JOIMAL OF AGRICULTURAL RESEARCH 



DEPARTMENT OF AGRICULTURE 

 Vol. Ill Washington, D. C, January 15, 1915 No. 4 



OBSERVATIONS ON THE LIFE HISTORY OF AGRILUS 



BILINEATUS 



By RoY.'U, N. Chapman, 



Graduate Assistant, Division of Entomology, Department of Agriculture, 



University of Minnesota 



INTRODUCTION 



At the present time the two-hned chestnut borer, Agrilus bilincatus 

 Weber, is commonly associated with the death of many oaks {Quercus spp.) 

 in the southeastern part of Minnesota. In 1885 reports called attention 

 to the damage done by this insect on oaks in Massachusetts, and since 

 that time they have been frequently mentioned as enemies of the chestnut 

 (Castanea dcntaid) and oak. It was not until 1 897 that F. H. Chittenden * 

 described the adult, the larva, and the pupa, in connection with a brief 

 summary of its life history, so far as it was known at that time. In this 

 article it was stated that the adults appeared in the District of Columbia 

 from May to the middle of June and laid their eggs on trees and that 

 the larvae worked under the bark across the grain of the wood, making 

 a burrow from 6 to 10 inches in length, and by the next spring had 

 constructed a chamber in the bark of living trees, where the pupal stage 

 of about two weeks was passed. Although the name of this beetle has 

 been common in current entomological literature, nothing of note has been 

 added to the knowledge of its life history since Chittenden's article. 



During recent years in the neighborhood of St. Paul and MinneapoUs 

 great numbers of oaks, many of them on valuable residence property, 

 have been killed, and their death has commonly been attributed to this 

 pest. In some of the outlying country districts areas of several acres in 

 extent have been completeh' devastated, leaving the land treeless. 



The present work was begun at the University of Minnesota during 

 the fall of 1 91 3 at the suggestion of Prof. O. W. Oestlund, of the Depart- 

 ment of Animal Biology, under whose direction the problem was out- 

 lined and the work on the larval and pupal stages begun. In the spring 

 of 1914 the work was continued at the Minnesota Agricultural Experi- 



1 Chittenden. F. H. Insect injury to chestnut and pine trees in Virginia and neighboring States. In 

 U. S. Dept. Agr., Div. Entom. Bui. 7. n. s.. p. 67-71. 1897. 



Journal of Agricultural Research, Vol. HI, No. 4 



Dept. of Agriculture, Washington, D. C. Jan. 15, 1915 



Minn. — 3 



