134 Psyche [October 



NOTES ON FOREST INSECTS. 



II. NOTES ON SEVERAL SPECIES OF PITYOPHTHORUS 

 BREEDING IN THE LIMBS AND TWIGS OF \MIITE 

 PINE. 



By M. W. Black-man Ph. D. 



Professor of Forest Entomology, New York State College of For- 

 estry, Syracuse, N.Y. 



Pityophthorus cariniceps LeConte. 



Pityoptlithorus cariniceps LeConte is one of the largest species of 

 the genus Pityophthorus occurring in the eastern section of the 

 country. It is found from Nova Scotia to West Virginia and west- 

 ward as far as Michigan. For many years it has been known that 

 it breeds in spruce (Hopkins,^ 1893, p. 208) and white pine (Chit- 

 tenden,2 1899) but it is still classed by Blatchley & Leng^ 1916 as 

 "quite rare." In the vicinity of Syracuse this species could hardly 

 be classed as rare, although it is not as common as are several other 

 species of scolytids. There is one pine grove about one and one- 

 half miles from the college where the adults or brood can be found 

 at any time during the spring or early summer breeding in the in- 

 ner bark and sapwood of small limbs and twigs which have been 

 storm-broken and have fallen to the ground during the previous 

 winter. * 



On April 24, 1915, adults of P. cariniceps were observed start- 

 ing their burrows in small storm-broken limbs and twigs of white 

 pine in a dense pure stand of trees from 10 inches to 2 feet in diam- 

 eter. The insects were working in limbs from j inch to 1 inch in 

 diameter and in nearly all instances the burrows were started near 

 the axil of a smaller branch where the somewhat rough, folded 

 outer bark furnished foothold for the little workers. Invariably 

 it was the male which started the burrow. In a number of ob- 

 served cases, groups of two or three beetles were found at these 

 new burrows, the males working with part of their bodies in the 

 recently started entrance gallery, while the others, which were 



1 W. Va. Exper. Sta. Bull. 32. 



* U. S. Div. of Forestry Bull. 22. 



' Rhynchophora or Weevils of N. E. America, Indianapolis, 1916. 



