Development and Life Cycle of Anoplophora malasiaca (THOMSON) (Coleoptera: Cerambycidae) on Citrus Trees under Fluctuating and Constant Temperature Regimes

Abstract

White-spotted longicorn beetles, Anoplophora malasiaca (THOMSON), were reared in the laboratory under a varying temperature regime simulating both diel and seasonal fluctuations of natural temperatures, and at three constant temperatures of 20, 25 and 30°C. In the fluctuating-temperature regime, three groups which had different starting points of the seasonal fluctuation were examined to elucidate the effect of different oviposition times on the A. malasiaca life cycle. Small bolts of freshly cut citrus tree were used as food for the larvae. The photoperiod was constant darkness. With fluctuating temperatures, more than 70% of the larvae survived and required 1 or 2 years to complete their life cycle (from egg to adult eclosion). The proportion of individuals with a 2-year life cycle increased as the oviposition time was delayed. Most larvae spent a several-month period without feeding before pupation. Adults emerged simultaneously in June irrespective of their life cycle type. At 20°C, 57% of the individuals completed their development and emerged as adults during the period from 306 to 704 days after oviposition. At 25 and 30°C, all the individuals eventually died during the larval stage. Lower developmental threshold temperatures for eggs and young larvae were estimated to be 6.7 and 11.6°C, respectively.