Big Isle macadamia
growers are warned
of new pest

The state Department of Agriculture is warning about 650 macadamia growers that a new insect has been discovered in South Kona that could damage the state macadamia crop.

The insect, called the macadamia felted coccid, is a type of plant pest called a scale insect, so named because it creates a wax scale and then lives under it. This particular insect lives only on macadamia trees, according to the department.

The coccid has piercing, sucking mouth parts that are inserted into the plant, resulting in yellowing of leaves and decay and death of plant tissues, the department said.

In mature trees, infestation by the insect reduces nut production and delays the maturity of remaining nuts.

Macadamias are the fourth-largest agricultural commodity in the state, with annual sales of more than $32 million.

Newly hatched coccids are so small that they can be dispersed by the wind or carried by birds and ants.

They can also be carried on any moving surface, such as a person, a car or farm equipment.

Adult males have wings and look like gnats, the department said.

The coccid was discovered recently and collected for study on Feb. 25. Agencies of the University of Hawaii and the U.S. Department of Agriculture in Maryland are studying the insect.

One method of control already being used is a horticultural oil that has proved safe and effective in the macadamia's home country, Australia.

The use of predatory insects is also possible, according to the department.