No. 115.] 113 



where they had been feeding until the matured grain could give 

 them no further sustenance, they were now seeking or waiting the 

 fall-sown wheat or rye upon which they could deposit eggs, and 

 thereby provide for the new life-cycle of the coming year, the 

 present cycle being upon the point of completion. 



It is proper to state that the canse and purpose of the flights, as 

 outlined above, is simply conjectural, based on our knowledge of 

 other species, for the full life-history of the grain aphis is still 

 unknown, and in several particulars it is proving quite enigmatical 

 to us. No description of the male appears in any writings to 

 which I have access, and in 1862 Dr. Fitch wrote as follows of it : 



I have watched the grain aphis this year round so closely that 

 I am perfectly assured that no eggs were laid and no males were 

 produced. When and under what circumstances males occur, if 

 they ever do occur, is yet remaining to be discovered. At present 

 it seems as if these insects might go on forever producing young, 

 without any intercourse of the sexes. {^Transactions N. Y. St 

 Agricul. Soc, xxii, 1862, p. 36.) 



A year earlier (in 1861, in Sixth Kept. Ins. N. Y.) Dr. Fitch 

 had stated that the eggs remain tlirough the winter to be hatched 

 by the warmth of the following spring. Subsequent observations 

 failed to sustain this conjecture, as it was found that some of the 

 insects hibernate under the ground to lay their eggs the following 

 spring; or, that the eggs laid in the autumn hatch soon after they 

 are deposited and that the annual round, to be continued through 

 most of the ensuing twelve months, is then commenced. This 

 appears from observations of Dr. Thomas, formerly State Entomolo- 

 gist, of Illinois, who, in 1878, published the following as additional 

 contributions toward the life-history of the species : 



When the winter wheat appears above the ground in the fall it 

 passes [to it] from its hiding place at that time, wherever that may 

 be. * * * Here they work upon the leaves and stalks singly 

 while the weatlier 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 the snow was on the ground ; and, what somewhat 

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

 apterous females bearing well-formed larvae. I am therefore led 



[Assembly, No. 115.] 8 



