Surendra K. Dara, Chris J. Lomer, Fabien C.C. Hountondji and J. Steve Yaninek
Seasonal incidence of two fungal pathogens, Neozygites floridana (Weiser and Muma) (Zygomycotina: Zygomycetes) and Hirsutella thompsonii Fisher (Deuteromycotina: Hyphomycetes), in populations of two species of mites, Mononychellus tanajoa (Bondar) and Oligonychus gossypii (Zacher) (Acari: Tetranychidae), on cassava was monitored in Benin for one fall year from November, 1996. Out of the 14 surveyed locations that spread across the four agroecological zones, N. floridana and H. thompsonii were found in 11 and 10 locations, respectively. While both of them were present in 8 locations, none was observed in one location. In general, the level of infection was low and the pathogens did not appear to show any trend specific to any agroecological zone. When results from all the locations were combined, a maximum of about 1% infection was found in M. tanajoa by each of the pathogens. However, O. gossypii had a maximum of 11 % infection by N. floridana and close to 1% by H. thompsonii. Resting spores of N. floridana, which were never reported to be found in Benin, were seen almost throughout the observation period in one location or the other in both species of mites. In general, populations of M. tanajoa were more on young leaves than on old leaves, while those of O. gossypii were more on old leaves than on young leaves.