Bugs That Smell Like Grass
Western conifer seed bugs (Leptoglossus occidentalis) are native to the Pacific northwest, but have since spread out to establish themselves across most of North America, with the exception of the southern and Gulf states. These bugs often come up against humans when they enter buildings, looking for a warm place to spend the winter. Handling them, or squashing them, causes them to release an odor that some people think smells like apples, pine or fresh-cut grass. Does this Spark an idea?
-
Description
-
Western conifer seed bugs belong to the leaf-footed bug family (Coreidae). Like other bugs in this family, their hind legs are wide and flat like a leaf. Their brown wings cover a yellow or orange abdomen with five black patches, which can be seen when they fly. Western conifer seed bugs grow to be about 3/4 inch long and have long antennae. They make a loud buzzing sound when they fly. Nymphs are orange when they hatch but turn reddish-brown after several molts.
Damage
-
Nymphs and adult bugs feed on green pine cone sap, causing them to wither and fall off the tree without ripening. They also feed on the seeds and sometimes the twigs and needles of conifers, including white and red pine, Scots pine, Austrian pine, mugo pine, Douglas fir and hemlock. Although they don't cause much damage to growing trees, their feeding results in a loss of seed crop. Western conifer seed bugs are also nuisance pests when they invade homes, looking for shelter from the winter. These bugs don't bite or sting, and they don't damage household items or breed indoors, but people don't like them in their homes.
-
Life Cycle
-
Female bugs lay rows of eggs on host conifers in the spring. Eggs hatch in 10 days and the nymphs start feeding on cone scales. Young bugs molt several times as they develop, and reach maturity in late August. Adult bugs feed until the weather turns cold, when they look for a place to overwinter. In addition to human structures, bugs may overwinter in dead and dry Douglas firs, under pine bark and in rodent nests. A single generation is produced each year.
Control
-
There are no pesticides registered to use against western conifer seed bugs. The best way to control them is to mechanically exclude them from your house. Screen attic and wall vents, chimneys and fireplaces. Caulk gaps around window frames, doors and chimneys. Vacuum up bugs that have already invaded your home.
-
References
Resources
- Photo Credit Jupiterimages/Photos.com/Getty Images
