214 



INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



and genera] appearance, but is much smaller and has proportionately 



shorter antenna', which are only about two thirds the length of the 



body. The length of the 



females is aboul -\. inch Long, 



the males being somewhat 



smaller. 



Life History. — The life his- 

 tory appears to be practically 

 the same as that of the larger 

 species (Irbisia brachycerus 

 Uhler). 



Nature of Work. — The 

 work consists in making yel- 

 low spots on the foliage, 

 which may later turn entirely 

 yellow and die. Fig. 189 

 shows this work very well. 



Distribution.— This species 

 occurs in the State north of 

 the Tehachapi and was espe- 

 cially abundant in the Santa 

 Clara Valley in May. 1914. 



Food Plants. — Grass and 

 weeds are oatiye hosts, but 

 barley, oats and wheat are 

 also at times severely injured, 

 as was observed in 1914 by 

 Leroy Childs. lie also noted 

 the following food plants: 

 Amsinckia intermedia, man 

 root, malva, mustard, thistle 

 and sow-thistle. 



Control.- Control measures are the same as for the black plant-bug 

 and the tarnished plant-bug. 



Fig. 189. — The lesser black plant-bug', Irbisia 

 st ricans Stal. Adults and work on oats. Nat- 

 ural size. Specimens taken at Stanford Uni- 

 versity by Leroy Childs. (Original) 



