Mr. F. Walker's Descriptions 0/ Aphides. 341 



folded, and as yet milk-white, and slightly opake, all the veins 

 have the same thickness, and then also the third vein is more 

 clearly defined close to its source, and the widening of the main 

 vein into the brand is more distinct. The wing-brand sometimes 

 forms a cm-ve along its hind-border, the angle being obsolete. 



The oviparous wingless female. The body is rose colour, and 

 gradually increases in breadth from the head to near the tip of 

 the abdomen, and as is usual in this generation is somewhat at- 

 tenuated behind the nectaries : the feelers are shorter than the 

 body : the legs are shorter than those of the winged female ; the 

 hind-shanks are hardly or not at all dilated, and this variation 

 also occurs in A. Quercus : the body of the latter species is more 

 lengthened towards the tip than that of A. Quercea, and the 

 feelers of the former are shorter than the body. 



Length of the body 1 line ; of the wings 2^ lines. 



14. Aphis Alni, Fabr. 



Aphis Alni, Fabr. Eut. Syst. iv. 215. 26; Syst. Rhyn. 298. 

 26 ; Gmelin, Syst. Nat. i. 2206; DeGecr, Ins. iii. 47. 4. t. 3. f. 15- 

 17; Latr. Gen. iii. 173; Kirby and Spence, Intr. Ent. iii. 76; 

 St. Farg. et Serv. Enc. Meth. Hist. Nat. x. 248 ; Kalt. Mon. 

 Pflan. i. 137. 105 ; Ratz. Forst. Ins. iii. 219. 



A.7naculata,Yon. Heyden, Mus. Senk. ii.297; A. punctipennis? , 

 Zetterstedt. 



This Aphis feeds on the alder {Alnus glutinosa) from the be- 

 ginning of May till the end of November. It is a scattered 

 species. 



The viviparous wingless female. When young it is linear and 

 white, but when full-grown it is very pale whitish green, half- 

 transparent, nearly oval, hairy, and rather flat : there are three 

 large transverse vivid green spots on the back ; the second one 

 reaches nearly across, and is almost or quite divided in the mid- 

 dle : the front is slightly convex : the feelers are shorter than the 

 body ; the fourth joint is much shorter than tlie third ; the fifth 

 is shorter than the fourth ; the sixth is a little more than half 

 the length of the fifth ; the seventh is shorter than the sixth : 

 the tips of the joints of the feelers, the eyes, the tip of the mouth, 

 and tlie feet are black : the nectaries are extremely short. In 

 May. 



1st variety. The feelers are a little longer than the body. 



2nd variety. A black spot near the tip of each hind-thigh. 



The young ones in the body are twenty and upwards in 

 number. 



The viviparous winged female. This unfolds its wings in the 

 beginning of May : it is yellow : the head and the chest are chiefly 

 dark green ; their sutures and borders arc pale green : the abdo- 



