Abstract
An outbreak of Mononychellus tanajoa (Bondar), Phenacoccus manihoti Matile-Ferrero since early 1979 is described on cassava in south-western Nigeria. Both species are believed to be newly reported from Nigeria. Late-planted crops were the most severely attacked. The coccinellids Exochomus flavipes (Thnb.) and Hyperaspis pumila Muls. were found in association with P. manihoti wherever it occurred, and may have been preying on the mealybug
