INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



1!)!) 



HETEROPTERA (Suborder) 



TRUE BUGS 



The members of this suborder comprise those insects commonly known 

 as hugs. Most of them have wings which are thickened al the base and 

 folded so as to make a distinct "X" upon the back. The young appear 

 much like the adults, but lade wings, developed sexual organs and are 

 very much smaller. 



Though most of them are destructive to vegetation, many are carniv- 

 orous and wage continual warfare against injurious insects and other 

 animals. 



In habits there is also a great variance, both aquatic and land forms 

 heing represented. 



Many are known as "stink hugs." because of the peculiar and offen- 

 sive odor which is secreted for protective purposes. 



PENTATOMIM (Family) 



SHIELD BUGS 



The members of this family are usually of medium size, somewhat 

 shield-shaped, Hat and because they emit a very pungent odor are also 

 called ".stink bugs." The antennas are live-jointed, which gives rise to 

 the family name. The tibia? have very few or no spines. In habits they 

 vary greatly, some are plant feeders and therefore injurious, while 

 others are carnivorous and may he classed as beneficial. 



THE RED-SHOULDERED PLANT-BUG 



Thyanta custator (Fabricius) 



(Fig. 175) 



Description. — The full-grown bugs vary from yellowish-green to 



bright green or brownish-green, with distinct red shoulders and often 

 with a broad red band across the prothorax between the shoulders. The 



tip of the scutellum and the margins 

 of the fronl wings are also sometimes 

 lined with red. The membranous 

 parts of the wings are colorless, and 

 when folded form a light area on the 

 posterior dorsum. The average length 

 is about | inch and the width across 

 the base of the prothorax | inch. 

 When disturbed they emit a very 

 offensive odor. 



Life History. — The adults hibernate 



in sheltered places and appear on the 



plants in scattering numbers in the 



spring, when egg-laying begins. The 



and mature within a month. There 



Fig. 175. — The red-shouldered plant 

 bug, Thyanta <nsttit*>r (Fab.). Adult; 

 enlarged three times. (Original) 



young hatch early in summer 



appears to lie hul one uneven brood a year. 



Nature of Work. — These bugs pierce and suck the .juices of the host 

 plants, and, where large numbers congregate, they may cause a decided 



