1862 



THE ILLINOIS FARMER. 



365 



Discussions at the N. Y. State Fair. 



FIRST EVENING. 



Insects — The Grain Aphis, Wheat Midge, ^c. 

 (From the Rural New Yorker.) 



Dr. Asa Fitch, Entomologist to the State Agri- 

 cultural Society, opeced the discussion hy read- 

 ing the following Essay on the Grainr^phis : 



3Ir. Chairman and Gentlemen :—\ am request- 

 ed to preface the discussion, this evening, by 

 presenting to the audience some account of the 

 Grain Aphis — an insect new to us in America, 

 and which, during the past and present year, 

 has been more prominent in the public regard 

 than any other insect. 



In the grain tields of Europe this grain aphis 

 has existed from time immemorial. It was sci- 

 entitically named and described eighty-one years 

 ago, by the distinguished German entomolsgist, 

 Fabricius, who met with it in fields of oats, and 

 therefore named it the Aphis Averaj, or the oat 

 aphis, he being unaware that it occurred equally 

 common upon other kinds of grain also. 



But our European accounts of it are quite mea- 

 ger and imperfect. About all that we gather 

 from them is, that it is an insect which shows it- 

 self upon the grain about the time of harvest, 

 and that in some instances it has been known to 

 be so multiplied, in particular places, as to liter- 

 ally swarm upon and cover the heads of the grain 

 in many of the fields. 



These few general facts is all the information 

 which the world has hitherto bad of this insect. 

 What becomes of it during the remainder of the 

 ye.ar, where, and in what condition it lurks after 

 harvest time, and until harvest time again ap- 

 proaches, had never been investigated. It was 

 remaining for us in this country to trace out its 

 abiding place and its habits during the autumn, 

 winter and spring, and thus complete its history 

 the year round, as we have been able to do with- 

 in the past eighteen months — under the instruc- 

 tions of this Society, and under the auspices of 

 the State of New York. 



In this country, this grain aphis had never 

 been observed, and it was not known that we 

 had such an insect here, until last year, when it 

 suddenly appeared in excessive numbers over all 

 the New England States, and the State of New 

 York, except here in its western section, and also 

 in the adjoining districts of Canada and of Penn- 

 pylvania. Throughout all this vast extent of 

 country every grain field was invaded by it; 

 many of these fields were thronged and a portion 

 of them were litterally covered and smothered 

 and covered by this insect. 



This year it moved westward, making its ap- 

 pearance in the same manner all over Western 

 New York, Canada West, Northern Ohio, and at 

 least a portion of Michigan, as I judge, from the 

 numerous letters which have been sent me with 

 grain-heads containing this insect, and from the 

 notices of it in the public prints — whilst at the 

 East, where it was so numerous last year, so that 

 except in a few localities, it would not have been 

 noticed had not every body been so eagerly 

 searching for it. 



But though this insect has only been noticed 

 in this country the past and present years, we 

 do not suppose it has newly arrived upon this 

 Continent. It has no doubt been present ia our 

 grain fields heietofore ; but in such limited num- 

 bers, and so scattered about upon the growing 

 grain, that it failed to be observed. It is seven- 

 teen years ago that I began to examine the 

 wheat midge, and in looking at that and other 

 insects upon the wheat, I recollect I have occa- 

 sionally seen this aphis. But as only two or 

 three individuals of this kind were to be found at 

 a time, I tupposed it to be of no importance, and 

 thus gave no attention to it, until it began to ap- 

 pear in such abundance the past year. 



Although it is a common habit of plant lice to 

 become extremely numerous, at times, upon the 

 particular k-nd of vegetation which they respec- 

 tively infest, we meet with no recorded instance 

 in which one of these insects has been known to 

 besome so suddenly and excessively multiplied 

 over such a vast extent of territory as has hap- 

 pened in our country with this grain aphis the 

 past and present years. 



I suppoFe almost every person in this audience 

 has seen these insects, crowded together upon 

 the heads of wlieat, of oats, barley, or rye, and 

 has obsorvd (hat they were a kind of plant- 

 louse, similar to what we frequently see upon 

 the leaves of cabbage in our gardens, and on the 

 apple, the cherry, and other trees. As it resem- 

 bles these common and well-known insects so 

 closely in its form, its motions and habits, it will 

 not be necessary for me to give any particular 

 description of it. 



With regard to the mode in which it injures 

 the grain, I would observe that it has a slender, 

 sharp pointed bill or trunk, which it holds under 

 its breast when this implement is not in use. 

 With this it punctures the leaves and stalks of 

 the grain and sucks their juices. It therefore 

 has no occasion to leave the particular plant oti 

 which it is born, as it always has an ample store 

 of nourishment directly under its feet. Hence, 

 it has ne use for wings to carry it. like other in- 

 sects, from place to place in search of food. It 

 needs wings for only one purpose, namely, to en- 

 able it to emigrate to fields of grain which are 

 unoccupied, in order to start colonies in them. 

 Only a small portion of these insects, therefore, 

 acquire wings ; and these flyaway from the win- 

 ter grain to plant their race upon ^the springs 

 sowed wheat and oats. 



The latter part of June, when the grain has 

 advanced so taat the heads or ears begin to put 

 forth, two most remarkable changes occur in this 

 insect, whereby it begins to become another 

 creature, a difi"erent species, in the middle of 

 summer from that which is seen in the spring 

 and autumn. 



One of these changes is in its habits. Before 

 the heads appear, it lives singly, scattered about 

 upon the leaves and stalks of the grain, and the 

 young lice, as fast as they are born, leave their 

 parents and wander away. But no sooner are 

 the heads protruded from their sheaths prepara- 

 tory to blooming and growing the kernels of the 

 grain, than this aphis wholly forsakes all the 

 other parts of the plant and becomes congrega- 



