Japanese beetles are staging their annual invasion
By Darrell Blackwelder
For the Salisbury Post
Sporadic rainfall has softened our hard clay soil, allowing Japanese beetle adults the opportunity to emerge and pillage our plants.
Reports of the pests already damaging ornamentals, fruits and vegetables throughout the county are already coming in.
Japanese beetles have a wide host range, feeding on more than 275 different types of trees, shrubs and vegetable plants. The beetle’s favorite foods seem to be roses, grape foliage, peaches and plums, along with okra and corn silks.
One of the most recognizable insects, the Japanese beetle, is oval and just under half an inch long, with a metallic green body and copper-colored wings.
They usually feed in groups, easily devouring a rose bud or cherry leaf. Often, when disturbed, the insect plays dead for a few seconds and then flies away slowly in a circular motion.
The Japanese beetle female has a short life span of about 45 days but is very productive, laying about 60 eggs on turf or sod. When the eggs hatch, the larvae feed on sod roots. An indication of severe infestation is large, dead patches of turf.
The larvae burrow 10 inches into the soil and pupate, hatching in late spring to initiate another life cycle. The beetle usually emerges in the summer when a shower or irrigation softens the soil for easy emergence.
A regular spray program is one method of controlling the beetle. Insecticides such as Sevin, which can be applied as a dust or a liquid, immediately control the insect, but this insecticide has a very short life and must be used each time the insect appears. Large populations of beetles may require applications on a daily basis.
Japanese beetle traps are often used as an alternative control method. These traps arw coupled with a pheromone (sex attractant) that draws the insect to the trap. The insect hits the bright yellow part of the trap and falls into a bag or a can for easy disposal.
Research has shown that Japanese beetles are attracted to bright colors, especially “John Deere” yellow.
Don’t place these traps near the plants you are trying to protect. In most instances, the traps attract the beetles to those very plants.
Hand picking the beetles is another method of control if the beetle population is not too large. Dropping the beetles into a container of kerosene is a very effective control method. In the late 1970s, milky spore was touted as an effective biological control method, but in some situations, its use has not proven to be effective, especially if the entire community is inundated.
Darrell Blackwelder is an agricultural agent in charge of horticulture with the North Carolina Cooperative Extension Service in Rowan County.