452 FRUIT INSECTS 



grubs become full-grown the first season ; others complete 

 their growth the following spring. When ready to transform, 

 the grubs ascend to within four to eight inches of the surface, 

 and there construct earthen cells in which the transformation 

 to the white helpless pupa takes place. In about two weeks 

 the pupa changes to the adult, which, after a few days required 

 for hardening, burrows to the surface and begins its depreda- 

 tions on the leaves. There is only one brood a year. 



Treatment. 



Thorough stirring of the soil to a depth of six inches close 

 around the vine at the time the pupae are in their earthen cells will 

 break many of the cells and kill a large proportion of the pupa?. 

 By keeping the ground around the vine mulched in the spring, 

 the moisture will be conserved, and the grubs will be more hkely 

 to come nearer to the surface for pupation. This treatment 

 cannot be expected to fully control the root-worm, but should 

 be used in connection with thorough spraying to kill beetles. 



The beetles feed on the upper surface of the leaves for about 

 two weeks before beginning to lay their eggs and may be killed 

 at that time by a thorough apphcation of arsenate of lead, 10 

 pounds to 100 gallons of water. When only a few vines are 

 attacked, it is feasible to capture the beetles by jarring the vines 

 over a canvas-covered frame or beetle-catcher. 



References 



Mayet, Les Insectes de la Vigne, pp. 321-332. 1890. 

 Cal. Agr. Exp. Sta. Bull. 195. 1908. 



The Grape-vine Root-borer 



Memythrus polistiformis Harris 



The roots of both the wild and cultivated varieties of grapes 



are subject to the attacks of a large whitish borer, the larva 



of a beautiful wasp-Uke, clear-wing moth. The species ranges 



from Vermont to Minnesota and southward to South Carohna 



