Planococcus citri (Risso)

Bustillo, Alex, 2015, Part II. Pests, Compendium of Coffee Diseases and Pests, United States of America: The American Phytopathological Society, pp. 45-60 : 51

Planococcus citri (Risso) ( Hemiptera : Pseudococcidae )

is one of the most common mealybugs and it is present in nearly all coffee-growing countries. It mainly attacks the aerial part of the plant. The species P. lilacinus (Cockerell) and P. minor (Maskell) are restricted to Asia, and similar species, P. kenyae (Le Pelley) and P. fungicola Watson & Cox , are only in Africa. Male citrus mealybugs have four nymphal stages. Nymphs are yellow and mobile. The first nymphal stage lasts an average of 9.9 days; the second, 8.7 days; the third, 2.5 days; and the fourth, 3 days. Female citrus mealybugs have only three nymphal stages. The first nymphal stage lasts an average of 11.5 days; the second, 8.2 days; and the third, 8.4 days. Male mealybugs live for 2-4 days after the final nymphal molt. Females live for an average of 87.6 days as adults and may start laying eggs 15-26 days into their adult life. Females lay 200-400 eggs in a life ­ time. The sex ratio of females to males is approximately equal. Eggs are laid in groups, covered by ovisac wax threads. Eggs are yellow, hatch in 2-5 days, and are cylindrical to ovoid. The citrus mealybug is capable of active movement throughout its life.

Damage

On coffee plantations, nymphs and adults form large aggre ­ gates around the cluster of berries and in the new foliage of the upper third of the trees. Feeding causes yellowing of the plant organs and wilting. In addition to the honeydew secretions, a sooty mold develops, which interferes with the plant photosynthesis. Although the citrus mealybug is not a great honeydew producer, several ant species tend them. Damage is generally increased in severity when the citrus mealybug is associated with ants. The most common tending ant species is Anoplolepis longipes (Jerdon) .

Population Management

There are numerous parasitic wasps that attack the citrus mealybug and several predatory beetles. The most common natural controls are the parasitoid Leptomastix dactylopii Howard and the predator Cryptolaemus montrouzieri Mulsant. Pathogenic fungi also attack this pest. Controlling the tending ants helps reduce the citrus mealybug populations.