Effects of Temperature on Embryonic Development of Banana Weevil Cosmopolites Sordidus germar

Abstract

Developemental threshold and thermal requirements for eggs of banana weevil, Cosmopolites sordidus Germar, were determined under laboratory conditions at constant temperatures of 15,18,25,27,30,32 and 34 °C and a photoperiod of 12:12 L/D. The duration of the egg stage decreased from 34.9 days at 15° C to 4.9 days at 30° C, then increased again to 5.3 days at 32° C. Eggs did not hatch above the latter temperature although signs of embryonic development, such as formation of the head capsule, could be observed. Simple linear regression revealed a developmental threshold of 12° C and a thermal requirement of 89 days-degrees average. Highest rates of eclosion occurred between 25° C and 30° C.

Keywords: Banana weevil, Cosmopolites sordidus, development, thermal requirements