304 Mr. F. Walker's Descriptions of Aphides. 



65. Aphis AveUanoi, Schrank. 



Aphis AvellancB, Schrank, Faun. Boic. 112. 1207; Kalt. Mon. 

 Pflan. 143. 116. 



This species clusters on the stalks and shoots of Corylus Avel- 

 lana, whereas A. CoTyli is scattered on the leaves of that tree. 



The vivijjarous wingless female. The body is oval, convex, hairy, 

 pale green, and varies in breadth : the front is bristly, and has a 

 protuberance in the middle, and one more slight at the inner base 

 of each feeler : the feelers are pale yellow and very much longer 

 than the body ; the tips of the joints are brown ; the first and the 

 second joints are bristly, and the third is also so to a less degree ; 

 the fourth joint is a little shorter than the third ; the fifth is as 

 long as or longer than the fourth ; the sixth is less than half the 

 length of the fifth ; the seventh is more than four times the length 

 of the sixth : the mouth reaches the hind hips, or very near thereto, 

 and even much beyond them in the young insects : the nectaries 

 are green, and full one-fourth of the length of the body ; they 

 are slightly tapering from the base to the tips : the tip of the 

 abdomen does not form a tube : the legs are pale yellow, very 

 long and hairy ; the shanks are very slightly curved ; the fore- 

 legs are but little shorter than the hind-legs ; the feet and the 

 tips of the shanks are brown : the young ones in the body some- 

 times amount to twenty or upwards. 



1st var. The feelers are a little shorter than the body ; the fifth 

 joint is longer than the fourth ; the sixth is full half the length 

 of the fifth ; the seventh is about one-third of the length of the 

 sixth. 



2nd var. The seventh joint of the feelers is about five times 

 the length of the sixth. 



3rd var. The body is rose-colour. 



4th var. The body is lilac-colour. 



The viviparous winged female. While a pupa it resembles the 

 wingless Aphis in colour : the rudimentary wings are pale 

 green, and when they are unfolded, the head and the disc of the 

 chest have a darker colour : the wings are colourless, and much 

 longer than the body ; the second vein diverges rather more from 

 the first than it does from the third ; the forks of the latter are 

 inconstant in length, and sometimes the situation of their source 

 varies in the opposite wings of the same insect ; the fourth vein 

 is but slightly curved, and the angle of the brand whence it 

 springs is extremely slight. 



Length of the body 1 line ; of the wings 3 lines. 



[To be continued.] 



