Development, Longevity, and Fecundity of Chelonus sp. nr. curvimaculatus (Hymenoptera: Braconidae), an Egg-Larval Parasitoid of Pink Bollworm (Lepidoptera: Gelechiidae)

Detailed biological information is lacking on Chelonus sp. nr. curvimaculatus, an egg-larval parasitoid of Pectinophora gossypiella (Saunders). We conducted laboratory studies to gain new understanding of the biology of C. sp. nr. curvimaculatus reared on this economically important host. Developmental time, adult longevity, and fecundity of C. sp. nr. curvimaculatus were studied under 5 constant temperatures and 3 photoperiods. At 20°C, parasitoid development, from egg to adult, was longer for females (53.6 d) than for males (49.5 d), but at 35°C both sexes developed in a similar period (19.9 d for females and 18.8 d for males). The thermal constant for female and male C. sp. nr. curvimaculatus, from egg to adult, was 366 and 353 above a base temperature of 12,95°C and 12.47°C, respectively. Adult male (≈16.5 d) and female (≈20 d) parasitoids lived longest at 20°C, and at 35°C both lived ≈6.5 d. True and realized fecundity was highest at 25°C (≈1,034 and 420 eggs per female, respectively) and lowest at 35°C (≈119 and 67, respectively). The percentage of superparasitized host eggs was greatest at 25 and 30°C (≈55%), and lowest at 35°C (≈29%). Net reproductive rates (Ro) were variable across all conditions. Based on the realized fecundity, Ro was highest at 20°C (103.37) and lowest at 35°C (32.79). Temperature and the age of the parasitoid had the greatest influence on fecundity. Photoperiod played a minor role in influencing developmental rates, but not adult longevity or fecundity of C. sp. nr. curvimaculatus. This life history and rearing information should be useful in field release studies and the development of future biological control programs for pink bollworm.