INJURIOUS AND BENEFICIAL TNSECTS OF CALIFORNIA. 



319 



the color of the adults as they mature. The body segments are pro- 

 vided with sharp spines, which project backwards and by which the 

 insects are able to wriggle to the surface when ready to emerge as 

 adults. 



Life History.— The eggs are deposited as deeply in the soil as the 

 length of the female's abdomen will permit and are laid throughout the 

 spring and summer. They 

 soon hatch and the maggots, 

 or "leather jackets," feed 

 upon the roots of plants. They 

 usually live in rather moist or 

 even wet places, and remain 

 in the larval stage during the 

 winter and pupate in the 

 spring. There is probably 

 but one brood a year. 



Distribution.— The insect is 

 common in the central and 

 northern parts of the State. 



Food Plants. — The larvae 

 feed entirely upon the roots of 

 plants, a variety being at- 

 tacked. Serious damage has 

 been reported in alfalfa and clover fields. They are most important as 

 a pest in pasture lands, where they may destroy the grass over large 

 areas. According to Professor R. W. Doane, in some regions, in par- 

 ticularly favorable years, the shortage of grass due to this insect has 

 been so great that many of the cattle on the ranges have died of 

 starvation. 



Control.— The greatest amount, of damage is usually done in fields 

 which have long been seeded to alfalfa or clover, where the breeding 

 has not been disturbed. Plowing and thorough cultivation will destroy 

 most of the larva 3 , which are either crushed or die for lack of sufficient 

 moisture. The females, being wingless, are unable to migrate suffi- 

 ciently to cause serious damage in one year. A cultivated crop once in 

 two or three years, as a rotation with clover or alfalfa, is recommended 

 when the destructiveness of the pest warrants strict remedial measures. 

 On the ranges there is no remedy that would justify its cost. 



Natural Enemies.— E. K. Carnes and E. J. Newcomer 232 report a 

 tachina fly as parasite upon the larvae. 



Fig. 313. — The alfalfa crane-fly. Tipula sim- 

 plex Doane. Winged male and wingless female. 

 Natural size. (After Carnes and Newcomer, 

 Mo. Bui. Cal. Hort. Com.) 



THE CACTUS-FRUIT GALL-FLY 



Asphondylia opuntice Felt (Family Cecidomyidae) 

 (Fig. 314) 



Description. — The flies resemble mosquitoes somewhat because of 

 their small size, long legs and slender shape. The bodies are gray and 

 almost | inch long. Fig. 314 shows the general characters very well. 

 The larva? are nearly cylindrical, white and fk inch long. The puparia 



2 "-Mo. Bui. Cal. Hort. Com., I, p. 279, 1912. 



