272 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



There are two broods during the season, the larvae of the first 

 appearing in June, and those of the second in August; but the 

 beetles of the second brood do not emerge until the following 

 spring. In other respects the life history is practically the same 

 as that of the Colorado potato-beetle. The beetle is of a pale 



yellow color, with 

 three black stripes on 

 its back, and in a gen- 

 eral way resembles 

 the common striped 

 cucumber -beetle 

 (Diabrotica vittata 

 Fab.), though it is 



TK ooo r i- j"I~ri_ X!**/T somewhat larger and 



FIG. 233. Three-lined leaf -beetle (Lema trilineata & 



Oliv.); , larva; 6, pupa; d, eggs; beetle at right, the thorax is decid- 

 (After Riley.) edly CO nstricted. 



In case it becomes necessary to destroy the blister-beetles, both 

 they and the three-lined leaf-beetle may be readily disposed of by 

 applying arsenicals as advised for the Colorado potato-beetle. 



The Potato Aphids * 



The potato aphid, also called the pink and green aphid of 

 the potato because it occurs in both these colors, is a widely 

 distributed pest which occasionally does a considerable amount 

 of injury to the potato. It attacks, beside the potato, the pepper 

 vine and several other unrelated plants. 



The insect is large for an aphid, and may be either pink or 

 green, and lacks the dark markings characteristic of many species 

 of aphids. 



The aphids are found in the spring and early summer feeding 

 on rose bushes and possibly other plants and from these they 

 migrate about mid-summer to potato and other food plants. 

 Both winged and wingless forms migrate, an unusual occurrence 

 as ordinarily only winged individuals take part in the migration. 

 In late summer and early fall the reverse migration takes place. 



Not a great part of the season is spent on the potato but in 

 the time the aphids are present they are able to do a great amount 



* Macrosiphum solanifolii Ashmead. See Dr. Edith M. Patch, Bulletin 

 242, Maine Agr. Expt. Sta. 



