scotophase was combined with relatively low temperatures in the photophase, indicating that the high temperature plays an important role in the period of darkness. The effect of durations (2, 4, 6, 8, 10, 12 h)of high temperature on the incidence of diapause showed that a 2 h high temperature exposure was sufficient to inhibit the incidence of diapause. When a 4 h high temperature exposure was used to interrupt the scotophase at different stages, the results showed that the first 4 h in the darkness was the most sensitive part to high temperature exposure and completely inhibited the incidence of diapause. Finally, the adaptive significance of the mechanism of high temperature regulation in life history of P. fasciata was discussed.

Key words: Pseudopidorus fasciata, high temperature, diapause, photoperiod