This pest seems to be rather erratic in its outbreaks in both Europe 

 and America. To the .agriculturist it suddenl}' appears in immense 

 swarms on the grain in the fields in spring, ruins the crop over large 

 areas of country, and does not reappear in destructive numbers, perhaps, 

 for many years. The fact is, however, that it can be found in the grain 

 fields during any year, throughout the region it infests, although it may 

 not be sufficiently abundant to work serious injury. The extreme 

 rapidity with which this insect multiplies, unless restrained by natural 

 checks, gives color to the farmer's belief in its sudden appearance, for 

 within a few weeks, from numbers too few to ))e readily noticeable, it 

 will develop myriads that swarm over the green plants, turning whole 

 fields of thrifty grain to brown, dwarfed plants that produce no heads, 

 or else, reaching a height of not more than 6 to 8 inches, iiave heads 

 that are foreshortened and nearly devoid of kernels. Thus it is that 

 within the short space of less tlian twenty j'ears this aphis has come to 

 be one of the worst i)ests of its kind in the grain fields of the south- 

 central pDrtion of our country. 



SEASOXAI. HISTOKY. 



The life cycle of tliis insect does not appear to differ from that which 

 is usual among aphides. The single generation of males and sexual or 

 egg-laying females appears, as far north, at least, as latitude 40° 27', in 

 October, but possibl}^ earlier to the south. The egg-laying female is 

 wingless and may be easily distinguished by her position on the plant, 

 the body being held almost at right angles instead of parallel to the 

 leaf. She may be further identified l)\^ the eggs, which show through 

 the skin, their outlines appearing like lateral oblique lighter lines on the 

 abdomen. 



The eggs, which are glossy green immediately after deposition, but 

 later turn jet black, are laid among the grain plants in the fields. 

 Possibly' some are placed elsewhere, but if so the writer has failed to 

 fin/:! them. While these aphides overwinter in the egg state, they also 

 pass the winter as viviparovis females in the fields as far north as lati- 

 tude 40° 11' , where the writer has found them reproducing by the first 

 of April. The writer has kept them I)reeding within doors where the 

 temperature during the night frequently fell below the freezing point 

 and ink was frozen in the inkstand on the desk. In this way they were 

 reared throughout the entire winter of 1889-90 at Lafayette, Ind. In 

 the same locality, in 1884, they were breeding in the fields until after 

 the middle of December. There is no doubt whatever that in the South, 

 and even as far north as St. Louis and Cincinnati during mild winters, 

 the species breeds in this way during the entire winter, though the eggs 

 deposited in fall probal)ly do not hat(^ii under such low temperatures, 

 biit j-euinin unhatclietl until spring. 



