INDIRECT INJURIES CAUSED BY INSECTS. 137 



America suffers also in its wheat and maize from the attack 

 of an insect of a different order ; which, for what reason I 

 know not, is called the chintz bug-fly. It appears to be ap- 

 terous, 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 5 but their 

 injuries are confined to the states south of the 40th degree of 

 north latitude.^ From this account the depredator here 

 noticed should belong to the tribe of GeocoriscB Latr.; but 

 it seems very difficult to conceive how an insect that lives 

 by suction, and has no mandibles, could destroy these plants 

 so totally. 



When the wheat blossoms, another marauder, to which 

 Mr. Marsham first called the attention of the public, takes its 

 turn to make an attack upon it, under the form of an orange- 

 coloured gnat, which introducing its long retractile ovipositor 

 into the centre of the corolla, there deposits its eggs. These 

 being hatched, the larvae, perhaps by eating the pollen, pre- 

 vent the impregnation of the grain, and thus in some seasons 

 destroy the twentieth part of the crop. ^ 



Much mischief is also sometimes done by a species of 

 Thrips ( T. cereatina Haliday), a minute insect, often abun- 

 dant on flowers, which, insinuating itself between the internal 

 valve of the corolla and the grain, inserts its rostrum into 

 this last, and causes it to shrivel^; and according to Vassal! 

 Eandi'^, as quoted by Mr. Haliday, the same species also at- 

 tacks the stem at a still earlier period, causing the abortion 

 of the ears, and sometimes to such an extent that in 1805 (in 

 which year the wheat in England, also, suffered apparently 



and economy of this insect ; and either this or an allied species described by 

 M. Kbllar, 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 Mr. 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 evidently very distinct, as indeed their dif- 

 ferent colour proves. — Kollar 07i Ins. injurious to Gardeners, &c. 118. 



1 Young's Annals of Agriculture, xi. 471. 



2 Tipula tiitici K., belonging to Latreille's genus Cecidomyia. — Marsham 

 and Kirby in Linn. Trans, iii. 242 — 245. iv. 225 — 239. v. 96 — 110. 



3 Kirby in Linn. Trans, iii. 242. 4 Mern. Acad. Turin, xvi. lxx^■i. 



