PESTS OF THE HOP CROP. 139 



fly against the kcroscned or tarred surface, and arc thus 

 destroyed in large numbers. 



BEETLES KEK1HX(J OX HOI' LEAVES 



Several species of leaf beetles are frequently found 

 in the hop yards, and gnaw holes in the leaves, thus 

 disfiguring them, but seldom injuring the plant. 

 Among these are the red-headed ilea-beetlc {Systoui 

 frontalis), the striped flea-beetle {Phyllotrcta vittata), 

 the punctured flea-beetle (Psyllioiks piinctulata), a.nd the 

 twelve-spotted leaf beetle (Diabrotica \2-pwictata). 

 These species were found by Dr. Smith at Waterville. 

 Mr. Pergande, at Richfield Springs, collected Ph\llo- 



FIG. 71. STRIPED FLEA-BEETLE, 

 a, Larva; 6, adult. Enlarged. (From U. S. Department of A^'riculture.) 



trcta vittata; Crcpidodcra Jiclxiucs, the common willow 

 flea-beetle; Epitrix cncumcris, the potato Hea-beetle; 

 Diabolia borcalis, the common plantain leaf miner; Psyl- 

 liodcs puuctulata, a common and widespread species. 

 None of these insects is peculiar to the hop plant. 

 The common striped flea-beetle is shown in the accom- 

 panying figure. 



THE SO-C.\LLED "RED SPIDER," OR SPIXXTXa MITE 



Hop fields in England have occasionally suffered 

 to a considerable extent from the damage done to the 



