Effects of releases of the egg parasitoids gryon fulviventre crawford (hymenoptera: scelionidae) on clavigralla tomentosicollis stal. (hemiptera: coreidae), a cowpea pod-sucking bug, in a controlled environment

Clavigrallatomentosicollis Stal. (Hemiptera: Coreidae), major cowpea pod-sucking bug, causes significant economic losses. In the search for an alternative to chemicalcontrol, the use of the egg parasitoid G. fulviventre is a possibility. Given that no release strategy for G. fulviventre has yet been tested, it would seem wise, before considering large-scale use of this parasitoid, to determine an optimum release frequency. The mainof this study is to find an optimal frequency of parasitoid release. To this end, artificial infestations were carried outin a semi-controlled environment at the Centre for Environmental, Agricultural Research and Training of Kamboinse (Burkina Faso). A single release of the pest was carried outwith five release frequencies of the parasitoid. The results showed that the rate of parasitism was higher (64.57 ±4.76%) in successive releases of the parasitoid spaced one week apart and lower (42.72 ±4.99 %)in the single release.Pods were almost completely damaged without parasitoid release (91.83±1.74 %) and less damaged with successive releases (24.58 ± 1.59%). Parasitism rates did not differ significantly between two, three or four successive releases. This study is a first on the release of G. fulviventre in Burkina Faso and the results are of great importance for the implementation of an integrated management strategy of C. tomentosicollis.