Effect of temperature on development of Theocolax elegans (Westwood) (Hymenoptera: Pteromalidae) parasitizing larvae of the maize weevil Sitophilus zeamais (Coleoptera: Curculionidae) in brown rice

The development and adult longevity of Theocolax elegans (Westwood) were investigated at six temperatures (20, 25, 28, 30, 32 and 35degreesC), 70-80% RH and a 16L-8D photoperiod. Fecundity was also investigated at 25degreesC and 30degreesC. The hosts were larvae of Sitophilus zeamais Motschulsky reared on brown rice. As the temperature was increased from 20degreesC to 32degreesC, the developmental period decreased from 54.4 to 16.2 days for females and from 53.8 to 15.6 days for males. The developmental period at 35degreesC was longer than at 32degreesC. Males developed faster than females. Adult longevity decreased with increasing temperature from 14.5 to 4.5 days for females and from 20.6 to 3.6 days for males. The mean number of progeny produced per female over a lifetime was 161.0 at 25degreesC and 110.1 at 30degreesC. The intrinsic rate of natural increase (r(m)) was 0.131 females per female per day at 25degreesC and 0.169 females per female per day at 30degreesC.