The infestation of stored potatoes (Solanum tuberosum) by Planococcus citri (Risso)(Homoptera:Pseudococcidae) on the Jos Plateau, Nigeria.
Planococcus citri (Risso) has been observed attacking stored potato tubers in several areas of the Jos Plateau, Nigeria, since 1962. A field survey in 1968 showed that infestation originated in the field; the mealybug was found in all the growing areas. The attack is heaviest on the sprouts of seed potatoes, which are stored for considerable periods, and affected sprouts shrivel and produce poor plants. Saliva injected into the tubers during feeding causes physiological damage and can result in secondary infections. Another mealybug, Aspidiella hartii (Ckll.) has been found attacking yams in parts of the northern States of Nigeria. It causes damage similar to that by P. citri but has not been found on potato. P. flagellatus De Lotto and Dysmicoccus brevipes (Ckll.) have been found on soy beans grown in the same areas as potatoes on the Jos Plateau.