408 WEST VIRGINIA EXPERIMENT STATION. 



and spruce and also in the cultivated Norway spruce, to all ot 

 which its attack proved fatal. The list is as follows: 



W hite Pine Pinus strolus L. 



Scrub Pine Pinus Virginiana Mill. 



Yellow Pine Pinus eohinata Mill. 



Table Mt. and Hickory Pine . . .Pinus pungens Mich. 



Pitch Pine Pinus rigida Mill. 



Black Spruce Picea mariana (Mill.)B.S.P. 



Red Spruce(?) Picea rubra, (Lamb) Link. 



Norway Spruce . . Picea excelsa, Link. 



It will doubtless attack any species of n-ative or introduced 

 pine and spruce upon which it may happen to settle when it 

 occurs in great swarms as it did in 1892. Hence, this insect 

 may be considered one of the most dangerous enemies of this 

 class of forest and shade trees. 



NATURAL ENEMIES. 



I have discovered a number of natural enemies of this spec- 

 ies; but it appears that none of them are specific enemies of it, 

 since they are all known to attack other species. of bark beetles 

 or other insects which infest the pines or spruces. These 

 which are parasitic on the larva or pupa are as follows: 



PARASITIC ENEMIES. 



jBracon pissodes Ashm Both sexes reared from cocoons 

 found in larval mines and pupa cases of D. frontalis in scrub 

 pine near Dellslow, Monongalia county, November 7th, 1892. 

 This, as the name indicates, is also a parasite of a curculionid 

 of the genus Pissodes. 



Heydenia unica Cook and Davis. 1 Reared from larvae 

 fo'ind in larval mines and pupa cases of D. frontalis in scrub 

 pi ae near Dellslow, West Virginia. This species was also rear- 

 ed by Professors Cook and Davis from larch infested with 

 Polygraphus ruftpennis and Dendroctonus (similis ^simplex. 

 I have also reared it from cocoons found in the larval mines 

 of Pissodes strobi in scrub pine at Ronceverte, Greenbrier 

 county, W. Va. on April 30th, 1893. 



1. Bull. 73. Michigan Agr. Exp. Station, 1891. p. 15, 



