16 NEW YORK STATE MUSEUM 



July 2, while in 1903 a few were taken June 19. Their first 

 appearance was on light soil, and the insects did not begin to 

 emerge in numbers on heavy land till nearly a week later. Our 

 cage experiments [see table on p. 27] show that over 92$ of the 

 beetles appeared within two weeks after the first were taken, 

 and practically none after July 21. In other words, out 

 of 506 bred from under two vines, 477 emerged by July 21. 

 The issuing of the insects is undoubtedly considerably modi- 

 fied by temperature, as demonstrated by the beetles appearing in 

 unusually large numbers on the 26th, which was a bright, warm 

 day. The time of appearance and the fact that a large propor- 

 tion of the insects issue from the ground within two weeks are 

 of much importance, if anything is to be done by collecting the 

 insects. The beetles appear to emerge and remain on the foliage, 

 particularly around buds, several days before they feed to any 

 extent. Breeding cage experiments have fixed this period at from 

 one to four days. Two beetles which actually emerged under 

 observation refused food till the fourth day, and it is very prob- 

 able that this period is nearly the normal time between the 

 emergence of the beetles and feeding. A considerable number 

 may be found before any feeding has taken place, as is evidenced 

 by Mr Barden taking 12 from a vine which bore practically no 

 marks of their eating. The insects may be found in a field over 

 an extended period, which is not surprising in view of the fact 

 that a beetle may live over nine weeks, as demonstrated by us 

 this year. Some were observed by Mr T. T. Neill Sep. 4, 1902, 

 in a vineyard at Fredonia, and Mr F. A. Morehouse states that 

 he met with individuals in October 1902. 



Oviposition does not occur till some days after the appear- 

 ance of the perfect insects, and according to breeding cage obser- 

 vations this period may range from 10 to 17 days. Our breeding 

 cage experiments also indicate that the insect may feed from 

 6 to 13 days before eggs are deposited. This period was carefully 

 ascertained by isolating a series of males and females and pro- 

 viding them with as nearly natural conditions as possible. Both 

 of these periods are much longer than normal, since eggs were 

 found by Mr Barden in the Northrop vineyard July 9, 1902, 

 where beetles were present in very small numbers on the 2d. 

 This allows a maximum of only seven days between the appear- 



