256 INSECT TRANSFORMATIONS. 



stroyed by them, being rendered as completely brown 

 as if they had suffered a three month's drought, and 

 destitute of all vegetation except a few thistles. A 

 square foot of the dead turf being dug up, 2lO grubs 

 were counted on it; and, what furnishes a striking 

 proof of the prolific powers of those insects, last year 

 it was difficult to find a single one.'* 



It is worthy of remark that the mandibles of these 

 destructive creatures, which are claw-shaped and 

 transverse, do not act against each other as is usual 

 among insects, but against two other pieces which are 

 immoveable, convex, and toothed, as if the under- 

 jaw in quadrupeds were divided into two, and should 

 act vertically on the two portions of the immoveable 

 upper-jaw thrown in between them. 



The maggot of a minute fly of the same family, 

 known by the name of the wheat fly ( Cecido- 

 myia Tritici, KIRBY), is frequently productive of 

 great damage in the crops of wheat. Its history was 

 first investigated by Marsham, and subsequently by 

 Kirby, and several other intelligent naturalists. The 

 parent fly is very small, not unlike a midge ( Culicoi- 

 des punctata, LATH.), of an orange colour, and wings 

 rounded at the tip, and fringed with hairs. f The 

 female is furnished with a retractile ovipositor, four 

 times as long as the body, and as fine as a hair, for 

 depositing her eggs, which she does in the glumes 

 of the florets of the grain. The following account of 

 its proceedings is given by Mr Shireff, an intelli- 

 gent farmer of East Lothian. 



* Wheat-flies,' he says, ' were first observed here 

 this season on the evening of the 21st of June, and, 

 from the vast number seen, it is probable a few of 

 them may have been in existence some days previous. 



* Intr. i, 318, note, 

 t Linn. Trans., iii, 234 iv, 243-240; v. 96. 



