INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



203 



that spraying is impracticable. The bugs may be trapped by placing 

 in the garden, hoards, pieces of bark or similar material under which 

 they may find shelter. They may then he collected in the early morn- 

 ings and destroyed. Young plants may be covered to afford protection 

 until they are able to resist the attacks. Repellents, such as gypsum 

 saturated with kerosene or turpentine, scattered on the land arc said 

 to help to drive them away. Clean culture is also suggested, care 

 being taken to burn all vines and rubbish in the fall. Thoroughly 

 fertilizing and watering the hind may so stimulate plant growth ;is to 

 make the attacks of the bug of little avail. 



Fig. 170. — Adults of the squash bug, Anasa tristis DeGeer. Enlarged one 

 and one fourth times. (Original) 



Natural Enemies. 117 — In the Eastern States the egg parasites. Jlud- 

 ronotus anasce Ashm. and Omncyrtus anasa Aslnn. prey upon the 

 squash hug. A tachinid fly, Trichopoda pennipes Fab. attacks the 

 nymphs and adults, which are also subject to a bacterial disease, 

 Bacillus entomotoxicon Dugger. 



THE CACTUS-JOINT BUG 



Chelinidea tabulata Burmeister 1 " 



I Fig. 180) 



Description. — The color of the adult bugs varies from yellowish to 

 reddish-brown, dark olive-green or nearly black, hut the usual color is 

 dusky -yellow with the antennae, parts of the head, front and posterior 

 margins of the prothorax, membrane of the wings and the leys dark 

 brown or nearly black. The shape and general appearance are shown 

 in Pig. 180. The length averages aboul I inch. The eggs are elliptical, 

 dark brown, mottled with whitish exudation, with finely punctured 



n'Cir. Xo. ::'.'. Bur. Ent, U. S. Dept. Agric, p. 4. 1908. 



""-Mi-. E. P. Van Duzee considers this species as probably a dark form of Chelinidea 

 vittigera Uhler, which has been reported as attacking the Opuntia in the southern 

 part of the State. Bui. No, 113, Bur. Ent. U. S. Dept. Agric, pp. 15-19, 1912, 



