NATURAL LEVELS OF FUNGAL-INFECTIONS IN GRASSHOPPERS IN NORTHERN BENIN

The infection of grasshoppers by naturally occurring, entomopathogenic fungi was monitored at two sites in Malanville, northern Benin, Afric a. Grasshoppers were collected and recorded from the sites between Jun e and December 1992 and all of them, barring the first instars, were i ncubated in ventilated cages. At the first site, 1343 individuals of 3 5 grasshopper species were incubated, and at the second site, 857 indi viduals of 36 grasshopper species were incubated Three hyphomycete fun gi (Deuteromycotina: Hyphomycetes), Metarhizium flavoviride Gams and R ozsypal, Beauveria bassiana (Bals.) Vuillemin and Sorosporella sp, wer e found infecting grasshoppers. The average incidence of M. flavovirid e infection was 2.9% and 1.8% at the two sites for all host species. M . flavoviride sporulated on most grasshopper cadavers within 10 days o f collection. B. bassiana and Sorosporella sp. were only collected fro m one and five grasshopper individuals respectively. A significant dif ference was noted in the time to death of small grasshopper species in fected with M. flavoviride compared to larger species. At one site, M. flavoviride infection was positively correlated with rainfall during the 10-day period in which samples were taken.