700 BULLETIN UNI'lED STATES GEOLOGICAL SURVEY. 



The larva is found in the Middle States, New York and Pennsylvania, 

 in June and July, beneath the bark of the Eed Pine and the White 

 Pine {Pinus resmosa and P. strobus); also on the Scotch, Eussian, and 

 Austrian imported pines. The wounds occur on the main stem, usually 

 below the insertion of the branch. On cutting into tlie bark beneath 

 the exuding pitch, the larva may be found, which measures about 18 

 millimetres when full-grown. The head is shining chestnut-brown, with 

 black mandibles. The body is livid or blackisb-green, naked, with series 

 of black dots, each giving rise to a single bristle. The prothoracic shield 

 is blackish. The larva has three pair of thoracic or true jointed feet and 

 four abdominal or false feet, besides anal claspers. This larva, eating on 

 the inner side of the bark, and making furrows in the wood, causes the 

 bleeding, which, when the depletion is excessive or continuous, and espe- 

 cially in the case of young trees, has proved fatal. In July, the worm 

 spins a whitish, thin, papery cocoon in the mass of exuded pitch, which 

 seems to act as a protection to both the larva and chrysalis. The ;pupa 

 is cylindrical, smooth, narrow, blackish-brown, about 16 millimetres in 

 length. The head is pointed, there being a pronounced clypeal protube- 

 rance ; the segments are unarmed ; the anal plate is provided with a row 

 of four spines, and two others, more slender, on either side of the mesial 

 line, below the first. It gives the moth in ten to fourteen days. 



Finipestis Zimmermani seems to be one of the most destructive of 

 Lepidopterous insects to timber. I have seen a number of young pine- 

 trees killed by it. It is an American form, and differs structurally from 

 the European Dioryctria abietella by the peculiarities of the male antennae 

 and the different position of veins 6 and 7 with regard to the cross-vein 

 on primaries. 



It is not certain how the hibernation of P. Zimmermani is accom- 

 plished. From the fact that Mr. Zimmerman has found larva resembling 

 those of this species in the clots formed by the exuding pitch in Jan- 

 uary, it may be that the species winters in the larval state, and that it 

 is single-brooded. The identification of these winter larvse is not com- 

 plete. In color they were more pinkish than the specimens taken in 

 June, and (but this might be expected) smaller in size. Again, whether 

 the larva feeds on the gum or not is uncertain, though certain of the 

 facts observed point to this conclusion. 



For an opportunity of examing specimens of Dioryctria abietella, I am 

 indebted to Mr. Charles U. Zimmerman. The joints of the antennj© 

 are distinct, so as to give a serrated appearance to these organs. The 

 European species is much smaller and less brightly colored than Zim- 

 merman's Pine Pest, and wants notably the patches of raised scales on 

 the wings, on which I have dwelt in my original description, and which 

 are so distinctive of Zimmermani. There cannot remain the faintest 

 doubt of the distinctness of Zimmerman's Pine Pest from the European 

 abietella. The probable difference in the clypeal structure of the pupa 

 .and the differing habit of the larva of Zimmermani, as compared with 



