The pod-sucking bug, Clavigralla tomentosicollis, is a key pest of cowpea, an important food legume in West Africa. Gryon fulviventre, an egg parasitoid of this pest is a potential biological control agent and proved that inoculative or inundative releases incowpea fields boost its natural parasitism rates. The current study aimed to determine some biological parameters of G. fulviventre on C. tomentosicollis eggs under laboratory conditions, and the effects of host age and host density on the parasitic abilities of the parasitoid. On average, G. fulviventre development time from egg to adult emergence was 13.14 ± 0.41 days. Female fecundity averaged 27.5 ± 11.21 eggs over their lifetime, with most eggs laid during the first two days of life. The average sex ratio was 73.82% female. The 24-h-old eggs of C.tomentosicollis are preferred by G. fulviventre females for oviposition. The intrinsic rate of population increase (rm) was 0.206 ± 0.01 and the population doubling time was 3.37 ± 0.19 days. The functional response of G. fulviventre females was dependent on host density. Thus, G. fulviventre exhibits some characteristics that may make it a good biological control agent. The results will contribute to the mass production of this beneficial agent, an essential step before implementing the parasitoid release strategies (PDF) Studies on life history traits of the oophagous parasitoid, Gryon fulviventre Crawford (Hymenoptera: Scelionidae), a potential biocontrol agent of the cowpea pod-sucking bug, Clavigralla tomentosicollis Stäl. (Hemiptera: Coreidae) in Burkina Faso.

Biological control, cowpea pod-sucking bug, egg parasitoid, functional response, mass production