Japanese Beetles


The Japanese beetle (Popillia japonica Newman) is a highly destructive plant pest of foreign origin. It was first found in the United States in a nursery in southern New Jersey over 80 years ago. In its native Japan, where the beetle's natural enemies keep its populations in check, this insect is not a serious plant pest.

Both as adults and as grubs (the larval stage), Japanese beetles are destructive plant pests. Adults feed on the foliage and fruits of several hundred species of fruit trees, ornamental trees, shrubs, vines, and field and vegetable crops. Adults usually feed in groups, starting at the top of a plant and work downward, with a preference for plants exposed to direct sunlight. A single beetle does not eat much; it is group feeding by many beetles that causes the severe damage. Adults feed on the upper surface of foliage, chewing out tissues between the veins. This gives the leaf a characteristic skeletonized appearance. They tend to do little feeding on thick, tough leaves.
The grubs develop in the soil, feeding on the roots of various plants and grasses and often destroying turf in lawns, parks, golf courses, and pastures.

The spread of the Japanese beetle infestation is primarily the result of flight by the adults. They can fly as far as five miles, but one to two miles is more likely. Usually, they make only short flights as they move about to feed. Local infestations spread as beetles move to favored food and suitable sites for egg laying.


Life Cycle: 

In late June and early July, Japanese beetle adults emerge from the ground and begin to search for food and mates. The adults can fly as far as a mile or more and feed on a multitude of plants; their favorites include roses, grapes, and linden trees. Other scarab beetles may go unnoticed at this time because they are not attacking ornamental plants.

In July, female beetles spend 2–3 weeks laying up to 60 eggs in the soil. Depending on soil moisture and temperature, eggs hatch about 2 weeks later. These first-stage ("first-instar ") grubs feed on grass roots for most of August. The grubs are small, feeding close to the surface, and vulnerable to biological and chemical insecticides at this time. Control high populations at this stage, before feeding on turf roots is noticeable.

From late August through October (depending on your climate) grubs molt into a second and then a third stage. As they grow, grubs consume more roots. Damaged turf often appears now.
As temperatures drop in autumn, grubs move down in the soil. They overwinter as third-instar grubs below the frost line.

In the spring Japanese beetle moves up in the soil to feed on roots for a very short time. (Most of the lawn damage seen in the spring is a result of fall feeding, not spring feeding.) In late spring grubs stop feeding and turn into pupae that are resistant to insecticides. In late June or early July, beetles emerge from the pupae and crawl out of the soil, completing the cycle. foliage for cover.


Symptoms of damaged lawns:
Severe grub damage in a lawn appears as large, irregular sections of brown turf that detach from the soil without effort. Unlike turf damaged by drought or excessive fertilizer, the turf peels away like a carpet being rolled up.


Recommended Control Methods:


Japanese Beetle Traps:
For Maximum effectiveness, use the suggested number of traps listed below:
Less than 1/8 Acre: 1 trap
1/8 to 1/4 Acre: 2 traps
1/4 to 1/2 Acre: 3 traps
1/2 Acre: 4 traps
Over 1/2 Acre: * * Trap every 150' to 200 ' along perimeter



Biological:
Milky Spore--Milky spore is the common name for spores of the bacterium Bacillus popillae. Milky spore disease builds up in turf slowly (over 2-4 years) as grubs ingest the spores, become infected, and die, each releasing 1-2 billion spores back into the soil.



Chemical Control:
Scotts® GrubEx® Season-Long 
Kills grubs before they damage your lawn. Just one application protects from grubs all season long.
Sevin® Brand Insecticide 
Sevin is one of the most effective and recommended insecticides to use for control of damaging, adult Japanese beetles. Sevin is also very effective in the control of ticks that transmit Lyme disease.