Stopping Japanese Beetles

Japanese beetles can be found in every state east of the Mississippi. The level of infestation in your area depends on prevention measures and a bit of luck! These beetles cause major damage to plants and grass, roots specifically. They are known to skeletonize leaves.

You’ve probably seen evidence of Japanese beetles at one time or another, especially if you have roses, which are a favorite target! You probably haven’t seen them yet this season. They prefer temperatures above 85 degrees Fahrenheit. Once they are in your yard, others will join, because they emit a pheromone into the air that attracts more beetles!

What do Japanese beetles look like?

You’ll probably recognize this beetle from the picture. Adults are a metallic blue-green with bronze wing covers and are about 1/2 inch long. Tiny hairs cover their body. The larvae are fat, white, and dirty. You may also hear these young beetles called white grubs. The babies have brown heads and are about 3/4 an inch long.

Why are they such a problem?

Adult beetles feed on the leaves and flowers of a variety of plants and have been known to completely defoliate the plants they attack. Adults also feed on fruits including grapes, raspberries, and plums. This is not good for the fruits, because once a beetle bites into it, the fruit is then open to disease.

Larvae feed on grass and garden plant roots. Root health is a means of preventing weeds and attaining greener fuller grass. So you can imagine the damage caused if the roots of grass and plants are compromised!

How do you prevent Japanese beetles?

You’re wondering how to prevent beetles and grubs from invading your outdoor spaces? Let’s start with the life cycle.

Spring is the time when overwintering larvae will move toward the soil surface and begin to feed on grass roots and organic matter. They pupate in early summer, then the adults emerge ready to chow down! Late summer is when they will lay eggs, and those eggs will hatch into larvae and overwinter until the next spring.

The easiest way to get rid of a small amount of adult Japanese beetles is to drown them in soapy dishwater. Go out in the morning and knock the beetles off into a bucket of soapy water. You can also spray the plants lightly with a soapy mixture, but this will only get rid of the beetles at that moment, not prevent future attacks. There are pesticides that target the beetles. Look for Carbaryl, acephate, and permethrin on the label. The organic, neem-based pesticides can also provide control. Don’t invest in the bug traps, they tend to attract more than they kill.

The larvae can be trickier to get rid of since you can’t see them. One way to get rid of them is to apply parasitic nematodes, which prey on grubs. Apply in late August or early September, and make sure that the nematode product is fresh and soil is kept moist after application.

Do you need help conquering this pest? Call Pure Green today!