Host age preference and biology of Coccygidium luteum (Hymenoptera: Braconidae), a larval parasitoid of the fall armyworm.

Abstract

Coccygidium luteum (Hymenoptera: Braconidae), a solitary larval parasitoid, is associated with the fall armyworm (FAW), in Africa. However, there is very limited information on reproductive biology, and other biological parameters that influence its life strategies. We conducted laboratory experiments to gain new insights into the biology of C. luteum reared on FAW as the host. Host age preference, reproductive biology, lifetime fecundity, life cycle, and adult longevity were studied under laboratory conditions of 28 ± 1°C and 70 ± 3% relative humidity. This study revealed that C. luteum prefer early (1st-3rd) instars of FAW for oviposition. The maximum parasitism rate was 80% at second instar larvae. A mean pre-oviposition period of 0.38 ± 0.51 days, oviposition period of 5.13 ± 0.64 days, and no post-oviposition period were observed. The mean lifetime parasitism rate of FAW larvae by female C. luteum was 49 ± 24. Longevity of unmated C. luteum was 14.44 ± 1.43 days for males and 12.83 ± 1.12 days for females. Mated ovipositing females lived for 7 days. Mean female and male progenies per adult female C. luteum was 28.11 ± 8.18 and 39.89 ± 4.76 respectively, with an overall sex ratio of 1.42 at 28 ± 1°C using second instar larvae. Total life cycle from oviposition to adult emergence was 23 ± 1 days. This study provides the basic information about C. luteum that could be utilised for mass rearing of this parasitoid under an augmentative biological control of FAW programme.