47 



entire leaf, leaviug nothing but the larger veins or ribs. When at 

 rest they usually hold fast to the edge of the leaf by the three pairs 

 of thoracic legs, coiling the body in a spiral form on the underside 

 of the leaf. 



There are usually two broods of these worms produced in one 

 season, and although these broods sometimes overlap each other, so 

 that specimens may be found at almost any time from the first of 

 June to the first of August, yet there is usually a brief interval in 

 the latter part of June when very few of the worms are to be found. 

 When fully grown they crawl beneath the leaves and other litter, 

 and each one spins a tough, brown elliptical cocoon. Some of the 

 worms of the first brood assume the chrysalis form soon after spin- 

 ning their cocoons, and are changed to flies in from two to four 

 weeks later. The other worms of this brood, and all of those of 

 the second brood, pass the winter in the larva or pupa state, and 

 are changed to flies in the month of April or May of the following 

 year. 



The female fly is of a light yellow coloy, marked on the head and 

 thorax with black ; her wings are transparent and expand about 

 five-eighths of an inch. 



The male fly differs so much from the female in color and general 

 appearance that it might easily be supposed that he belonged to a 

 different species. His body is black and the abdomen is usually 

 ringed with pale yellow ; the tip of the abdomen is also of this color. 



The first fly of this species which I captured the present season 

 was a male, and w-as taken May the 9th ; about the 23d of this 

 month three females were captured, one while in the very act of 

 depositing her eggs upon a currant leaf. The eggs are placed on 

 the underside of the leaf, on the larger veins, the female fly first 

 rasping off the skin, or epidermis, from the veins before attaching 

 her eggs to them. The eggs hatch out in a few days, and the worms 

 attain their full size by about the middle of June, when they desert 

 the bushes and spin their cocoons beneath the leaves and other 

 litter that lays upon the ground. By the twentieth of June scarcely 

 one of these worms was to be found where, but a short time before, 

 the bushes literally swarmed with them. In the course of a week 

 or two another brood of worms appeared, and these reached their 

 full growth toward the end of July, when they deserted the bushes 

 and spun their cocoons as the first brood had done. This was the 

 last brood that appeared, although Prof. Eiley says* that a third 

 brood is sometimes produced. 



On the 16th of June of the present year (1881), I enclosed about 

 a dozen of these currant worms in one of my breeding cages ; two 

 days later some of them began spinning their cocoons, and by the 

 twentieth of this month all had inclosed themselves in their cocoons. 

 The first fly issued July 4 ; another issued a few days later, and a 

 third put in its appearance on the tw^entieth of this month. This 

 was the last fly that issued, and on the r2th of August I opened 

 one of the cocoons and found it to contain a living larva. Here 

 then was an individual of the first brood still in the larva state, 

 wdiile those of the second brood had deserted the bushes and spun 

 their cocoons at least two weeks previously. It would be interesting 



* Ninth Annual Report, etc., page 11. 



