Reproductive behavior of Biosteres arisanus (Sonan) (Hymenoptera:Braconidae), an egg-larval parasitoid of the oriental fruit fly

Abstract

The egg-larval parasitoid Biosteres arisanus (Sonan) is a candidate for classical and augmentative biological control programs directed against seven tephritid pest species in many tropical and subtropical areas of the world. Aspects of its reproductive behavior were examined in the laboratory to facilitate its mass production. Mean longevity (±SEM) of host-deprived and ovipositing females was 15.3 ± 0.2 and 18.6 ± 0.2 days, respectively, when reared in groups of 200 ♀♀. However, when reared individually, ovipositing females lived for 21.4 ± 2.1 days. Ovarian maturation peaked at an average of 121.1 ± 5.5 mature eggs per female on the sixth posteclosion day and declined thereafter as the females aged. Mean number of eggs deposited per day was 16.5 ± 1.3 and mean fecundity was 88.4 ± 11.3 eggs per female. Mean potential fecundity (eggs deposited and eggs remaining in ovaries at death) was 133.4 ± 12.8 eggs. When host clutch size increased, B. arisanus female increased its oviposition activity per day. However, percentage parasitism of host eggs remained <50% and, as a result, superparasitism was minimized to <1%. No oviposition preference was detected when Bactrocera dorsalis (Hendel) and Ceratitis capitata (Wiedemann) eggs were presented to B. arisanus females. Size of cage provided for mating and light intensity each had a significant influence on the number of inseminated B. arisanus females. With an exposure period of 6 diurnal h, mean percentage of inseminated females was 77.4 ± 4.3 and 3.0 ± 3.0% when mating occurred in 8.3 and 0.02-m3 outdoor screened cages, respectively. Progeny of B. arisanus was exclusively males when females mated indoors. Increasing the number of inseminated females in the rearing cages significantly increased female oviposition activity.