affecting the Pea-crops, Mangold-wurzel, and Beet. 41 1 



men whitish, and along the back are two jellowish-white stripes 

 (fig. 26).''' In less than a fortnight, viz,, about the beginning of 

 August, the CassidaB hatch. 



They belong to the Order Coleoptera, Family Casbid^, 

 and Genus Cassida, or Shield-Beetles, and this species vvas 

 named by Linnaeus — 



4. C. nebulosa. When first developed it is green, but it gradually 

 becomes of a tawny colour above and black beneath (fig. 21 ; the na- 

 tural length) ; the little head is concealed under the large semi-orbicLdar 

 thorax, which is stamped with minute impressions, having two white 

 spots at the base; the black eyes are oval ; the horns are inserted on the 

 forehead, and are 1 1 -jointed, shghtly thickened, and blackish towards 

 the extremity, which is pointed ; the scutellum is rather small and tri- 

 angular; the wing-cases are oval and convex, with a flattened margin ; 

 there are five double rows of punctures on each, with black dots sprinkled 

 over them : the two wings folded beneath are ample : the legs are short ; 

 the feet are 4-jointed, with the third joint bilobed, the fourth furnished 

 with a pair of claws.t 



The larvae sometimes fall victims to a parasitic fly, notwith- 

 standing the protection we have alluded to ; for M. Guerin says, 

 one which was not transformed to a pupa, produced, on the 25th 

 of July, from the middle of the back, thirty-nine very little Chal- 

 cidites,^ black, with yellow legs, the eggs of which had been de- 

 posited by the mother upon the living larva. 



Altica Nemorum. The Turnip Beetle or Fly. 



Since my Essay upon this insect was written, § I have detected 

 the little beetles hopping about the mangold-wurzel and punctur- 

 ing the leaves. Mr. Kootsey of Bristol has also made the same 

 observation. 



Anthomyia Bet^. The Mangold-wurzel Fly. 



It is generally supposed that animals closely related to each 

 other, and forming a natural group, would not be very unlike in 

 their habits of life, but such is not always the case amongst in- 

 sects, in their larva state especially, and the genus of flies called 

 Anthomyia is a remarkable example of such a diversity. There 

 are several species that annoy the farmer and gardener, which 

 bear so striking a resemblance to each other in their fly state, that, 

 except to the scientific observer, they would be considered as the 

 same species, yet nothing can be more different than the economy 

 of the larvae. Some of these maggots live upon the seeds of the 



* De Geer's Hist, des Ins., vol. v. p. 168. 



t Vide Curtis's Brit. Ent., fol. and pi. 127, for fignies and dissections. 

 % Annales de la Soc. Ent. de France, for 1846, p. ]xxi. 

 § Journal of Royal Agric. Soc, vol. ii. p. 193. 



