72 INSECTS OF ECONOMIC IMPORTANCE 



CoNTRor. — Tn France American root-stocks are 

 used. 



The grape root-worm - {Fidia viticida) 

 Order — Coleoptera 



The most serious pest of the grape in this state ; 

 probably invaded Chautauqua g'rape region about 

 1899; it is an American insect and widely distrib- 

 uted over the northern half of the eastern United 

 States. 



The adult beetles appear last of June or first of 

 July and begin feeding on leaves making charac- 

 teristic chain-like holes ; about middle of July they 

 begin to deposit eggs in masses under the loose bark 

 on the canes and trunks; the eggs hatch in about 

 two weeks and the larvae drop to the ground where 

 they make their way to the roots through cracks 

 and crevices of the soil; they live upon the roots 

 and become nearly and sometimes full-grown by 

 fall; in November the larvae burrow to a depth of 

 a foot, form cells in the soil and pass the winter; 

 •in early May they return to the roots, feed a short 

 time and change to pupae along in the middle of 

 June ; the partly grown larvae may feed longer ; the 

 pupal stage lasts about two weeks when the adults 

 appear, thus making one generation a year. 



Control — Cultivation about the roots of the 

 vines with a horse-hoe during the first two weeks 

 of June is of benefit in destroying the pupae. If 

 beetles are only moderately abundant, spray vines 

 within one week after beetles are first seen with 6 

 pounds of arsenate of lead in 100 gallons Bordeaux; 

 if beetles abundant, use the sweetened mixture of 

 six pounds arsenate of lead, 100 gallons water and 



2 SHngerland— Cornell Univ. Expt. Stat., Bull. 184. 

 Hammar— U. S. Bu. Ent., Bull. 89. 

 Hartzell— N. Y. State Expt. Stat., Bull. 331. 



