

CURRANT PLANT LOUSE 149 



Control. The nymphs may be killed by spraying with kerosene 

 emulsion. But the tobacco extracts are particularly recommended. 

 It is to be noted that the adults are not susceptible to treatment. 

 Both nymphs and adults will drop when disturbed. 



The Yellow-bear Caterpillar is injurious to berries, currants 

 and gooseberries as well as to many other plants. See the discus- 

 sion on page 160, under Grape Insects. 



The Currant Plant-louse. This aphid (Myzus ribis Linn.) 

 sucks the juices from the leaves of the currant, causing them 



r 



.JBBHHI 



FIG. 168. Currant leaves infested with lire. (Lugger.) 



to curl and form incomplete galls, inside of which the lice 

 stay. Their presence on the under side of the leaf is indicated 

 by the striking red color on the upper surface (Fig. 168). 

 In midsummer they migrate to some other plants for food 

 or become greatly reduced in numbers by parasites and pre- 

 daceous insects. 



Description. The winter is passed in the egg stage, like many 

 other aphids, these eggs hatching when the foliage appears. The 

 wingless females are one-twelfth of an inch long; green or yellowish 

 green, mottled with darker shades. The eyes are bright red. The 

 winged females are slightly larger than the others. 



