UNITED STATES DEPARTMENT OF AGRICULTURE 



» BULLETIN No. 1066 



?Ml i S^I/ff» Contribution from the Bureau of Entomology •*' 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



s±fr*&mru 



Washington, D. C. 



June 21, 1922 



CURCULIOS THAT ATTACK THE YOUNG FRUITS 

 AND SHOOTS OF WALNUT AND HICKORY. 



By Feed E. Bkooks, 

 Entomologist, Fruit Insect Investigations. 



CONTENTS. 



Page. 



Introduction 1 



The butternut curculio 2 



Distribution 2 



Food plants 2 



Nature and extent of injury 3 



Life history 4 



Natural enemies 7 



The black-walnut curculio 7 



Distribution 8 



Food plants 8 



Nature and extent of injury 8 



Life history 9 



Natural enemies 11 



Page. 



The hickory-nut curculio 11 



History and distribution 12 



Food plants 12 



Life history 12 



Natural enemies 13 



The hickory-shoot curculio 14 



Distribution 14 



Food plants 14 



Life history 14 



Natural enemies 15 



Methods of controlling nut-infesting 



curculios 16 



INTRODUCTION. 



Several species of snout-beetles nearly related to the common plum 

 curculio (Conotrachelus nenuphar Hbst.) attack the immature fruits, 

 tender shoots, and leaf petioles of walnut and hickory. Four such 

 species are discussed herein, all belonging to the genus Conotrachelus 

 and all having evidently at times been confused under the one most 

 Familiar species, Conotrachelus juglandis Lee. The four species 

 throughout the several stages of their development resemble one an- 

 other closely in appearance, habits, and seasonal activities, except 

 th;ii they select different food plants or have different methods of 

 attack. 



Several members of Ibis group attack acoms and I here are also 

 several species of an allied group of snout-beetles (genus BalaninUs) 

 the larvsB of which feed in mature, or nearly mature, chestnuts, hick- 

 ory nuts, hazelnuts, and acorns. These are not dealt with m this 

 bullel in. 



268 22 



