MONTANA EXPERIMENT STATION. 



225 



Like other members of the same family of beetles (Biiprestidae) 

 the adults are diurnal in habits and are most active during the heat 

 of the day. By a close search in an infested orchard during the sea- 

 son of the year wheii the adults are out, one may find them basking in 

 the sun on the trunks of the trees and on prostrate logs. 



DISTRIBUTION AND OCCURRENCE IN MONTANA 



The flat-headed apple-tree borer is a native of North America 

 insect. In spite of this fact, however, we believe that it is an in- 

 troduced species in Montana. None of its principal food plants, so 

 far as known, are native to the state, or if present, occur only spar- 

 ingly, and moreover, its presence has been detected only in restrict- 

 ed localities. We think it much more probable that the insect was 

 brought into the state on some of the earliest shipments of trees 

 from the older apple growing regions. 



It is a widely distributed pest throughout the United States 

 east of the Rocky I\Iountains, and in southern Canada. 



Figure 9. Flat-headed Apple-tree Borer, 

 a, larva; b, beetle; c, head of male; d, pupa 

 — twice natural size. (Chittenden, Circular 

 32, Sec, Series, Div, of Entomology U. S. 

 Dept. of Agr.) 



LIFE HISTORY. 



The eggs, which are pale brown and about one-eighth of an inch 

 long, are laid on the trees during the hot summer months. One ob- 

 server. Dr. Riley, found them being laid from June to September, 

 but our observations in Montana indicate that while a few beetles 

 may be found on the trees later in the season the majority are out and 



