182 INSECTS IXJURIOUS TO STAPLE CROPS. 



The Destructive Pea-louse or "Green Dolphin" (Xectaro- 

 pli ora p is i Kalt . ) . 



Considerable injury was done to both red and scarlet 

 clover by this pest in the spring of 1900 in Virginia, Dela- 

 ware, and Maryland, and to crimson clover in Delaware in 

 1890. In Europe the " Green Dolphin '' has been known 

 as one of the worst pests of peas, vetches, and clovers for 

 the past century. The aphids leave the clover about May 

 1st in the above States, and feed upon peas during the 

 early summer, practically destroying the crop of late peas 

 in 1899 and 1900. During October and November they 

 return to the clover and pass the winter upon it. 



Many predaceous and parasitic insects prey u2:>on this 

 pest, but it is held in check, especially on clover, chiefly 

 by a fungous disease (Empusa aj^hidis). This disease is 

 prevented by dry weather, and hence the pest is most 

 injurious in dry seasons. 



As yet no remedy for the pest on clover or means for 

 prevention of injury are known.* 



IXJUEIXG THE SEED. 



The Clover-seed Midge {Cecidofuvia legumhiicola Lint.). 



This is also a native of western New York, where its 

 first injuries were recorded in 1878, but since then it has 

 spread to almost every section where clover is grown, and 

 is so serious a pest that it has become quite an art to raise 

 a crop of clover-seed. The parent of all this trouble is a 



*See Bull. XLIX, Del. Agr. Exp. Sta., "The Pea-louse," E. D. 

 Sanderson ; and Circular 43, 2d Ser., Div. Ent., U. S. Dept. Agr., 

 F. H. Chittenden. 



