-
Step 1
What do Japanese beetles look like?- Adult Japanese beetles are metallic green color, oval, and about 3/8 to ½ an inch long, and about ¼ inch wide. The wing covers are copper brown, and their abdomen has a row of five tufts of white hairs on each side.
Where do Japanese beetles come from and what will they do?- Japanese beetles are the adult stage of grubs in the soil (one of many types of grubs). They emerge from the ground and begin to feed on plants sometime in June. They feed on over 400 species of leafy plants, eating leaves, flowers, and sometimes the fruit. They are most active during the warmer parts of the day and especially active on warm, clear, sunny days. Activity usually lasts about 4-6 weeks, after which the beetles gradually die off. (Individual beetles live about 30-45 days.) After mating, females lay their eggs in the turf, which hatch into grubs, and feed on turf roots in the soil until cold weather drives them deeper into the soil. They move back to the top when temperatures warm (spring), and emerge as adults the following June.
One beetle does little damage, but they usually feed in groups, starting at the top of a plant and working down, and group feeding can cause severe damage. Early arrivals release a hormone, which attracts other adults to the plants. Females also release an additional sex pheromone to attract males. Odors released from beetle-damaged leaves also assists in attracting beetles to a particular plant. And, although Japanese beetle damage looks devastating, their feeding rarely kills woody plants. (Note: Although adult beetles typically only make short flights as they move about to feed or lay eggs, they are extremely mobile and have been known to fly as far as 5 miles.) -
Step 2
How do I control Japanese beetles? - Cultural Controls: Don’t plant trees and shrubs that Japanese beetles like. Japanese and Norway maples, birch, pin oak, rose of Sharon, sycamore, ornamental apples, plums and cherries, roses, willows, lindens, hollyhock, sassafras, grapes, filbert, even poison ivy are a few of their favorite plants. If you do, just be prepared for ‘possible’ Japanese beetles. Physical Removal: Removing them by hand, keeping lower populations, and not allowing beetles to accumulate (beetles attract beetles) will help. Hand picking, hosing them off (especially early on), or shaking them off the plant (in a bucket of soapy water) early in the morning when the insects are sluggish works great. Highly valued plants could be covered with cheesecloth, grow covers, or fine netting during the peek of beetle activity. Chemical Controls: Many insecticides are labeled for use against Japanese beetle adults. If you do take this route, 1.) Thoroughly treat foliage and flowers, 2.) Use spreader sticker to increase duration of effectiveness, 3.) Repeated sprayings may be needed (check labels), 4.) Do not spray when bees are active, 5.) Insecticidal soaps will kill adults hit by the spray, but provide no residual protection, 6.) If spraying edibles, check labels for any restrictions. Insecticides for adult beetles include Eight, Captain Jacks Deadbug Brew, Sevin, Orthene, Rotenone / Pyrethrum sprays, Insecticidal Soaps, Neem Oil (used as a repellent as well), and Merit (if applied to plants 3 weeks in advance, and it will need assistance with other foliar sprays in heavy populations).
-
Step 3
Natural Control: Birds such as grackles, cardinals and larger birds will feed on the adult beetles.
-
Step 4
Mechanical Control -Trapping: There are several types of Japanese beetle traps, with both a floral / food lure and a sex pheromone lure, and can draw in thousands of beetles each day. Research has shown these traps actually attract more beetles than are caught. Susceptible plants may be along the flight path of the beetles, and could suffer more than if no traps had been used at all. If using traps, place them well away from gardens and landscape plants - maybe in the neighbor’s yard!
-
Step 5
Note: Because beetles are attracted to favorable plants from a considerable distance, controlling grubs in the lawn will not protect landscape plants from adult feeding.
For more information visit www.natorp.com.
Comments
sherriruston said
on 7/16/2009 Great introductory info..to help me understand their life-cycle. I'm reconsidering using the trap my hubbie bought for me.