INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



205 



summer the mature bugs may become very abundant and congregate 

 in large numbers. They often hang like bees upon tree trunks and in 

 various places, causing much worry and alarm to those not familiar 

 with their habits. During the winter they occasionally enter houses 

 and are quite annoying. 119 



181. — The box-elder plant-bug. Lcptocoris trivitiatus (Say). 

 Adults slightly enlarged. (Original) 



Nature of Work.— Foliage attacked by the box-elder plant-bug 

 becomes yellowish and soon drops from the trees. Fruits from which 

 the juice has been extracted dry up and either fall to the ground or 

 fail to mature. The presence of the bug will always aid in discovering 

 the source of such injuries. 



Food Plants. — The normal food of this bug appears to be the foliage 

 of the box-elder (Negundo aceroides), but it also feeds upon various 

 other plants. During the summer the bug sometimes attacks fruit, 

 often entailing much loss by sucking out the juices. Apples, grapes, 

 peaches and plums have been thus injured. 1 -" Air. Geo. P. Weldon 

 found it feeding upon cherry trees in the Yucaipa Valley, San Bernar- 

 dino County. May, 1914. 



Distribution. — It occurs throughout the entire State and is very 

 common in all of the Western States. 



Control. — Only seldom does this bug become a pest and therefore 

 hardly need receive more than occasional attention. The large numbers 

 of bugs massed upon the tree trunks during sunny days in winter are 

 easily collected and destroyed, thus greatly reducing spring broods. 

 The young bugs are also readily killed with a soap, tobacco or oil emul- 

 sion spray. 



'"Insect Life VI. p. 328, 1894. 

 '-'"Insect Life, IV, p. 273, 1892 



