BOLL-WEEVIL (COLEOPTERA, CURCULIONIDAE) REPRODUCTIVE DEVELOPMENT AS AFUNCTION OF TEMPERATURE

The effect of temperature on reproductive development in the boil weev il, Anthonomus grandis Boheman, was examined at 12.8, 18.3, 23.9, 29.4 , 32.2, and 35.0 degrees C and a 13:11 (L:D) h photoperiod through the use of dissections at specific ages. Logistic functions were used to describe age-frequencies of the presence of eggs, eggs with visible yo lk, mature eggs, early reproductive testes (beginning of visible sperm accumulation in the centers of testis lobes), late reproductive teste s (visible sperm accumulation in outer areas of testicular follicles), and filled seminal vesicles. Development times for 50 and 90% of the populations to attain these development stages were estimated from log istic functions. Biophysical developmental rate models were fitted to the corresponding development rates. Results indicated a marked temper ature dependence of reproductive development with both low- and high-t emperature inhibition at observed temperature extremes. Exposure to lo wer temperatures did not induce morphological characteristics of diapa use. These results suggest a need to reexamine previous studies of dia pause induction in which differences in physiological ages of weevils among induction regimes were not considered.