The cassava mealybugPhenacoccus manihotiMat‐Ferr is new to Sierra Leone where it has quickly achieved key pest status. It is firmly established in the Western Area of the country and is progressively extending to the provincial areas. All available cassava varieties are susceptible to the insect, and the damage is especially significant on the late planted crop. Biological control, for example by ground release of exotic hymenopteran parasitoids in the dry season, is recommended as a long lasting strategy to undermine the pest's status as a limiting factor to food production.