Observation of the damage caused by Mussidia nigrivenella (Pyralidae) on corn cobs and cotton bolls begun in Togo in 1988 was continued in 1990 and 1991. The study was conducted at IRCT's Anié-Mono station at the Dalanda, Notsé and Kouvé test and on small holdings in the Notsé region. M. nigrivenella is the main pest on corn (over 90% of the caterpillars observed). Its larvae populations were higher in 1991 than in the previous year, owing to favourable climatic and cropping conditions.
On immature cotton bolls, C. leucotreta remains the dominant species. However, the extent of M. nigrivenella activity on mature bolls was revealed for the first time. In certain locations, over 90% of the caterpillars and chrysalids observed in attacked mature bolls belong to this species. Hence, cotton plants which are not destroyed after harvests can act as reservoirs for pyralid pests.
