REPORT OP COMMITTEE ON PUBLICATION 207 



of wood, and among deal leaves and rubbish. Here they remain dormant 

 until the warm weather of spring arouses them from their winter's sleep. 

 Entrance into winter quarters takes place about the time the leaves of the 

 grape fall. 



Emergence from hibernation. The first few warm days of spring do not 

 arouse these beetles but when there has been an accumulation of tempera- 

 ture sufficient to bring forth the first dandelion blossoms in sheltered places 

 we expect to find the first beetles feeding in places where they are sheltered 

 from chilling winds. For several seasons observations of the first appearance 

 of the adults have been made and the first blooming dates of common wild 

 plants noted. From these observations we learn that the adults may be ex- 

 pected to appear very near the time of the first blooming of several plants, 

 as follows: dandelion, yellow adders tongue (Erythronium americanum), and 

 gill-over-the-ground (Nepeta hederacea). Early in the spring the beetles 

 may appear during a warm day, then a succession of cold, cloudy days will 

 drive them back to shelter. When the temperature is below 50 F. it is use- 

 less to look for the beetles on the vines. Feeding seldom takes place unless 

 the temperature is above 55 F. Temperatures above 65 will be sufficient to 

 produce extensive feeding and some dispersion although this latter phenome- 

 non takes place more rapidly the higher the temperature at least up to 80. 

 This relation of temperature is seen from the direction of spread in the vine- 

 yard into which the insects have migrated. Here they will infest the por- 

 tion which is best protected from cold winds and therefore is warmer. 



Mating. After feeding for a day or two the beetles begin to mate and this 

 continues during the greater part of a month, some individuals mating over 

 a period of six weeks. In cages the same individuals were observed mating 

 during this period of time. 



Egg deposition. The laying of eggs begins early in May and is continued 

 until near the middle of June. In cages the average length of the egg laying 

 period has been 23 days but one female was observed to oviposit for 52 days. 

 The longest egg laying period for all the females any single season has been 

 53 days. Eggs are laid during the warmer parts of the day and it has been 

 noted that the variations in temperature affects the rate of laying consider- 

 ably during the early part of the season, but only slightly after June 1. The 

 reason for this is found in the fact that by this date the females have laid 

 the greater number of their eggs and the maximum daily temperature is 

 usually above 65. During May we have never found the beetles laying if the 

 maximum temperature for the day was below 60. 



In cages during four seasons in which a large number of beetles were 

 under observation, the mean number of eggs laid by a single female has 

 been 63, the maximum number 164 and the minimum 55. The number of 

 eggs laid per day by a female averaged 3 with a maximum of 25. 



The eggs are generally deposited underneath the loose bark of the canes 

 (Fig. 2a) near the buds but are not tucked under the bark as tightly as are the 

 eggs of the grape root worm. Many of the eggs are placed on the rough area 

 surrounding the buds and some are placed on the growing shoots and even on 

 the leaves. Egg parasites do not attack the eggs to any extent even though 

 exposed. The females place their eggs in these positions so that the young 

 larvae upon hatching will have a short distance to go for food. These newly 



