No. 8. 



Hessian Fly and other Wheat Insects. 



267 



To the Editor of the Farmers' Cabinet. 

 Hessian Fly and other Wheat Insects. 



In the last two numbers, 6 and 7, of the 

 current volume, 5, of the Cabinet, and also 

 in some former volumes, several communica- 

 tions have appeared, treatinjf of the Hessian 

 fly (cecidomyia destructor of Say), but I shall 

 pass them by, inasmuch as the natural his- 

 tory of that insect has, for a considerable 

 time past, been as clearly ascertained as that 

 of any other whatever. The first publication 

 that I know of, is by General J. H. Cocke of 

 Virginia, dated October 1817, which describes 

 the fall deposit ; see American Farmer, Vol. 

 T., p. 296. The second is by myself, dated 

 1st February, 1820, also describinsf the fall 

 deposit; see same work, Vol. TI., p. 180. The 

 third is by Dr. Isaac Chapman, communi- 

 cated to the Agricultural Society of Bucks 

 County, 14th August 1820, said to have been 

 written in 1797, stating its appearance in 

 Bucks County in 1786, and its progress for 

 some time afterwards ; also describing its se- 

 veral changes and habits ; but the Doctor has 

 only noticed two generations, having blended 

 the second and third together ; see Memoirs 

 of the Philadelphia Agricultural Society, 

 Vol. V. The fourth, by myself, dated 12th 

 February, 1821, which traces the history of 

 the insect throughout the year; see Ameri- 

 can Farmer, Vol. III. p. 187. The fifth is by 

 myself, dated 1st June, 1821 ; see same vol- 

 ume, p. 213. The sixth is by myself, dated 

 in 1823, treating of the fly and three other 

 insects injurious to the wheat crop, and pro- 

 posing a remedy; see Memoirs of the Penn- 

 sylvania Agricultural Society, p. 165. 



I refer you to all of the abovementioned 

 papers, particularly the last; but as many of 

 your readers may not have an opportunity of 

 seeing them, I will transcribe what I deem 

 to be essential. 



The Hessian fly, I believe, first made its 

 appearance on Long Island, N. Y., in 1776, 

 or soon after the Hessians were there, and 

 is supposed to have been introduced among 

 some straw which they brought with them ; 

 hence the name ; but the late Judge Peters, 

 that great friend and patron of agriculture, 

 in his notices for a young farmer says, that 

 the insect was unknown in Hesse, " that its 

 name does not prove its importation, for that 

 appellation was bestowed during our revolu- 

 tionary excitements, when every thing we 

 disliked was called Hessian. The insect has 

 been accurately described by Mr. Say and 

 Dr. Chapman ; but Mr. Say was mistaken re- 

 specting the deposit, as the aperture which 

 he noticed in the sheath of the leaf, was oc- 

 casioned by the insect passing into the winged 

 state, and not perforated in the act of depo- 

 siting its eggs. The fly is of a dark colour, 



about the size of the mosquito, and the male 

 much like it except the wings; the body of 

 the female is larger; the wings rest horizon- 

 tally, and where they join the body are al- 

 most pointed, gradually expanding towards 

 the other end, where they form nearly a semi- 

 circle. The egg is scarcely discernible to 

 the naked eye, is oblong, of a pale red or am- 

 ber colour, and placed in the gutter of the 

 leaf, from half an inch to an inch or more 

 from the stalk; the caterpillar, of a pale red 

 colour, is hatched in a few days time (accord- 

 ing to the state of the weather) and passes 

 down the leaf to its junction with the stalk, 

 thence between the sheath and stalk, to near 

 the root or joint ; it there becomes stationary, 

 feeds on the sap of the plant and, being 

 blanched by its covering, is mistaken for the 

 ecrg. The first deposit takes place from the 

 fifteenth to the last of April (as the season 

 may be), changes to the pupa from the first 

 to the middle of May, and evolves in the 

 winged state, the latter part of that month. 

 The second generation commences from the 

 first to the middle of June ; the fly chooses 

 the stunted plants, and deposits both on the 

 top and underneath the upper leaf, and the 

 larvse pass to near the two upper joints, 

 but are found mostly about the upper, and in 

 such numbers as many perish for want of 

 food, the increased number being so dispro- 

 portioned to the plants which suit their pur- 

 pose; I have counted upwards of two hun- 

 dred eggs on a single leaf. The third depo- 

 sit is made in the manner of the first, and 

 commences about the fifteenth or later in Au- 

 gust, and is continued on until cold weather; 

 the irregularity of this generation is occa- 

 sioned by the various situations in which the 

 pupa of the second is thrown, it is lodged in 

 the straw of the stunted plants, so that in 

 harvesting, much of it is scattered about the 

 stubble-fields and the rest is carried to barns 

 or stacked ; such as is early exposed to heat 

 may produce a fourth generation, whilst that 

 which is covered till winter may not give a 

 third. 



On discovering a fly in the act of deposit- 

 ing, I secured it, and on exainination (making 

 the best calculation that I could, and not 

 knowing whether it had deposited any eggs 

 before) I supposed it to contain one hundred 

 eggs; if such be the fact, the first deposit 

 would be one hundred ; the second ten thou- 

 sand, and the third one million, all in the 

 course of one year; happily, however, they 

 have enemies which vastly reduce their num- 

 ber. 



The only plants, according to my observa- 

 tions, which are subject to the depredations 

 of the fly, are wheat, rye and barley ; rye, 

 owing to its early spring growth, is not much 

 injured ; grains should be sown (in this cli- 



