THE TURNIP-FLEA. 211 



though individually small and insignificant, collectively exer- 

 cise very great influence upon the agriculture of our country. 

 One of these insects is shown on Woodcut XXIII. Fig. 2, and 

 is one of several Beetles which are known by the pop\dar name 

 of TuuNir-FLEAS or HoprEUS. It is called scientifically Phyllo- 

 treta (or Halt lea) brass lew. 



All the Halticidse can be distinguished by the very thick 

 hinder femora, which denote the possession of great leaping 

 powers on the part of the insect. The antennae are set between 

 the eyes, and the edges of the elytra are wavy. They are 

 attached to different plants, and are so constant to them that 

 their specific names are often taken from their food-plant. 

 The colour of the present species is deep-black, and there are 

 two longitudinal yellow streaks upon each of the elytra, one 

 near the base, and the other towards the apex. The body is 

 egg-shaped, and the elytra are rounded at their tips. It is 

 about the smallest species of the genus. 



The true Turnip-flea is another species, called Phyllotreta 

 netnorum, the colour of which is black, with a broad longitu- 

 dinal yellow streak running nearly, but not quite, to the end 

 of the elytra. Both in the larval and perfect stages this insect 

 is extremely damaging to the turnips, feeding upon the first 

 tender shoots as they appear above the ground, and so destroy- 

 ing the whole plant. Sometimes they will devastate a field so 

 completely, that it must be re-sown if a crop be wanted. The 

 early life of this Beetle has been well told by Mr. Le Keux, in 

 the ' Transactions of the Entomological Society,' vol. ii. After 

 narrating the destruction which these insects had wrought, he 

 proceeds as follows : — 



* Being still at fault as to the origin of the larvaB, I captured 

 ten males and ten females in pairs, and enclosed them in a 

 glass tube covered at each end with wire gauze, into which I 

 introduced a single leaf of turnip, with water to keep it fresh ; 

 by this means I was enabled to examine the insects and leaf 

 on all sides with a magnifying-glass at any time without dis- 

 turbing them. Having, previous to introducing the leaf, 

 ascertained with a strong magnifier that there were no eggs 

 or larvae upon it, on the following day I had the satisfaction 

 to perceive five small, smooth, oval-shaped eggs adhering to 

 the under side of the leaf, and so nearly resembling it in 



