| 
			
			 Boxelder bugs are commonly found trying to enter 
			houses, especially if there’s a boxelder tree nearby. These insects 
			are about one-half inch long and black with orange or red markings. 
			During the spring and summer, the adults will feed on leaves and 
			seeds of boxelder trees (and occasionally maple and ash trees). When 
			temperatures begin to cool in the fall, they will begin to seek out 
			warmer areas. 
 “They are most often attracted to buildings with large southern or 
			western exposures, because they are warmer than the surrounding 
			area,” Johnson says. As they aggregate on a building, they will find 
			cracks and other spaces to squeeze into, occasionally making their 
			way indoors and ending up in walls and attics until warm weather 
			returns.
 
			
			 
			Multicolored Asian lady beetles are also commonly found attempting 
			to make their way into homes. According to Johnson, these lady 
			beetles were introduced into the United States to control aphids on 
			pecan trees. Since their introduction, they have spread throughout 
			the country. The beetles vary in color from yellow to reddish-orange 
			and have anywhere from zero to 19 spots. They can often be 
			distinguished from other lady beetles by the presence of an ‘M’ 
			pattern near their head. In their native China, they will overwinter 
			on tall cliffs. “Since we lack these in most parts of Illinois, they 
			will instead use buildings to overwinter,” Johnson says. 
 The brown marmorated stink bug (BSMB), on the rise in Illinois, is 
			the final home invader. This stink bug is native to Asia and was 
			first discovered in the U.S. in the late 1990s in Pennsylvania. 
			Since then, Johnson says, it has quickly spread throughout the 
			country. Like the others, BMSBs will also congregate on buildings 
			looking for somewhere to overwinter.
 [to top of second 
            column] | 
            
			 
				 
			But unlike boxelder bugs and multicolored Asian lady 
			beetle, these insects are more than a nuisance. According to 
			Johnson, “They will feed on a wide variety of tree fruits, 
			vegetables, agricultural crops, and ornamentals and can cause a 
			significant amount of damage.” 
			 
			They have the typical ‘shield’ shape of stink bugs. 
			And, as their name implies, BSMBs are brown and marmorated 
			(mottled). There are a few characteristics that can be used to 
			differentiate them from our native stink bugs: the antenna are 
			striped with white bands, they have smooth “shoulders,” and they 
			have black and white triangular patterns on their abdomens. Several 
			other insects are commonly confused with BMSBs. Johnson recommends 
			contacting your local Extension office if you are unsure. 
 For all of these insects, the best management strategy for keeping 
			them out of your home is exclusion. Johnson says, “Make sure windows 
			and doors fit tight and window screens are free from holes. Seal any 
			openings, cracks, and crevices around the foundation, pipes, wires, 
			and chimneys. Finally, make sure siding, eaves, and soffits are in 
			good condition.”
 
 Insecticides can be applied to the perimeter of buildings, but since 
			these insects are rather mobile, it can be difficult to get good 
			control of them. Once they enter your home, they can be vacuumed up 
			and placed in soapy water and disposed of. Using insecticides to 
			control these insects indoors is generally not recommended.
 
			[Ken Johnson, Horticulutre Educator, 
			University of Illinois] |