UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 1066 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
S\J^*^J-U 
Washington, D. C. 
June 21, 1922 
CURCULIOS THAT ATTACK THE YOUNG FRUITS 
AND SHOOTS OF WALNUT AND HICKORY. 
By Fred E. Brooks, 
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 (C onotrachelus 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 
that they select different food plants or have different methods of 
attack. 
Several members of this group attack acorns and there are also 
several species of an allied group of snout-beetles* (genus Balaninus) 
the larvae of which feed in mature, or nearly mature, chestnuts, hick- 
ory nuts, hazelnuts, and acorns. These are not dealt with in this 
bulletin. 
88253°— 22 
