INSECTS INJURIOUS TO CURRANT AND GOOSEBERRY 429 



Control. Hellebore is not as effective as against the saw-fly 

 larvae and as the larvae usually appear before the fruit is setting, 

 they may be better controlled by spraying with arsenicals. When 

 the caterpillars are disturbed they drop from the foliage, letting 

 themselves down by a silken thread and remaining suspended in 



FIG. 360. The currant span-worm (Cymatomorpha riberia Fitch): 1, 2, larvae, 

 3, pupa; a, egg; 6, eggs on twig; c, moth a, much enlarged, others natural 

 size. (After Saunders.) 



mid-air until danger is over, when they reascend the thread. 

 This habit may be utilized for their destruction by jarring the 

 bush so that they will drop, and then passing a forked stick around 

 it so that all the threads may be caught and the caterpillars may 

 be drawn out in groups and crushed with the foot. 



The Currant-fly * 



Currants and gooseberries sometimes turn red and drop pre- 

 maturely, due to the injury by small maggots which may be found 

 within them. The insect has been troublesome in Maine and is 

 sometimes a serious pest in Colorado. It is a native insect and is 

 probably generally distributed throughout the northern United 

 States and southern Canada. The adult fly is about the size of 



* Epochra canadensis Loew. Family Trypetida. See F. L. Harvey, 

 Bulletin 35, Maine Agr. Exp. Sta. 



