24 N. H. AGRI. EXPERIMENT STATION [Bulletin 247 



the trunk and roots of a dead white pine located in the Dover Road 

 plot. Mature larvae and pupse, and predacious Lonchea larvae, were 

 found in the same tree. In 1928, one pupa taken from the roots of a dy- 

 ing white pine transformed July 12. 



P. approximatus was first described in 1911 by Dr. A. D. Hopkins in 

 his monograph of the genus Pissodes. Since that time little has been 

 written concerning it. Felt (1926) reports this species in company with 

 Hylobius pales, Hbst., attacking Scotch pine. Britton (1919) mentions 

 it as attacking red pine and stone pine. 



Hopkins (1911) says P. approxi?natus can be distinguished from P. stro- 

 bi by the average larger size and elongate body. The sides of the elytra, 

 are more narrowed posteriorly. He figures the stems and forks of the 

 male genitalia. It has been impossible to determine this species by the 

 kej' given by Hopkins. 



A number of experiments were made to determine if the white pine 

 weevil is able to breed on the trunk and roots of white pine. Several 

 P. strobi adults were confined to the trunk of a five foot tree by means 

 of a cylindrical glass tube. Later the tree was dug up and placed in a 

 pail in the laboratory. Three larvae pupated in the trunk on July 12 

 and emerged July 25, 1927. 



Wire cages, each containing four pairs of white pine weevils, were fast- 

 ened to the trunks of several trees near the base. Much feeding was 

 evidenced by the exudation of pitch. Repeated experiments for two 

 years failed to show breeding in this part of the tree. 



The white pine weevil evidently can breed in the trunk of a weakened 

 tree, such as the one brouglit into the laboratory. 



It is possible that adults passing up the trunk after leaving hibernation 

 may lay eggs in the lower part of the tree. If eggs are laid, they may 

 hatch and produce larvae which might survive in a weakened tree. 



It may be significant that the type specimen of P. approximalus was 

 reared from a larva in the bark at the base of a white pine tree defoli- 

 ated bj' the gipsj' moth {Portheiria dispar L.) and tlierefore presumably 

 weakened. 



Our data raise the question whether P. approximalus may not be iden- 

 tical with P. strobi, though further observations would be necessary for 

 a definite statement. 



CONTROL 



No methods of complete control have been developed, although sever- 

 al satisfactory^ measures for materially reducing infestation are applicable 

 in ornamental or commercial plantations of white pine. Manifestly, it 

 may be economically impossible to apply some of the methods used for 

 controlling the weevil in ornamental plantings to plantations grown for 

 timber purposes. 



Control methods can be divided into two groups, direct and indirect. 

 Included in the first group are chemical measures such as sprays, washes 

 and repellents. Direct mechanical measures include, also, the collection 



