606 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



the winter, but it may be questioned whether they usually survive 

 the winter on grains or grasses in the North. 



Professor F. M. Webster* has observed this species on wheat in 

 Ohio, and states that in mild winters it remains on the wheat, 

 going down on the stems to just below the surface of the soil or 

 to the upper roots, as we have observed it in Texas. " Here they 

 go on reproducing when the temperature is favorable," he says, 

 " the adults being apterous so far as observed by me, until spring, 

 when they ascend to the foliage, the adults after this being both 

 winged and wingless. On the stems and roots below the surface 

 of the ground they are of a greenish color, tinged with reddish- 

 brown, especially posteriorly, the full-grown individuals often 

 being wholly of a dark brown. It is during autumn that they 

 do their greatest injury to the wheat, by sucking the juices from 

 the young plants, often, if on poor land and if in dry weather, 

 checking their growth and causing the foliage to turn yellow." 

 This species is seldom much in evidence on grains or grasses in 

 midsummer and rarely becomes very injurious to them. On 

 the apple it is abundant on the young foliage and particularly 

 on the flower buds and blossoms, where it is much more common 

 than the other species. It does not, however, curl the foliage 

 nearly as severely as the other species, due to its earlier migra- 

 tion. 



The Clover-aphis f 



This species is more particularly a clover pest, but is mentioned 

 because it oviposits, on apple and pear and may be confused with 

 other species in spring and fall. It has been observed in Colorado 

 and has been injurious to clover in Iowa, but its further distribution 

 is unknown. The wingless female of the first generation varies 

 from a dark green streaked and mottled with red to a deep dark 

 red, with honey-tubes very short and pale yellow throughout. 

 The second generation are light green or yellowish-green and 



* See Bulletin 51, Ohio Agr. Exp. Station, p. 111. 



f Aphis bakeri Cowen. Family Aphididce. See Gillette and Taylor, I.e.; 

 C. P. Gillette, Journal Economic Ent., Vol. I, p. 364. 



