12 



ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 47 



Fig. 7. — Boxelder bug: adults. Shown here are boxelder bugs on the 

 foundation of a building. The bugs, which are black and red in color, are of 

 no consequence as pests of boxelder trees, but they are nuisances in and on 

 buildings. 



quarters. Following hibernation, the female lays small, red eggs 

 in bark crevices. The red-bodied, black-legged nymphs that 

 hatch from the eggs reach the adult stage through a series of 

 molts. 



Control Measure 7 (end of circular). 



Boxelder Aphid, Periphyllus negundinis (Thos.). — This is a 

 pale green, hairy plant louse that occasionally develops in great 

 numbers. An infestation by this aphid causes some injury to 

 the infested tree and creates a nuisance by covering sidewalks 

 and other objects beneath the tree with honey dew. Black eggs 

 are deposited by the female on branches in the fall. The eggs 

 hatch in the spring, and young aphids congregate on the new 

 buds, from which they withdraw plant juices through their slen- 

 der beaks. With the ability to develop several generations within 

 a few weeks, these aphids can soon become abundant. 



Control Measure 3 (end of circular). 



Eastern Tent Caterpillar, Malacosoma americanum (F.), 

 fig. 8. — Although black cherry, chokecherry, and apple are 

 favorite hosts, ravenous caterpillars of this species in the 



