34 BULLETIN 911, U. S. DEPARTMENT OF AGRICULTURE. 



growers. During these investigations the writer has been led to 

 believe that the moths normally prefer to deposit their eggs on the 

 formed grapes rather than on the unopened buds. This was strik- 

 ingly shown in the case of the Clinton vine on which oviposition 

 records were taken for Table XIV. On this single Clinton vine, growing 

 in a row of the Concord variety with the Ives variety close by, were 

 994 grapes bearing eggs on June 29. Subsequently 630 more eggs 

 were recorded on this one vine. Careful search was made on adjoining 

 vines of the other varieties and not until the grapes were well formed 

 could eggs be found, whereas heavy oviposition continued on the Clin- 

 ton vine. Repeatedly vines of the Shrkles variety, the earliest of any 

 to bloom in northern Ohio, have been heavily infested with larvae 

 when adjoining vines of the Concord and Catawba varieties bore no 

 eggs and were not infested. This condition also prevailed where 

 several rows of the Clinton or other early blooming varieties paralleled 

 rows of the later blooming varieties. In years of heavy infestation 

 it is advisable to spray the early blooming varieties earlier than the 

 midseason varieties. 



EGG. 



A single observation was made on the issuance of the larva from 

 the egg, on August 9, 1916. When first observed, the head of the 

 larva was just through the eggshell and 2 \ minutes more were required 

 for the larva to free itself entirely from the shell. The larva did not 

 consume the empty eggshell. 



LARVA. 



Mention is often made of the habit of the first-brood larvse to web. 

 the young grape clusters before or during bloom. In but one instance 

 during three seasons has the writer seen these webbed clusters in the 

 grapes of the mid-season blooming period. Webbing frequently 

 occurs in the Delaware variety which is in full bloom a few days 

 after the Concords and just at the time when the spring-brood moths 

 are emerging in large numbers, as shown in figures 2 and 4. This same 

 condition exists with the Norton variety, which blooms very late. 



The grape-berry moth larvss occasionally feed on grape leaves in 

 the rearing cages even when grapes are present, and in at least one 

 case a larva developed from about one-half size to maturity by feeding 

 in this way. 



LARV^ FEEDING ON PHYLLOXERA GALLS. 



On August 25, 1916, and again on October 2, 1917, vines of the 

 Clinton variety of grape were observed which were heavily infested 

 by the leaf form of the grape phylloxera. Examination of the 

 phylloxera galls showed that they had been eaten into and in some 

 cases much of the gall actually consumed. On these same leaves 

 with the galls were thin white silken webs containing larvss which 



