Influence of host density on the reproductive strategy of Cephalonomia stephanoderis, a parasitoid of the coffee berry borer

The effect of the density of the coffee berry borer, Hypothenemus hampei (C oleoptera: Scolytidae) on reproductive and host-feeding behaviours of the p arasitoid Cephalonomia stephanoderis (Hymenoptera: Bethylidae) was evaluate d under laboratory conditions. The number of hosts used for oviposition was density-dependent at low host density. Beyond a density of six hosts/day, the oviposition rate reached a maximum of 1.2 eggs/day due to egg limitatio n. Cephalonomia stephanoderis females responded to increasing host availabi lity with a linear increase in host feeding. Overall, parasitoids killed mo re coffee berry borers by feeding and paralysis than by parasitism. At low host density, the pre-oviposition phase was extended, oogenesis was delayed , more males were produced, and host feeding occasionally occurred concurre ntly with oviposition. We suggest that the efficacy of C. stephanoderis as a biological control agent depends on seasonal variations in host density. Inoculative vs inundative releases in coffee plantations are discussed in r elation to the abundance of the coffee berry borer during the fructificatio n and interharvest periods.