INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



)!47 



is often so severe as 1<> completely girdle the stems and thus much 

 damage may result. The puparia are formed in the burrows, espe- 

 cially on the roots and liases of the stalks. There are at least two 

 generations each year. 



Nature of Work.— The maggots work just beneath the epidermis 



of the stalks and often completely girdle the stems, thereby killing 

 the tops. The dead and dying' stalks usually indicate the presence of 

 this pest. 



Distribution. — This fly has been reported by Mr. I. -I. Condil at 

 Antioch and Oakley, in Contra Costa County. It is probably partially 

 distributed in the central part of the State. 

 Food Plants. — This pest works only upon asparagus plants. 



Fig. 344. — The asparagus miner, Agromyaa simplex Loew. Adull flies at the left, 

 greatly enlarged. Immature forms at the right as follows: a, larva or maggot; b, 

 thoracic spiracles and c, anal spiracles of the larva ; </. side view and <■. dorsal view 

 of the puparium ; f, section of asparagus stalk, showing injury caused by the maggots 

 and sections removed to show location of the puparia. All except f arc greatly en- 

 larged. (After Chittenden, U. S. Dept. Agric.) 



Control.— The control of the fly is somewhat difficult and consists 

 in the use of trap crops early in the spring, which should be removed, 

 roots and all, and burned in June. Other traps should be allowed to 

 grow up immediately and similarly destroyed in the fall. 



Cutting out all infested stalks as often as they appear is also 

 advisable. 



D. E. Fink 253 recommends the following spray to kill the larva 1 in 

 the infested stalks: 



"Black leaf 40" 1 gallon 



Soap 4 pounds 



Water 500 gallons 



THE WISTARIA STEM GALL-FLY^' 



Agromyza websteri Matlock 



(Fig. 345) 



Description. — The flies are very small, nol exceeding J inch in 

 length. They are black and hairy with rather la rue reddish-brown 

 eyes. The maggots are white, £ inch long and larger at one end. The 



253 Bul. 331, Cornell Univ. Agrcl. Exp. Sta., p. 410, 1913. 



254 Regarding the wistaria stem gall-fly, Prof. J. M. Aldrich makes the following 

 comment: "This species is made distinct by Malloch in his paper on the family under 

 the name Agromysa websteri Malloch. It is closely allied to A. schineri and, as hut 

 little material is available, I am not vet quite satisfied that they arc not the same. 

 The undoubted A. schineri (Giraud) makes similar galls, but on poplar. 1 had it 

 from Colorado last year." 



