TEMPERATURE RESPONSE OF 2 STRAINS OF CERANISUS-MENES (HYMENOPTERA, EULOPHIDAE) REARED ON THRIPS-PALMI (THYSANOPTERA, THRIPIDAE)

The development response to temperature of a Japanese uniparental stra in End a Thai biparental strain of Ceranisus menes (Walker) (Hymenopte ra: Eulophidae) was studied. The parasitoids were reared on first inst ar Thrips palmi larvae in incubators at constant temperatures of 21, 2 3, 25, 27 and 29 degrees C. Total developmental time decreased with th e increase of temperature from 35.1 to 21.9 days in females and from 3 3.4 to 18.8 days in males. Lowest mortality (12%) was recorded in both strains at 23 degrees C and highest (95%) in the Japanese strain at 2 9 degrees C. Seventy-three percent of the Thai parasitoids survived at 29 degrees C, but 39% mortality was observed at 21 degrees C. Percent parasitism ranged from 23.8 to 28.9% at 25-29 degrees C, but decrease d to 11.5% at 21 degrees C. The sex ratio (male:female) was not affect ed by temperature and averaged 1:1.9. A thermal constant of 500 degree -days and a developmental threshold of 8 degrees C (from egg to adult emergence) were obtained for both Japanese and Thai females. For the T hai males, the thermal constant was 333.3 degree-days and the minimum threshold was 13.7 degrees C.