Asian Longhorned Beetle Found in Chicago

FOR IMMEDIATE RELEASE
July 17, 1998

Asian longhorned beetle, Anoplophora glabripennis, has been discovered in a small area of Chicago. It is located in a six square block area in the Ravenswood area of Chicago. This insect is native to China, Korea, and Japan. The lattitude of its distribution in the Far East corresponds in North America as running from Cancun, Mexico to Milwaukee, Wisconsin. The only other place where it has been found in trees in North America is in Amityville and Brooklyn, New York, both on Long Island, where it was found in August, 1996.

Asian longhorned beetle tunnels into not only dead and dying trees, but also attacks apparently healthy trees. It prefers maple, poplar, and willow, but also attacks horse chestnut, mulberry, plum, pear, black locust, elm, chinaberry, citrus, birch, and rose of Sharon. Among the maples, Norway, sugar, silver, and sycamore maple are the most common hosts. Adult Asian longhorned beetles are shiny black and about one inch long with about 40 irregular sized and shaped white dots on the wing covers. They have long antennae that are at least as long as the body and black and white banded. Adults are present from August through October in China, peaking in July. They have been reported as early as mid-May by New York residents.

Adult beetles feed on the bark of twigs and small branches after emerging. They may migrate as much as six-tenths of a mile in search of host trees. Females chew a three-eighths inch diameter pit through the bark and then lay an egg in each pit. Individual adults live for several weeks with each female laying 25 to 32 eggs. The hatching larva tunnels just under the bark in the cambium. Older larvae tunnel deep into the tree at an upwards angle with larval tunnels being four to six inches long. Larvae push frass consisting of wood fibers and feces out of the tunnels. This results in piles of sawdust below active tunnels. The larvae spend the winter deep in the tree, tunneling and feeding again in the spring before pupating in late spring or summer in the larval tunnel. Adults emerge from the tree through one-quarter to one-half inch round holes. Most life cycles last one year, although some last for two years.

Damage consists mainly of weakened branches that break off during heavy winds. Attack for several years could cause the death of branches, limbs, or entire trees. Although many insect borers and the yellow-bellied sapsucker make one-quarter inch diameter holes in trees, emergence holes approaching one half inch are uncommon. Cottonwood borer makes this size of hole in cottonwood and other poplars, but it is uncommon in Illinois. Carpenter bees make holes this big, but normally attack lumber or the cut end of logs. The shallow egg-laying holes made by the females are similar to those made by woodpeckers searching for insect larvae in or under the bark. However, these beetles make round holes that are similar in diameter whereas woodpeckers tend to make jagged holes of various sizes.

Control is difficult due to the extended adult emergence period. Insecticide treatment would involve several applications, is not practical and may not be very effective. This beetle is eliminated in infested areas by cutting down all infested trees and chipping or burning them. Areas where the beetle is found are placed under quarantine that prohibits the movement of host species firewood, logs, green lumber, stumps, roots, branches, and debris of one-half inch or more in thickness out of the area.

Beetles or wood with likely damage should be submitted to the Plant Clinic, 1401 St. Marys Road, Urbana, IL 61802 or your local Extension office for their forwarding to the Plant Clinic for postitive identification.

Follow these links for additional photos or a video of the Asian Longhorned Beetle.

Source: Philip Nixon, Extension Entomologist

Photographs on this page by Charles Harrington/Cornell University. Visit Cornell University's site on the Asian Longhorned Beetle.