182 INDIRECT INJUniES CAUSED BY INSECTS. 



as the inventor of a machine to entrap the turnip- 

 beetle, which may be applied by collectors M'ith great 

 advantage to general purposes,) has also succeeded in 

 tracing this insect from the larva to the imago state. 

 His grubs produced Elatcr ohscunis of Mr. Marsham, 

 which however comes so near to E. Segetis that it is 

 doubtful whether it be more than a variety. The other 

 species, however, of the genus have similar grub?, 

 many of which probably contribute to the mischief. 

 When told that it lives in its first (or feeding) state 

 not less than five years, during the greatest part of 

 which time it is supported by devouring the roots of 

 grain, you will not wonder that its ravages should be 

 so extensive, and that whole crops should sometimes 

 be cut oft" by it. As it abounds chicjly in newly broken- 

 up land, though the roots of the grasses supply it with 

 food, it probably does not do any great injury to our 

 meadows and pastures*, 



' The wire-worm is particularly dcsfnicfive for a few year? in gar- 

 dens recently converted from pasture ground. In the Botanic Garden 

 at Hull thus circumstanced a great proportion of the annuals sown in 

 1813 were destroyed by it. A very simple and effectual remedy in such 

 cases was mentioned to me by Sir Joseph Banks. He recommende 

 that slices of potato stuck upon skewers should be buried near tiie seeds 

 sown, examined every day, and the wire-worms whicii collect upon them 

 in great numbers destroyed. 



This plan of decoying destructive animals from our crops by ofF^riig 

 them more tempting food, is excellent, and deserves (o be pursued in 

 other instances. It was very successfully employed in 1813 by J. M. 

 Ilodwell, Esq. of Barham IlaJl near Ipswieh, one of the most skilful 

 and best iuforn»ed agrirulturists in the county of Suflolk, to preserve 

 some of his wheat-fields from the ravages of a small gray slug, which 

 threatened to demolish the plant. Having heard that turnips had been 

 used with success to entice these slugs from wheat, he eauwd a sutficiert 

 quantity to dress eight acres to be got together j and then, the topfe being 



