69 



conclusion is tenable. The fact of their attacking a single tree in over- 

 whelming force is peculiar, but apparently not inconsistent with the 

 habits of the other species. In a large portion of the territory explored 

 nearly every tree was affected except the youngest and those partly 

 decayed. The explanation of the immunity of the first probably lies iu 

 the thinness of the bark, which does not offer sufficient protection for 

 so large a beetle. Why the others are not attacked is not so evident. 



As to natural enemies, very few were noticed. One or two species of 

 small Cleridre were observed on the trunks of the dead trees in some 

 numbers, and several species of the larger Braconidre were observed 

 ovipositing there. Some hymen op terous cocoons were found in a burrow 

 believed to belong to this species. Evidence of a fungous disease was 

 also seen. That these insects are sometimes checked by natural means 

 is probable from the fact that the death of the trees has sometimes been 

 attributed to the numbers of little flies that were found under the bark. 



If the destruction of all the spruce that has been reported as dying 

 in northern New Hampshire and the adjoining portions of Vermont, 

 Maine, and Canada is to be attributed to this cause, the injury done is 

 certainly very great. Mr. Cary reports it as working in numerous 

 localities in New Hampshire north of the White Mountains, in north- 

 eastern Vermont, and in Maine as far as the western head waters of the 

 Dead River. It is probable that it extends over a much greater area, 

 but within these limits the damage amounts to many hundreds of 

 thousands of dollars. This region, which is mountainous and thinly 

 settled, is largely covered with virgin forest, and in this the insect does 

 the greatest amount of damage. Compared with the white pine which 

 covers the hills and valleys in the more southern portions of the State, 

 the spruce is of very slow growth, and the ]>roblem of keeping the 

 areas in perpetual forest is a difficult one in any case. It is possible 

 that, as the insect troubles only the older and thicker barked trees, 

 the second growth may be exempt until it is big enough for the har- 

 vest, but this is one of the many points that need looking into. The 

 number of broods a year, the extent of the flight of the female, the 

 probability of natural checks, and the possibility of artificial ones, 

 together with a more thorough knowledge of the conditions necessary 

 to a successful attack, are but a few of the points that remain to be 

 worked out in regard to a most destructive pest of one of New Hamp- 

 shire's best possessions. 



Mr. Hopkins discussed the paper at length, describing the galleries 

 of the species named and allied species, giving some details of the 

 habits of these insects in spruce and pine in West Virginia. He 

 believed Dendroetomis simplex and rufipennis to be distinct species, but 

 could not determine from the notes given by Mr. Fiske which of these 

 species the latter had iu mind. 



