Insect Control: Houseplants

Mealybug

Mealybug
Tap to view larger image
 
Mealybug are usually found in moist, warm climates. They are considered pests as they feed on plant juices of greenhouse plants, house plants and subtropical trees.

Mealybug females feed on plant sap, normally in roots or other crevices. They attach themselves to the plant and secrete a powdery wax layer (therefore the name mealybug) used for protection while they suck the plant juices. The males on the other hand, are short-lived as they do not feed at all as adults and only live to fertilize the females. Male citrus mealy bugs fly to the females and resemble fluffy gnats.

The most serious pests are mealybugs that feed on citrus; other species damage sugarcane, grapes, pineapple, coffee trees, cassava, ferns, cacti, gardenias and orchids. Mealybugs only tend to be serious pests in the presence of ants because the ants protect them from predators and parasites. Mealybugs also infest some species of carnivorous plant such as Sarracenia (pitcher plants), in such cases it is difficult to eradicate them without repeated applications of insecticide. Small infestations may not inflict significant damage. In larger amounts though, they can induce leaf drop.

The papaya mealybug feeds on the sap of plants by inserting its stylets into the epidermis of the leaf,as well as into the fruit and stem. In doing so, it injects a toxic substance into the leaves. The result is chlorosis, plant stunting, leaf deformation, early leaf and fruit drop, a heavy buildup of honeydew, and death. Heavy infestations are capable of rendering fruit inedible due to the buildup of thick white wax. Papaya mealybug has only been recorded feeding on areas of the host plant that are above ground, namely the leaves and fruits.