92 INDIRECT INJURIES CAUSED BY INSECTS. 



founded.^ That there was sufficient cause for apprehension, should fi: 

 have so turned out, what I have formerly stated concerning; the hitter insect, 

 and the additional facts which I shall now adduce, will amply show. 



The ravages of the animal just alluded to, which was first noticed in 

 1776, and received its name from an erroneous itlea that it was carried by 

 the Hessian troops in their straw from Germany, were at one time so 

 universal as to threaten, where it appeared, the total abolition of the cul- 

 ture of wheat ; though the injury which it now occasions is much less 

 than at first. It commences its depredations in autumn, as soon as the 

 plant begins to appear above ground, when it devours the leaf and stem 

 with equal voracity until stopped by the frost. When the return of spring 

 brings a milder temperature the fly appears again, and deposits its eggs in 

 the heart of the main stems, which it perforates, and so weakens, that when 

 the ear begins to grow heavy, and is about to go into the milky state, they 

 break down and perish. All the crops, as far as it extended its flight, fell 

 before this ravager. It first showed itself in Long Island, from whence it 

 proceeded inland at about the rate of fifteen or twenty miles annually, and 

 by the year 1789 had reached 200 miles from its original station. I must 

 observe, however, that some accounts state its progress at first to have 

 been very slow, at the rate only of seven miles per annum, and the damage 

 inconsiderable ; and that the wheat crops were not materially injured by 

 it before the year 1788. Though these insect hordes traverse such a 

 tract of country in the course of the year, their flights are not more than 

 .Ave or six feet at a time. Nothing intercepts them in their destructive 

 career, neither mountains nor -the broadest rivers. They were seen to 

 cross the Delaware like a cloud. The numbers of this fly were so great, 

 that in wheat-harvest the houses swarmed with them, to the extreme 

 annoyance of the inhabitants. They filled every plate or vessel that was 

 in use ; and five hundred were counted in a single glass tumbler exposed 

 to them a few minutes with a little beer in it.^ 



America suffers also in its wheat and maize from the attack of an insect 

 of a diflSerent order ; which, for what reason I know not, is called the 

 chintz bug-fly. It appears to be apterous, and is said in scent and colour 

 to resemble the bed-bug. They travel in immense columns from field to 

 field, like locusts, destroying every thing as they proceed ; but their injuries 

 are confined to the states south of the 40th degree of north latitude.^ 

 ?rom this account the depredator here noticed should belong to the 



1 Linn. Trans, ii. 76—80. 



8 Encydopced. Britann. viii. 489 — 495. Though the ravages of the Hessian fly in 

 the United States have not been so extensive of late, much injury is still occasional!}' 

 suffered from it, as stated by Mr. Say, who described it under the name of Cecido- 

 myia destnictor, and as I learn from E. C. Herrick, Esq. of Xew Haven, Connecti- 

 cut, who has taken great pains to ascertain the metamorphosis and economy of this 

 insect; and either this or an allied species described by jM. Kollar, destroyed a large 

 proportion of the wheat crops in Hungary in 1833, and extended itself also to 

 France. Dr. Hammerschmidt, who has also given an account of this insect, has 

 called it Cecidomyia tritici, supposing it to be the same with the insect described by 

 Mr. Marsham and I\Ir. Kirby ; but as the mischief done by the larva of the former 

 is caused by its eating into the stem and weakening the whole plant, while the 

 latter is injurious by destroying the pollen of the blossom, the two insects are evi- 

 dently very distinct, as indeed their different colour proves. — Kollar on Ins. injurious 

 to Gavdenery, &c. 118. 



3 Young'si .4«wa/s of Agriculture, xi. 471. 



