INSECTS AFFECTING FOREST TREES. 49/ 



WHITE PINE WEEVIL. 



Pissodcs strohi Peck. 



This is an exceedingly common insect on hard and white pines in certain years 

 and its operations may be observed to a greater or less extent in almost any group 

 of pines in New York State. The greatest injury caused by this weevil is due to its 

 operations in the terminal shoots of the pines. The beetles may be found in large 

 numbers on the young growth where they apparently feed and deposit eggs in the 

 crevices of the bark. The young grubs work in the inner bark and attack the outer 

 sap wood so that badly infested twigs have these vital tissues entirely destroyed. 

 The insect appears to begin operations in the rough bark just beneath the upper, 

 most whorl and from this point the destruction is continued down the leader to 

 the next whorl and even below it. The larvae make longitudinal, slightly tortuous 

 mines in the inner bark. Their progress is plainly shown b)' the shrunken, dis- 

 colored bark over the affected portion, plate 13, figure 5. The killing of the central 

 shoot is a serious matter in the case of the pine because the tree is compelled to 

 branch and this renders impossible the growth of the long, straight trunks which 

 produce the most valuable timber. This species was collected by the writer in 

 large numbers at Karner, N. Y., and adults were captured in greater or less abund- 

 ance throughout the season, the beetles being most numerous between the 13th and 

 26th of June, and from the 9th to the latter part of August. Earlier writers have 

 stated that the weevils are most abundant the latter part of April or May but our 

 own observations indicate that this species breeds more or less throughout the entire 

 year, and that not infrequently large numbers may complete their transformations 

 in midsummer or the latter part of August. The life history of this species has not 

 been closely followed, and the extended breeding season renders it somewhat diffi- 

 cult to make precise statements. Dr. Fitch was of the opinion that the species com- 

 pletes its life cycle within a )'ear, and it seems very probable that such is the case, 

 and possibl)- it may be completed in a shorter period. The insect is probably able 

 to pass the winter in the larval, pupal and adult stages, the final transformations 

 taking place in small oval cells, about '4 of an inch in length, in the wood ox bark, 

 plate 13, figures 3, 6. The insect also breeds under the bark of pine logs and 

 stumps. The work of this species in such locations is much less serious than that in 

 the twigs, and has attracted verv little attention in the past. 



Dcscri/itioii. The adult insect is a reddish-brown beetle a.bout '^ of an inch in 

 length, and with a whitish spot near the posterior third of each wing cover. The 

 weevil is somewhat mottled on the sides and legs. The snout is rather long and 

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