INDIRECT INJURIES CAUSED BY INSECTS. 91 



up the stems at night in vast numbers to get at it. The Rev. G. T. Rudd, 

 when residing at Kimpton near Andover, Hants, where this insect abounds, 

 not only saw it, as did his brother, gnaw off the tip of the husk from the 

 end of a grain of barley, and then gradually draw the milky grain out of 

 its sheath, consuming it as it came forth, till the whole grain had disap- 

 peared, and repeating the operation till seven or eight grains had been 

 eaten, but was fully satisfied, on killing and dissecting it, that it had fed on 

 the juicy immature grain. 1 Along with the larvas of this insect were 

 found in the proportion of about one fourth, those of another beetle 

 (Melolontha riificarnii), which seemed to contribute to the mischief. 3 

 Other beetles, generally supposed to be carnivorous, as Amara communis 

 trivialis, &c., are also stated by M. Zimmermann to feed on wheat. 3 



The caterpillars of a moth (Agrotis segetuni) occasionally devastate large 

 tracts of wheat and rye by eating the roots, stem, and leaves, in Northern 

 Germany, Prussia, Poland, and Russia 4 ; but this species with us is 

 chiefly injurious to turnips and garden vegetables. 



Mr. Markwick has given us the history of a fly that attacks wheat in a 

 later period of its growth, which, if it be not indeed the same, appears to 

 be nearly related to the Musca pumilionis of Bierkander 5 (Oscinis F.), 

 accused by him of being extremely injurious to rye in the spring. Our 

 insect was discovered on the tirst-sown wheats early in that season, mak- 

 ing its lodgement in the very heart of the principal stem just above the 

 root, which stem it invariably destroyed, giving the crop at first a most 

 unpromising appearance, so that there seemed scarcely a hope of any 

 produce. But it proved in this and other instances that year (1791) that 

 the plant, instead of being injured, derived great benefit from this circum- 

 stance; for, the main stem perishing, the root (which was not hurt) threw 

 out fresh shoots on every side, so as to yield a more abundant crop than 

 in other fields where the insect had not been busy. These flies, therefore, 

 seem to belong to our insect benefactors ; and I should not have intro- 

 duced them here, had it not been probable that in some instances later in 

 the spring they may attack the lateral shoots of the wheat, and so be in- 

 jurious. It is also not unlikely that the new progeny, which is disclosed 

 in May, may oviposit in barley or some other spring corn, which would 

 bring the next generation out in time for the wheat sown in the autumn. 

 These flies are amongst the last, and, in some seasons, the most numerous, 

 that take shelter in the windows of our apartments when the first frosts 

 indicate the approach of winter, previous to their becoming torpid during 

 that season. When this little animal was first observed in England, it 

 created no small alarm amongst agriculturists, lest it should prove to be 

 the Hessian fly, so notorious for its depredations in North America ; but 

 Mr. Marsham, by tracing out the species, proved the alarm to be un- 



1 Ent. Mag. ii. 182. 



8 Germar's Mag. der Ent. i. 1 10. Mr. Stephens, in his Illustrations of British 

 Entomology ( No. I. p. 4. ) very j udiciousl y asks, '* May not these herbivorous larvae have 

 been the* principal cause of the mischief to the wheat, while those of the Zabrus 

 contributed rather to lessen their numbers than to destroy the corn?" But this 

 query does not account for their being found, when in the perfect state, attacking 

 the ear. I have seen cognate beetles devouring the seeds of umbelliferous plants. 



3 Silbermann, Rev. Ent. ii. 201. 



* Kollar on Ins. injurious to Gardeners, &c. 94 101. 



5 Act, Stockh. 1778, 3. n. 11. and 4. n. 4. Marsham in Linn. Trans, ii. 79. 



