Recent work on the mealybug vectors on cocoa swollen shoot virus.
Since 1969, work at Tafo, Ghana, on the mealybug vectors of swollen shoot virus of cacao has been concerned with obtaining more information on the basic biology of the main vector species (Planococcoides njalensis (Laing) and Planococcus citri (Risso)), especially on their population dynamics, on the inter-relations between mealybugs and other insect species associated with cacao and on the screening of cacao varieties for resistance to mealybugs. New measurements of age specific reproductive and mortality rates have led to simplified computer simulation. The regulating effect of parasites on the annual population cycle is discussed. The inter-relations of mealybugs with other insects have been investigated using multivariate statistical methods.