THE STATE ENTOMOLOGIST. 



101 



THE CUCUMBER FLEA-BEETLE— Haltica cucumerU.*— Harris. 



(€oleoptera, Chrysomelidae.) 



This minute Beetle (Fig. 45) belongs to the Flea-beetles (Haltica 

 tFig. 45.] faiaily), the same sub-group of the Leaf-beetles {Phytophaga) 

 l\^ to which also appertains the notorious Steel-blue Flea-beetle 

 -{Haltica chalybea, Illiger), that is such a pest to the vineyard- 

 ist. Like all the rest of the Flea-beetles, it has its hind thighs 

 greatly enlarged, which enables it to jump with much agility. It is 

 not peculiar to the potato, but infests a great variety of plants, includ- 

 ing the cucumber, from which it derives its name. It operates by 

 eating minute round holes into the substance of the leaf which it at- 

 tacks, but often not so as to penetrate entirely through it. In South 

 Illinois whole fields of potatoes may often be observed looking seared 

 ana yellow, and with their leaves riddled with the round holes made 

 by this insect. The larva feeds internally upon the substance of the 

 leaf, like that of the closely-allied European Flea-beetle of the turnip 

 {Haltica nemorum,, Linn.); and, from its near relationship to that in- 

 sect, we may infer that it goes underground to assume the pupa state, 

 that it passes through all its stages in about a month, and that there 

 are two or three broods of them in the course of the same season. 



TEE COLORADO POTATO-BEETLE— Doryphora IQ-lineata, Say. 

 (Coleoptera, Chrysoraelidse.) 



ITS PAST HISTORY AND FUTURE PROGRESS. 



Up to the autumn of 1865, it was generally supposed by economic 

 entomologists, that this destructive insect had existed from time imme- 

 morial in the Northwestern States, feeding upon some worthless weed 

 or other; and that of late years, from some unexplained cause, it had 

 all of a sudden taken to attacking the potato-plant In October, 1865, 



* Erroneously considered by some authors as identical with the Haltica pubesrei.s of Illiger. 

 En this last species, according- to Dr. J L. LeCoote, the thorax, instead of he'mg shining-, as m our 

 EEsect, is opaque, with, large- (lease pi*ncture.s. 



