CONTENTS. 



Page. 



Introduction • 9 



History 10 



Origin and distribution 12 



Food plants 13 



Character of injury and destructiveness 14 



Beetles related to the grape root-worm beetle 15 



Beetles frequently mistaken for the grape root- worm beetle 16 



Description 19 



The egg 19 



The larva 19 



The pupa 20 



. The adult or beetle 21 



Seasonal history 22 



The adult or beetle 22 



The process and time of emergence 22 



Variation in the time of emergence 25 



Feeding before and after egg deposition 25 



Mating and its bearing upon egg deposition 28 



Process of egg deposition 28 



Variation in the number of eggs per cluster 29 



Number of separate ovipositions by individual females 29 



Number of eggs deposited by individual female beetles 30 



The oviposition period for the season of 1909 31 



Longevity of male and female beetles 32 



The egg 33 



Incubation period of the egg 33 



The larva 35 



Vitality of the newly hatched larva 35 



Feeding and development of the larva before wintering 35 



Wintering of the larva in an earthen cell 36 



Spring feeding of the larva 37 



Time and making of the pupal cell 37 



The post-larval stage 38 



The pupa 39 



The process of pupation 39 



Position of the pupa in the cell 39 



Time of pupation in the field and in breeding cages 39 



Duration of the pupal period 40 



Life cycle of the grape root- worm as determined by rearing 40 



Seasonal variations in the life history of the grape root-worm 41 



Rearing and experimental methods 44 



Summary of life-history studies of the grape root- worm 50 



5 



