Insects, etc., Iiijurious to Currants. 



219 



differ much from the wingless female or larva. The winged vivi- 

 parous female, which arises from the pupa, is yellowish-green with 

 black head and antenna^ ; the thorax is black with a yellow band 

 in front ; the abdomen is a bright yellowish-green, with dark spots 

 and patches on the back and sides ; yellow honey-tubes, swollen 

 towards the apex ; legs ochreous, with the joints and the feet black. 

 These winged females fly from bush to bush. In the autumn or 

 late summer males and egg-laying females are formed; the egg- 

 laying female, after being fertilised, deposits a few brown elongated 

 eggs on the last year's growth of a twig just under the broken rind or 

 upon it. Here the eggs 

 remain all the winter. 

 This aphis, besides feed- 

 ing on the red, black, and 

 white currant, also attacks 

 the gooseberry, and it has 

 been found in the Guelder 

 Eose, the Nipple Wort, 

 and the Sow Thistle. 

 Walker many years ago 

 suggested that this species 

 flew to the lettuce as its 

 second host plant, and 

 from what I have ob- 

 served I am inclined to 

 think this is correct, for 

 I can detect no difference 

 in the aphides found on 

 lettuce in the late sum- 

 mer, and certainly this 

 species leaves the currants in great numbers in late summer. 



(II.) Myzus ribis, Linn. — This plant louse can easily be dis- 

 tinguished from the former, with a lens, by its olive, not black, head, 

 and its black honey-tubes and irregularly black ornamented abdomen 

 in the winged female. It occurs from April to August, especially 

 in the black currant and gooseberry, but also on the red currant; 

 it is said to cause blisters similar to (I.). It often causes the leaves 

 at the apex of the shoots to curl and twist up. I have never been 

 able to find any blisters formed by it. 



The wingless female, which appears in the spring, is shiny 

 yellowish-green, with dark green mottlings, elongated oval in form, 

 and with curious hairs in front; the honey-tubes and legs are 



1.1. I', n. liint'iuL 

 FIfi. 16S.— CAST SKIN OR EXUVIUM OF AN APHIS. 



(Greatly enlargeiL) 



