Page:The white-pine weevil (IA whitepineweevil290hopk).pdf/9

 period of development of the larvæ varies greatly. Those more fortunate in securing a continuous food supply may become fully developed before some of the less fortunate ones in the same terminal are one-fourth as large, although the eggs from which both came may have been deposited at about the same time. There is also a wide range in the period of transformation to the pupa and adults and again in the emergence of the latter. Thus, if the first eggs are deposited about the 8th of May at Milford, Pa., latitude 41° 20′, altitude 500 to 1,000 feet, the first eggs will begin to hatch about the 14th of May, the first larvæ will be full grown about July 8, the first transformations to the pupæ will take place about the 15th of July, the first adults will begin to emerge about July 25, and adults will continue to come out until the first part of September. Practically all will be out by September 15. The principal period of emergence, however, is from about the 25th of July to the middle of August.

The white pine is the tree normally attacked, but the weevil is occasionally found in the terminals or topmost branches of the native and cultivated spruces, the jack pine, and very rarely in the pitch pine or other eastern pines. The attack is confined to the small to large sapling and pole stage in the development of the tree.

Our records indicate that this weevil follows the natural range of the white pine from southwestern North Carolina into New Brunswick and Canada and westward into Wisconsin.

The first evidence of attack on the living terminals is the exudation of fresh, clear, and shining drops of resin. Upon closer examination fresh pinhole-like punctures are found in the bark (fig. 3), and at the same time the inconspicuous beetles may be found on the terminal; but upon the approach of the observer the beetles will often let go their foothold and fall to the ground, where they will feign death. In a few days after the first attack the injured terminals are infested with larvæ is the stunted, unhealthy appearance of the young growth at the tip, which will gradually die, the needles turning yellowish and later brownish.

The time of development of the broods to adults will be indicated by the first appearance of dead tips.

Old work of the weevil is evidenced by the presence of old dead ter-