CONTROL OF ZONOCERUS-VARIEGATUS BY ULTRA-LOW VOLUME APPLICATION OF ANOIL FORMULATION OF METARHIZIUM-FLAVOVIRIDE CONIDIA

An oil-based formulation of Metarhizium flavoviride conidia, applied a t 2 X 10(12) spores ha(-1) in 11 ha(-1) gave good control of Zonocerus variegatus in 1-ha plots in southern Benin. In a three-replicate, ran domized, complete block (RCB) trial in Mono province, a significant re duction in insect counts between treated and control plots was observe d 10-15 days after application; treatment reduced the population by ab out 90%. A four-replicate RCB trial in Oueme province also gave high m ortality. Although a significant difference between treated and untrea ted plots was observed 10-18 days after application, insect dispersal out of cassava fields towards oviposition sites interfered with a clea r demonstration of control. Significantly more Z. variegatus cadavers with M. flavoviride infection were found in treated plots than control plots.