INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



213 



THE BLACK PLANT-BUG 

 Irbisia bracfoycerus Uhler 



(Fig. 1SS) 



Description. — The adults are rather slender, dark metallic bronze 

 or black in color with light brown legs. The antennae are as long or 

 are nearly as long as the body. 

 The females are about % inch 

 long and the males only slightly 

 smaller. 



Life History. — The breeding 

 habits of this species are yet 

 unknown, but the young are 

 evidently reared in the grasses 

 and grainfields, maturing in 

 May and June. At this time 

 they often do great damage to 

 various crops. All nourish- 

 ment is obtained by sucking 

 the juices from the hosts. The 

 winter is passed in the adult 

 stage. 



Nature of Work. — The leaves 

 of grasses and grains attacked 

 by this bug first show numer- 

 ous yellow spots, as shown in 

 Fig. 188. Soon the whole leaves 



-him vpllnw and dip OtTipv F *& ]8N - — Tl "' black plant-bus. Irbisia 



turn yeilOVv ana (lie. Utliei 6rac ft vcem Uhler. Adults and their work 



plants behave in the Same man- on wheat. Slightly enlarged. (Original) 



ner and in many cases the discoloration of the tissues is accompanied 

 by a curling of the leaves. 



Distribution. — The black plant-bug is common throughout the 

 State and has been observed as injurious in a number of localities. 127 



Food Plants. — Grass, various weeds, In [lines and many other plants 

 are native hosts of this insect. It also occasionally attacks such culti- 

 vated plants as barley, cucumber, lettuce, oats, onion, peach, potato, 

 radish, rhubarb and wheat. 



Control.— In grainfields control measures are difficult, as the bug 

 feeds quite near the ground. If the growth is not too large a hopper- 

 dozer might be used with good results, in tr;ick gardens the applica- 

 tion of a repellent, as hellebore or possibly Bordeaux mixture, may 

 give good results. The measures as recommended for the tarnished 

 plant-bug are also applicable for this insect. In all probability, how- 

 ever, the injuries seldom warrant control measures. 



THE LESSER BLACK PLANT-BUG 



Irbisia serial us Stal 

 189) 



Description. — This bug greatly resembles the black plant-bug 



(Irbisia brachycerus Uhler), to which it is closely related, in color 



'"Vosler, E. J., Mo. Bui. Cal. Hort. Com., II, pp. 551-."",:,::, 1913. 



