INSECTS INJURIOUS TO THE APPLE AND PEAR 



535 



The European Grain-aphis * 



This species is found on the apple, pear, quince and plum in the 

 spring and fall and on the small grains and various grasses during 

 the summer. Until recently it has been the more common form 

 on apple in the East, but is not now so numerous as the apple- 

 aphis. It is an old European species and was evidently imported 

 to this country at an early date, as it is widely distributed through 

 out the United States. The wingless females are distinctly 

 smaller than the previous species, and are of a light green color, 

 marked with transverse diamond-shaped bands of darker green, 



FIG. 465. The European grain-aphis (Aphis avence Fab.): wingless viviparous 

 female, and egg-laying or oviparous female greatly enlarged. 



across the abdominal segments. The honey-tubes are shorter, 

 distinctly enlarged at the middle and flared at the tip, which 



*Aphis avenoB Fab. Family Aphididce. See Th. Pergande, Bulletin 44, 

 n. s., Div. Ent., U. S. Dept. Agr., p. 5 and authors cited above. The author 

 described this species as Aphis fitchii in 1902, and although there seems to 

 be no question that it feeds on grains and grasses during the summer, there 

 are several reasons for believing that there are either two species or that the 

 life history has not been sufficiently observed. Thus in some sections it is 

 exceedingly common on grain but rare on apple, and in others just the opposite 

 condition is found. Matheson, I.e., uses for this insect the name Aphis avence 

 Fab., but Baker and Turner, Journal Agr. Research, Vol. XVIII, No. 6, call 

 the species on apple the apple-grain aphis and ascribe to it the name Rho- 

 palosiphum prunifolice Fitch. They maintain that the name Aphis avence is 

 a synonym for R. padi L. It is to be hoped that the systematists in this 

 group will soon come to an agreement for the sake of uniformity. It should 

 be mentioned that the latter authorities, I.e., under Rosy Apple-aphis, consider 

 that species as Aphis malifolice Fitch rather than as A. sorbi Kaltenbach. 



