LARV^ OF THE PRIONIN^. 19 



radially striate area with deep pore, xlbdominal spiracles broadly 

 oval. Form tapering gradually to anal segments, anal lobes with 

 two to four stiff hairs, about equal in size; texture firm, shining. 



All specimens of this species examined have been collected from 

 the living: roots of oak and chestnut. It occurs throughout the east- 

 em and central United States. The adults fly through June, July, 

 and August. Dr. Hopkins finds it especially destructive to chestnut 

 in West Virginia, causing death of the tops and branches. Adults 

 fly from June to September. The femal.es lay from 100 to 200 eggs, 

 deposited in groups about the base of trees. The young larvae feed 

 in the bark before penetrating into the heartwood of the roots; later 

 they completely hollow them. The larval stage extends over a 

 period of at least three years. Larvae hatched from eggs after one 

 year were rarely over 2 centimeters in length. Several adults reared 

 during July, 1914, of both P. imhricornis and P. pocularis showed a 

 pecuhar habit in pupating. (PL VIII, fig. 1.) The larvae left the 

 roots in wliich they were boring, came to within 4 inches of the surface, 

 and there made a large oval pupal cell about 7 by 4.5 centimeters in 

 size, consisting of earth and sand held together by a secretion of the 

 larvae. The inside dimensions were just large enough to contain the 

 pupa. The inner walls were very smooth and lined with a secretion. 

 The adult emerged through the ground. 



Since these observations were recorded the ^^o-iter's attention has 



been called to a note by Riley ^ in which similar pupation habits are 



recorded. 



Prionus laticollis Drury. 



Epistoma projecting in a dull dentate carina, heavier than in imhri- 

 cornis; front produced in a straight transverse carina (less extended 

 than in imhricornis), divided in middle; mandibles short, outer face 

 strongly rugose, cutting edge obliquely truncate, upper inner angle 

 bearing a short, obtuse, nonstriate tooth. Labrum transversely ob- 

 long, twice as wide as long, sparsely haired behind anterior margin; 

 antennae as in imhricornis. Palpi conical, last joint of maxillary palpi 

 conical, not longer than second is wide; hairs on lacinia and ligula 

 not dense, integument distinctly seen between them. Ocelli ab- 

 sent. Postcondylar carina faint; subfossal spine acute conical. 



Body as in imhricornis, except that the legs are less hairy and the 

 last joint (not spine) is much longer than the penultimate. 



This species has been recorded attacking a large variety of hard- 

 woods, causing serious damage to the roots of living trees, chiefly 

 oak, poplar, and chestnut. Throughout Virginia and some of the 

 Southern States serious injury and often malformation of the tree 

 have been recorded as caused by this insect. 



1 Riley, C. V. Notes of the year. In U. S. Dept. Agr., Div. Ent., Bui. 12, old ser., p. 32-45, 1SS6. The 

 tile-homed Prionus in prairie land, p. 39. 



