Boxelder Bug (Leptocoris trivittatus)
Injury: The Boxelder bug may be a pest both of outdoor trees as well as a household nuisance. It is the latter that is of most concern to homeowners. The bugs overwinter as adults in protected dry places, often in wall voids or attics of houses and buildings. During warm days in the fall and spring the bugs become active and invade homes becoming an extreme nuisance.
Description: The adult boxelder bug is about ½ inch in length and brownish-black in color with red stripes on the thorax and wing margins. The body is also bright red. Eggs are a rusty red color and are not often seen as they are deposited on boxelder trees. The nymphs, also found on the trees, are bright red in color with the head end darker. Nymphs resemble adults but do not have fully developed wings and are not able to reproduce. The change from nymph to adult is a gradual one.
Life History: The boxelder bugs pass the winter in the adult stage in dry, sheltered places where they have accumulated in gregarious masses. They often choose buildings or houses as a protected place to overwinter. When weather warms up in the spring, the bugs leave their places of hibernation to fly to boxelder trees where they deposit their eggs. Eggs are usually deposited in bark crevices and hatch in 11 to 14 days. The nymphs feed by inserting their beaks into leaves, fruits or soft seeds and sucking the plant juices. Feeding continues throughout the summer and the nymphs gradually mature becoming adults as cold weather approaches in the fall. In some areas there may be two broods of this insect, one reaching maturity in mid-summer and the second one in early fall.
Management: Since the presence of these bugs is associated with boxelder trees, replacement with other tree species is one method of eliminating the nuisance pest. If boxelder is grown, it may be best to keep only the male or staminate trees which would help to reduce its numbers.
Out of doors insecticides have been used effectively on the trees to control the nymphs while they are actively feeding. Either the insecticide malathion or carbaryl (Sevin) may be recommended. BE SURE TO FOLLOW THE MANUFACTURERS DIRECTIONS ACCURATLY WHEN USING ANY PESTICIDE. A small number of trees may be sprayed by the homeowner, but large trees and large groups of trees should be done by a certified pesticide applicator. Cyfluthrin of deltametrin may be used outdoors to spot treat accumulations of boxelder bugs.
Indoors vacuuming up the bugs and discarding the contents of the vacuum bag when finished is a good effective housekeeping method. (If bugs are left inside the vacuum they may crawl out in the storage place.) Tightening up the routes of entry the bugs use by caulking or screening is a more permanent solution.
Prepared by Carolyn Klass, Senior Extension Associate Department of Entomology
Note: This is a Home Remedy. An 80/20 mix of water and liquid dish soap sprayed onto the bugs works well.
Every effort has been made to provide correct, complete, and up-to-date pesticide recommendation in this publication. Nevertheless, changes in pesticide regulations occur constantly, and human errors are still possible. These recommendations are not a substitute for pesticide labeling. Please read the label before applying any pesticide.
Disclaimer: Cornell Cooperative Extension and its employees assume no liability for the effectiveness or
results of any chemicals for pesticide usage. No endorsement of products is made or implied.