26 



86. The Parmacheene Bark-Beetle (Xyloehinus n. sp.). 



Excavates short, irregular egg galleries in the dead bark of small red spruce and 

 balsam fir. Islands of Parmacheene Lake, Maine. 

 Exhibit: Work. 



87. The Red Spruce Scolytus (Scolytus n. sp.). 



Excavates two longitudinal egg galleries from a central entrance burrow and small 

 lateral cavity in the living bark of branches of dying and recently felled red spruce. 

 Northwestern Maine and Peak's Island, near Portland, Me. 



Exhibit: Adult and work. 



CASE 33. 



88. The Minute Spruce Bark-Beetle (Crypturgus atomus Lee). 



Enters the galleries of other bark-beetles, from which it excavates numerous very 

 small, irregular galleries through the inner bark of dying and dead black and red 

 spruce and white pine. Northwestern Maine. 



Exhibit: Adult and work. 



89. The Spruce-Destroying- Beetle ( Dendrodonus piceaperda Hopk.). 

 Excavates long, longitudinal egg galleries from a basal entrance burrow in the 



bark, and grooving the wood of living and injured red and white spruce trees. Very 

 destructive to the largest and best timber. Northern Maine to New York and New 

 Brunswick. This is the great enemy of the red and white spruce of the northeastern 

 spruce region, having caused the death and loss of a vast amount of timber. For 

 methods of preventing losses, see Bulletin 28, n. s., Division of Entomology, U. S. 

 Department of Agriculture. 

 Exhibit: Adult and work. 



ENEMIES OF BARK-BEETLES. BIRDS AND INSECTS. 



PART OW CASE 33. 



90. Work of woodpeckers in spruce bark, when infested with the spruce- 



destroying" beetle. 

 These birds are exceedingly beneficial in destroying the greatest enemy of the 

 spruce. 



Exhibit: Work. 



91. The Cloudy Bark-Beetle Destroyer (Thanasimus nubilus Kl.). 



The adults feed on the adults of the spruce-destroying and other bark-beetles, 

 and its young or larvae prey upon their developing broods. Very beneficial. The 

 specimen of bark shows the pupa case of the Clerid in an egg gallery of the spruce- 

 destroying beetle. 



Exhibit: Adult and work. 



92. Polyporus volvatus Peck. 



A fungus growing from entrance and exit burrows of the spruce-destroying beetle 

 in the bark, and the spruce-timber beetle in the wood, and from those of other bark 

 and wood boring insects in dying and recently dead spruce trees killed by the spruce- 

 destroying beetle in the Northeast, and the fir-destroying scolytus in the Northwest. 

 The presence of this fungus usually indicates the destructive work of insects. 



Exhibit: Work. 



93. Parasitic Enemy of the Spruce-Destroying" Beetle (Bracon simplex Cress). 

 The adult deposits eggs in the bark with the developing brood of the bark-beetle; 



the young maggot-like larvae feed upon and kill the young. Very common and bene- 

 ficial. Maine to West Virginia. Also attacks numerous other bark-infesting insects. 

 The bark specimen shows the cocoon in which the matured larva develops to the 

 adult. 



Exhibit: Adult and work. 



