Rhizoecus root mealybug

Bustillo, Alex, 2015, Part II. Pests, Compendium of Coffee Diseases and Pests, United States of America: The American Phytopathological Society, pp. 45-60 : 50-51

The Rhizoecus root mealybug , Neorhizoecus coffeae (Laing) ( Hemiptera : Pseudococcidae ),

is widely distributed in Central and South America. The adult female root mealybug is snow white and has an elongated oval shape up to about 2.3 mm long

The life cycle from egg, to crawler, to nymph, to adult is about 60-120 days. The adult female lives for 27-57 days and can give birth to 17- 83 young. White, cottony-like masses containing egg-laying females, eggs. or both are normally visible on the outside of the root mass when an infested plant is lifted from the soil. Eggs hatch less than 24 h after being laid. Once crawlers find a suitable root, they settle down and begin to feed with their sucking mouthparts, especially on the secondary roots. The Rhizoecus root mealybug is known to spread by crawlers moving from infested plants to other plants.

Damage

Damage by the Rhizoecus root mealybug is nonspecific in that the most common symptoms are slow plant growth, lack of vigor, and subsequent death. The Rhizoecus root mealybug is not evident unless the root ball is examined by removing the plant. A white waxy substance and adult females are noticeable on the roots.

Population Management

N. coffeae has mutualistic associations with the ant Acropyga fuhrmanní (Forel), which is about 2 mm long. The ant protects and transports the mealybug from one root to nearby roots when necessary. The ant rubs the mealybug abdomen and gets the honeydew secretion, which it uses as food. There are no known natural predators of Neorhízoecus spp. Because the Rhizoecus root mealybug is very difficult to detect and control, every effort should be made to prevent its spread and establishment. Before planting coffee trees. the field site should be inspected for the presence of mealybugs. Similarly, roots of newly purchased plants must be examined by removing the pots or bags. In the field. roots of suspected plants, especially slow-growing ones, have to be checked. Alternate hosts must be removed or treated.