Planococcus citri

SPECIES: Planococcus citri ( Order Rincoti )

COMMON NAME: Mealybug or citrus scale insect

SIZE: da 2,5 a 3 mm

LIFECYCLE: Planococcus citri normally overwinters as a 2nd instar nymph; however, it can also overwinter in other stages, sheltered among vegetation or between cracks in the trunk, or at the base of the collar. In spring, females begin oviposition, which occurs in an ovisac formed by flakes of wax; this ovisac takes on a cottony appearance and can contain several hundred eggs (even 600). The number of generations varies depending on environmental conditions; it usually varies from 2 to 5 generations per year.

FEATURES: The mealybug is a polyphagous species widespread throughout temperate areas, in open fields and in greenhouses; it attacks citrus fruits, causing damage in particular to oranges, mandarins and lemons. The adult female (about 2.5-3 mm long) is flattened and has a body covered in a waxy powder; it is surrounded by a series of waxy rays of equal length, with the exception of the two caudal ones, which are longer. The male, 1 mm long, has wings and a reddish-brown body. The nymphs, about 0.5-1 mm long when mature, are yellowish. 

HABITAT: On citrus fruits it is located near the fruits, especially in the contact areas between fruits and fruits/leaves; the thick vegetation favors the formation of dense flocculous colonies, sometimes also present on the flowers, which proliferate in conditions of high humidity and in shaded areas.

DAMAGE: Damage can be direct (symph removal) or indirect (production of honeydew and abundant waxy secretion, with consequent development of sooty mold).

The fruits are depreciated because they are smeared with honeydew, covered with sooty mold and wax flakes; heavy infestations also cause the fruits to fall. The attack of Planococcus citri favors the presence of other insects including the larvae of the Lepidoptera Phycitid Cryptoblabes gnidiella that find refuge among the waxy masses; these larvae damage the flowers and fruits.