Forest Preserve District of Cook County, Illinois
Nature Bulletins
Newton Home Page

Introduction and Instructions

Search Engine

Table of Contents



The Japanese Beetle
Nature Bulletin No. 579   November 7, 1959
Forest Preserve District of Cook County
Daniel Ryan, President
Roberts Mann, Conservation Editor
David H. Thompson, Senior Naturalist

The deadly warfare between mankind and the insects never ends. Every minute of the day and night, billions of them are attacking our crops, orchards, forests and grasslands. They attack our homes, gardens, and even ourselves. Of those that were inadvertently brought to the United States from foreign countries, one of the most destructive is the Japanese Beetle.

This pest was discovered in a nursery near Riverton, New Jersey, in 1916. Evidently some of its grubs -- the larvae-- had arrived a few years earlier in earth around the roots of plants imported from Japan. Over there, native parasites keep this beetle under control. Here, with none of those natural enemies, it multiplied and spread rapidly. Also, before we established stringent preventive measures, it was widely distributed in shipments of nursery and greenhouse plants. Now it hitchhikes on railroad trains and airplanes. Except northern New England, all but three states east of the Great Plains are infested by the Japanese beetle.

The adults feed voraciously on more than 250 kinds of plants They attack shade trees; the foliage and fruit in orchards; ornamental plants such as roses the fruits of berry vines; wild and cultivated grapes; the leaves of clover, alfalfa and soybeans; the silk on ears of green corn. The grubs destroy the roots of grasses in lawns, golf courses, pastures and hayfields. Each year, in damage done and efforts to eradicate it, this insect costs us many millions of dollars.

The Japanese beetle is closely related to the sacred scarab beetle of Egypt and to the June bug and "tumble bug" in America. The adult has a plump, shiny green body a half-inch long, and copper-colored wing covers. There are two white spots on the end of its abdomen and five more on each side. In our region they appear about the last week in June and live from 30 to 40 days. The female deposits four or more eggs in each of many shallow burrows she digs in the ground. These hatch into small white grubs that feed on plant roots and grow rapidly until, in late autumn, they burrow deeper and hibernate. As soon as the soil becomes warm in spring, they come up near the surface and continue to feed and grow until nearly an inch long. Then they go into a resting or pupa stage for 3 or 4 weeks, become adults, and finally emerge. Frequently there are from 50 to 150 grubs per square foot of soil and they devastate large areas.

In Illinois the first serious infestation occurred near Bessemer Park on the south side of Chicago in 1936. There, and in later outbreaks at Highland Park, Evanston, Forest View, Decatur and East St. Louis, the beetles were eradicated. Last year, an area which extended from 119th St. to Sibley Blvd. and from Crawford Ave. to the Illinois Central RR., including our Pipe O' Peace golf course and other forest preserve holdings, was found badly infested This spring the beetles were eradicated by the Illinois Dept. of Agriculture in cooperation with the federal government and the Forest Preserve District. This summer, however, Japanese beetles were found east of the I. C. RR.; in railroad yards at Joliet, Streator, Mattoon and East Peoria; and an area of about 45, 000 acres near Sheldon, Iroquois county, is seriously infested.

Biological controls of this beetle -- by parasitic wasps and flies, by round worms, and by bacteria which infect the grubs with "milky disease" have proven ineffective or too costly Insecticides such as lead arsenate, DDT, chlordane, and dieldrin have been used extensively. The latest, cheapest and most effective method is to spread over an area, by airplane and at the rate of two pounds per acre, small granules of a toxicant called Heptachlor, They dissolve into the soil, kill the grubs, and eradicate this destructive pest.

To return to the Nature Bulletins Click Here!
Hosted by NEWTON

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Sponsered by Argonne National Labs