THE TURNIP CROP. 317 



the green portion j wire- worms ?'. e., the larvse of various 

 click beetles (Elateridce) [all vermiform creeping things of 

 the earth are wireworms^ in the farmer's zoology J], centi- 

 pedes, and weevil beetles must be added to the long cata- 

 logue of turnip enemies. 



117. " When we reflect on this formidable list of destruc- 

 tive agents in the form of insects, and add to its various 

 fungi, which live parasitieally upon the leaves (such as Pero- 

 nospora parasitica, a species allied to the potato mould, 

 and a kind of Oidium [Erysiphe], which covers the leaves 

 with its innumerable interlacements, looking like delicate 

 threads of frosted silver, under the microscope), it would 

 seem almost to be a matter of wonder that turnips ever 

 come to perfection at all in this country." 



118. (a) Of the insect enemies of the crop, the turnip-fly, 

 as it is generally called, is the most to be dreaded. Al- 

 though so called, it is not a fly, but a beetle of the size of 

 a flea, and known to naturalists by the name of Haltica 

 nemorum. According to the entomologist, there are, says 

 Mr. Thomas Morris who read a paper on the subject be- 

 fore the Loughborough Agricultural Society there are " at 

 least two species of the turnip beetle, viz., the Striped, and 

 Brassy or Tooth-legged : the latter is not so common as 

 the former, and it appears that scarcely anything is known 

 of the economy of this insect ; but it is the striped beetle 

 with which we, as farmers, are so familiar, and upon which 

 I desire more particularly to claim your attention. It has 

 various names in this country, such as the beetle, fly, black- 

 jack, flea, &c., but upon close examination there can be no 

 doubt that it is a beetle, for it has two sets of wings the 

 outer ones, like all other beetles being of a horny nature ; 

 and to distinguish it from others of its order, I may observe 

 that its colour is a bright-black, with a light-yellow coloured 

 stripe down each outer wing. Mr. Curtis, who has so ably 

 contributed to the Journal of the Eoyal Agricultural Society 

 of England, in his observations on the natural history of 

 insects affecting the turnip crop, informs us that this beetle 

 belongs to the order Coleoptera, from its wings being folded 



