THE" GRAPE CURCULIO. 7 



The records in Table I cover only a portion of the active life of the 

 beetles, and it is certain that the specimens under observation had 

 been feeding on the grape f oliage for at least four weeks just prior to 

 July 9, the day of the first record. It is also reasonably certain that 

 at least a part of the beetles had fed for a time during the previous 

 autumn before going into hibernation. On the day of the first record 

 280 feeding marks were made and the period of greatest feeding 

 activity extended from that date to August 10. This was likewise 

 the period of greatest egg production. On July 30 the beetles made 

 1,085 feeding marks, which was the maximum number, and on July 

 31 they deposited 244 eggs, which was also the maximum number. 

 As is shown by Table I, the total number of feeding marks was 27,227, 

 an average of slightly over 567 for each individual. The aggregate 

 leaf surface eaten over by each beetle averaged slightly more than 2\ 

 square inches and the total surface eaten by all the beetles would 

 cover an area nearly four times the size of the printed portion of this 

 page. 



RELATIVE FEEDING CAPACITY OF THE SEXES. 



During the egg-laying season the food consumed by a female in 

 excavating her egg chambers is considerable, often surpassing daily 

 in weight that of the insect itself. It was thought possible that the 

 amount of fruit pulp eaten in this operation would result, for the 

 time at least, in a decreased amount of leaf feeding by the females 

 and render them less susceptible to arsenical sprays than are the 

 males. Experiments, however, showed that the females do not 

 decrease their leaf feeding during the oviposition period, and that, 

 on the contrary, during days when egg production is heaviest leaf 

 feeding may increase rather than diminish. 



For a period of 14 days, from August 8 to August 21, 3 male and 

 3 female beetles were confined in cages separately and supplied daily 

 with fresh grape leaves and fruit. During the period the males 

 made 251 feeding marks, an average of 83.66 each, while the females 

 made 313 marks, an average of 104.33 each. In addition, the 3 

 females excavated 125 egg chambers. The individual female which 

 laid the greatest number of eggs made, also, the greatest number of 

 feeding marks, the numbers being 54 eggs and 172 feeding marks. 

 In another experiment, while 5 males were making 1,875 feeding 

 marks an equal number of females under the same conditions made 

 2,185 feeding marks and excavated 717 egg chambers. It is thus 

 seen that the opportunity for killing the females by poison sprays 

 applied to the foliage during the egg-laying season is at least as good 

 as for killing the males. 



