The Curculio. 29 



In the effort to ascertain what our scientific friends have had to say 

 upon this subject, we notice bulletin No. 98, University of Illinois Agri- 

 cultural Experiment Station, "The Curculio and the Apple," by Prof, 

 Charles S. Crandell. Perhaps a few paragraphs from this work may 

 b<» of general interest and may encourage the planter to at once start 

 his disc in motion and during the next thirty days as far as possible 

 destroy the larvae before they emerge as mature beetles 



"The life cycle of the plum curculio is as follows: At about the 

 time in early spring when vegetation resumes activity and buds begin 

 to push, curculios which have hibernated under rubbish on the ground, 

 under the rough bark of trees and in other secure hiding places, emerge 

 from concealment and seek the fruit plants upon which they feed and 

 breed. About the time the trees bloom, mating begins, and as soon as 

 the young fruit enlarges the deposition of eggs begins. Apples no 

 larger than small peas often bear from one to three of the character- 

 istic crescent marks made by this curculio. The deposition of eggs 

 goes on most rapidly during the month of June, but continues through 

 July and August, gradually growing less and less as the beetles die. 

 The majority of the beetles of this generation do not live beyond the 

 month of July, but a few may survive until September, or in rare in- 

 stances until late fall. During the season both males and females feed 

 upon the same fruits in which eggs are deposited, making small, usually 

 cylindrical punctures. The eggs hatch in from four to six days and the 

 young larvae start tortuous burrows through the fruit. The larvae 

 when fully developed average .32 inch in length and .078 inch in 

 thickness. Development of the larvae causes the fruit to fall wtihin a 

 few days. In about twenty days the larvae mature, cease feeding, bore 

 out of the fruit, and at once enter the ground where they complete 

 their transformation and in about twenty-eight days emerge as perfect 

 beetles. The newly emerged beetles usually remain quiet for a day or 

 two, allowing the body wall, beak and jaws to harden; then they fly 

 Into the trees and begin feeding upon the fruit. Beetles of this new 

 generation do not (except possibly in rare cases) pair, and no eggs are 

 laid during this first season. The fruit is freely punctured for feeding 

 purposes and the amount of this work increases as the season advances. 

 It is this feeding of the new generation that causes the greatest injury 

 to the fruit crop. Feeding continues as long as fruit remains on the 

 trees. Late in the fall the beetles leave the trees and hide away in 

 secure places for the long winter period of hibernation." 



"No case has been found of the full development of a plum cur- 

 culio larvae in fruit remaining upon the trees. It seems to be neces- 

 sary to larvae development that the fruit fall. Sometimes the larvae 

 complete development before the decay of the fruit begins; more fre- 



