PACKARD J THE GRAIN-APHIS. 711 



must be cut oft", tbe virgin females produce winged individuals of both 

 sexes, which after pairing die, after depositing their eggs for the spring- 

 brood. 



Our species is oblong-oval shaped, narrowing toward the head, while 

 the abdomen behind is swelled out and rather blunt at the end, with a 

 rather long ovipositor in tbe female. Its color is green, covered often 

 with a reddish-brown bloom. The ends of the antennae, the end of the 

 shanks and thighs and the feet, are black. In the young, these parts are 

 only smoky or dusky. Length of those with wings about one-tenth of 

 an inch. 



Dr. Fitch gives in the Boston Courier, interesting observations on 

 this aphis. Of its variation in color he says : "One of the most remark- 

 able circumstances relating to these insects is the change in their color 

 which now began to take place. While they were scattered about upon 

 the leaves and stalks of the grain, they were of a bright grass-green 

 color. Now orange-yellow or deep liesh-red individuals began to appear 

 among them. This color is so wholly different from green, that these 

 orange ones might be suspected to be a different species. But green 

 females placed in vials were found nest day to have young with them 

 of both colors ; some being green, others orange. And a iew days later 

 other green females were found to have orange young only, no green 

 ones being born any longer. It is probably the change in the quality' of 

 its food which causes the insect to change thus in its color, the juices 

 which the plant elaborates for the growth of its flowers and seeds being 

 much more highly refined, nutritious, and dainty than those which cir- 

 culate in the stalks and leaves, where the insect first feeds. And it is 

 truly curious and wonderful that this green-colored insect, on coming to 

 feed on the juices which grow the flowers, begins thereupon to give birth 

 to young having a gray orange color similar to that of the flowers." 



Dr. Fitch noticed several years ago in wheat-fields a green plant-louse, 

 though it was not common. 



In East Hampden, Mass., "a plant-louse of a pale brick-red color was 

 extremely numerous'' in 18G0 ; so, also, a "red insect" on the oats in New 

 York was sent him. We thus know the insect we are to speak of was 

 overrunning the fields in some places last summer. 



"Early in ]\Iay last, when rye and winter- wheat were but a few inches 

 out of the ground, I met with this insect more numerous than any other 

 in every part of every grain-field in my neighborhood. Toward the 

 close of that month specimens having wings began to occur. By in- 

 closing them singly in vials, I found that the winged female usually gave 

 birth to four young lice in twenty -four hours, while those without wings 

 produced eight within the same time." 



The grain-aphis became noticed the 18th July in New Jersey, then in 

 the New England States. Probably very few farms in ]\Iaine escaped 

 its presence. About the first of August I noticed them on a farm about 

 thirty miles above Mattawamkeag, on the Penobscot Iliver. Also on 

 farms on the lakes that form the headwateus of the Penobscot and Al- 

 leguash Rivers, and on the xUleguash and Saint John. I also heard of 

 its occurrence in great numbers on the Saint John in New Brunswick. 

 Like the army-worm, while abundant on some fields, others were entirely 

 free from its attacks. 



The injury this aphis does is to lessen the weight of the grain, which 

 of course is a matter of great consequence. The constant draining of 

 the sap that flows into the ear causes it to be very light, if not withered 

 and worthless. 



