56 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Just beyond this strip of continuous vineyard, however, toward 

 Moorheadville, Pa., the vineyards are more scattered and the acreage 

 surrounding them is devoted to the more general forage crops, such 

 as grass, rye, corn, and other grains, together with considerable areas 

 of unbroken pastures and woodlots. These scattered vineyards have 

 always been menaced by the invasions of this pest from their adja- 

 cent breeding grounds and serious injury has frequently resulted to 

 the grape crop. 



The prevalence of the rose-chafer over this latter section has done 

 much to discourage the planting of new vineyards, the general im- 

 pression being that the insect can not be successfully or economically 



controlled. Handpicking the 

 beetles has heretofore been 

 the only control method em- 

 ployed, and has proved not 

 only tedious and expensive, but 

 only partially effective. It was 

 upon vineyards in this "rose- 

 bug " x infested area along: 

 the lake shore that the spray- 

 ing experiments of the season 

 of 1910 were undertaken. 



HABITS OF THE LARVA. 



The larval stage of the in- 

 sect (fig. 18, b) is spent under 

 ground, usually anions; the 

 roots of grains and grasses. 

 The female beetle (fig. 18, a) 

 burrows into the sandy soil 

 and deposits her eggs singly 

 in small cells in the sides of 

 the burrow. These burrows 

 may be from 1 to 6 inches in depth, and the eggs are deposited irregu- 

 larly in small cells in the walls of the burrow, the shallowest about one- 

 fourth of an inch from the surface, the deepest about 4*inches below. 

 The newly hatched larva? may exist for some time on decayed vege- 

 tation in the soil, but they soon attack the roots of grasses and other 

 plants, and are seldom found in large numbers in soil receiving 

 clean culture. They are, however, quite common in ill-kept sod- 

 covered vineyards, and in digging about the roots of grapevines for 

 other insects single specimens of rose-chafer larva? are found occa- 



Fig. 19. — Work of the rose-chafer : a, Cluster 

 showing small berries of grape injured by 

 feeding of rose-chafer ; 5, berry almost eaten ; 

 c, large berry slightly injured when small, 

 showing seed protruding. (Original.) 



1 A local name for the rose-chafer (Ifacrodactylus subspinosus Fab.). 



