222 BRITISH BEETLES. 



The species of Phyllotreta are especially addicted to 

 tlie destruction of cruciferous plants; certain of them 

 being known as the "Turnip-flea" or " -fly," on account 

 of their ravages upon that vegetable, the leaves of which 

 are both mined by their small elongate dotted larvse, 

 and devoured by the perfect insect. They are mostly 

 black ; often having on the elytra yellowish- white stripes, 

 which are sometimes divided into spots. The male of 

 P. nodicornis, a linear bronze-coloured insect, most 

 abundant on Reseda lutea (wild mignonette), is remark- 

 able for the abrupt, flattened, and exceedingly conspicu- 

 ous plate formed by the fourth joint of its antennae ; and 

 P. ochripes (Plate XV, Fig. 1), found on the Alliaria, 

 is the most gaily ornamented in the genus. The striped 

 species are often very troublesome to beginners, but are 

 readily separated by the following characters : vittula, 

 very small and the most parallel, has an almost straight 

 stripe, which is abruptly and obliquely sloped inwards 

 at its upper extremity by the shoulder ; undulata, larger, 

 and rather less straight- sided, has the stripe gently hol- 

 lowed out or waved in the middle on the outer side, and 

 slightly and gradually sloped off" at the shoulder ; nemo- 

 rum, usually considered as the " Turnip-flea," though not 

 nearly so common as undulata, is more coarsely punc- 

 tured and larger still, and has yellow tibise, the same 

 parts in the latter insect being infuscated ; tetrastigma 

 is largest of all, very shining black, more convex, and 

 with its stripes (which are of a darker yellow) much con- 

 tracted in the middle, often quite divided, and forming 

 four large spots ; sinuata, very rare (occurring in Suffolk 

 on horse-radish), resembles a small undulata, but has 

 the stripe notched very abruptly both in the middle of 

 the outer side, and at the shoulder ; ochripes has entirely 



