Pineapple mealybug (Dysmicoccus brevipes)
The mealybugs are oval, pink in colour, up to 3 mm long, covered with a whitish waxy secretion, which develops into waxy filaments around the body. This mealybug is the most serious pest of pineapples, because it is a vector of the Mealybug or Pineapple Wilt Virus. The mealybug is common on the roots of pineapple and large colonies develop on the stems just above ground level.
The mealybugs may spread upwards to feed in the floral cavities, on both small and mature fruit, and on the crown leaves. Heavy infestations are conspicuous because of the white waxy adults, which often occur at the growing points, around the stem nodes, on the undersides of leaves, on the fruit and on the roots.
Feeding on leaves causes yellowing and drying up of the leaf-tips, which progresses towards the base of the leaves. Feeding in the blossom cavities causes wounds, which sometimes become contaminated by fungal spores resulting in a disorder called black spot. Feeding on roots is associated with the rotting of roots and subsequent wilting of the plant. "Smooth Cayenne" crowns used as planting material are frequently infested with mealybugs, and therefore new plantations usually become infested from the time of planting.
The bigheaded ant, Pheidole megacephala, is commonly associated with mealybug colonies. They do not attack the mealybugs but feed on the honeydew excreted by the mealybugs, preventing the formation of thick honeydew coats where crawlers (young mealybugs) may get entangled. Moreover, while feeding on honeydew, the ants interfere with the mealybug natural enemies. Thus, mealybug colonies thrive in presence of ants. Mealybug infestations may also be spread into new plantings by ants carrying the young mealybugs from one plant to another in their jaws.
- Control ants to give a chance to natural enemies to keep mealybugs under control.
- See also the section on pineapple wilt virus.