THE TURNIP-FLEA 



41 



Some weevils, some sawflies, many moths and two-winged 

 flies do the same in their larval stage. The leaves of the 

 oak, holly, bramble, and feverfew are often attacked in this 

 way, as are a 

 multitude of other 

 plants. Each spe- 

 cies of insect, as 

 ,a rule, infests one 

 particular plant 

 only. The burrow 

 usually begins as 

 a scarcely visible 

 line, and widens 

 with the growth of 

 the larva; at the 

 broad end may 

 often be seen an 

 enlarged chamber 

 in which the jpupa 

 rests. 



The larva of 

 the flea-beetle only 

 feeds for about a 

 week; it then de- 

 scends two or three 

 inches into the 

 earth to pupate, 

 and emerges after 

 about another fort- 

 night. In the 

 height of summer 

 a new generation 

 is produced every 

 month. 



This beetle is 

 one of those that 

 are voracious in the final or winged stage. Whether an 

 insect feeds busily after it has got its wings, feeds moderately 

 and occasionally, or does not feed at all, is a question that 

 depends very largely upon its manner of egg-laying. On a later 

 page we shall attempt to guide the reader to a solution. 



Fig. 32. — Turnip-leaf, mined by larva: of turnip-flea. 

 From Curtis' "Farm Insects." a, burrows of larvae; 

 ^, male beetle ; c, female beetle ; d, holes made by beetles. 



