CONTENTS 



Page. 



Historical 11 



Losses due to the sugar-beet wireworm 11 



Insects found with the sugar-beet wireworm 12 



Classification, synonymy, and common names 13 



Descriptions 14 



The adult 14 



The egg * 14 



The larva 14 



The pupa 15 



Distribution 16 



Food plants 16 



Life history and habits 18 



The egg 18 



Time and place of deposition 18 



Number and hatching of eggs 19 



Length of egg stage 20 



The larva 20 



Emergence from the egg 20 



The newly hatched larA-a 20 



Rearing cages used 21 



^ Habits of the young wireworms 22 



Approximate length of larval stage 24 



Habits of the older wireworms 25 



Location of food by the wireworms 25 



Activity of the wireworms 26 



Wireworm injury to beets 26 



Time the wireworms can live without food 27 



Relation between injury in the beet fields and the size and al)undance 



of wireworms 29 



Molting of the wireworms 29 



The pupa 30 



Pupation 30 



The pupal cell 30 



Soil conditions affecting pupation 30 



Vitality of the pupa 31 



Changes in color of the pupa 31 



Length of the pupal stage 31 



The adult 32 



Emergence of the adult 32 



Period of emergence 32 



Actions directly after emergence 32 



Appearance of beetles in the spring 33 



Beginning of the period of acti\T.ty 33 



Variation in the size of lieetles 34 



7 



