STATE HORTICULTURAL SOCIETY. 167 



Here they work upon the leaves and stalks singly, while the weather 

 is not too cold, but when winter appears they move down toward the 

 ground, some of them, at least, entering the soil and feeding upon the sap 

 of the roots. At any rate, I find the apterous ones at this time working 

 upon the roots, but at the same time I find a winged individual above 

 ground. I have also observed them heretofore at the root of the wheat, 

 late in the winter, while snow was on the ground ; and, what somewhat 

 surprised me, I found them busy at work under the snow, and the apter- 

 ous females bearing well-formed larvre. I am, therefore, led to believe 

 that in this latitude the species passes the winter in other than the egg 

 state. This will also, probably, be found true wherever winter wheat is 

 grown. 



32. Aphis maidis, Fitch. The Maize or Corn Plant-louse. 



This species, which appears to be different from the one infesting the 

 maize in Europe, was formerly supposed to confine its attacks to the stem or 

 peduncle which bears the ear, the most vital point, so far as yield is con- 

 cerned, of the entire plant ; but Mr. Walsh has presented reasons for believ- 

 ing it also attacks the roots, as stated below. When once established, they 

 usually remain until the corn ripens or is cut down. 



The larvae are either green or yellow ; the latter being those which 

 ultimately acquire wings; before changing into pupa^, they usually acquire 

 a pale reddish color, and are dusted over with white powder. 



The wingless females are dull, blackish, tinged with green, and 

 sprinkled with fine whitish powder; head, and generally two bands on the 

 thorax, black ; the abdomen is usually marked with black spots along the 

 sides ; honey-tubes rather short ; autennse, black, and not more than half 

 as long as the body. Wing females, similar ; length of the body, six 

 hundredths of an inch; general color, black; the abdomen, dark green- 

 ish, with black dots along each side and three black bands at the tip. 



It is somewhat strange that maize should have a different aphis in 

 Europe from that which infests it in America. 



Mr. Walsh found a species of aphis infesting the roots of corn, which 

 he is inclined to believe is identical with the one now under consideration. 

 The general color, both of the pupa and perfect insect, is pale green ; the 

 female pupa usually has three short, transverse dark lines on the thorax, 

 and three similar ones on the abdomen. It is figured in the fifth volume 

 of the Transactions of the Illinois State Agricultural Society. If the 

 figure (No. I., page 149) of the winged individual is correct, the antennic 

 are unusually short, scarcely reaching the tip of the thorax ; the honey 

 tubes are also rather short ; the first discoidal vein is farther from the 

 second than the second is from the first, and the stigma is prominent and 

 pointed at each end. He states that the pupa is dusted over with a whitish 

 bloom like that of a plum, and with dusky markings. 



He found these quite abundant on the roots of corn in June, and 

 was led to believe from his observations that it is their normal habit to 

 reside on this part of the plant, being driven to the stem later in the sea- 

 son in search of food, as the root becomes hardened. 



