94 Observations on the various Insects 



teeth between them, with 2 tubercles below^ and 2 fleshy pro- 

 tuberances capable of dilatation and contraction, which materially 

 assist the mag-gots in locomotion, and in the centre of the stern 

 are 2 large spiracles (fig. y?). In the spring they change in the 

 earth to pupae of the like dirty colour, these are about the same 

 length as the larvae, but scarcely so stout. At this period the 

 head and thorax of the future gnat are defined, but from each 

 side of the latter projects a short slender horn, and beneath the 

 horny case the incipient wings are visible, with the legs placed 

 between them : the abdominal segments have each a trans- 

 verse row of minute spines above, and 5 large ones beneath, 

 and on either side is an elevated spiny line ; the penultimate 

 segment is surrounded by 6 longer spines and 2 small ones, 

 with a large conical process at the tail and a shorter one beneath 

 it (fig. 44). 



To ascertain the parents of these grubs or maggots, I paid great 

 attention to them for several years^, and some idea may be formed 

 of the mischief they occasion in the field, by the ravages they com- 

 mit in the garden. On the 23rd of April I found these grubs at 

 the roots of my peas ; on the 29th, some had eaten off trusses of 

 the strawberry flowers close to the crown, retiring afterwards just 

 beneath the surface of the earth, and I think it was the same, or 

 the larvse of T. Oleracea, which used to cut through the runners of 

 the same plants : the first week in May they were not uncommon 

 amongst the roots of the lilacs and under tufts of grass ; they were 

 also destroying the strawberry and raspberry plants as well as the 

 carrots : on the 28th of the same month I observed some recently 

 transplanted lettuces drooping, and on examination I found the 

 roots separated from the crown a little below the surface, and close 

 by these grubs, which are difficult to detect, owing to the colour 

 and their remaining quite motionless when disturbed. At the end 

 of July they were eating the roots of dahlias, carnations, and va- 

 rious flowers, and on the 7th of August they were observed infest- 

 ing some potato ground with the larvae of T. Oleracea ; after which I 

 lost sight of them.* 



We learn, from the ' Introduction to Entomology,' that these 

 larvae abound in some seasons in Holderness to such an extent, 

 that hundreds of acres of pasture were destroyed by them in the 

 spring of 1813. ''A square foot of the turf being dug up, 210 

 grubs were counted in it ;" t and wheats there when sown upon 

 clover-lays suffer severely from these grubs. 



Lime-water, it is now said, will not kill these tough larvae, as it 

 will the thin-skinned earthworm, and the only remedy I have prac- 



* Gardeners' Chron., vol. vi. p. 317. 



t Kirby and Spence, 6th edit. vol. i. p. 148. 



