364 WEST VIRGINIA EXPERIMENT STATION. 



shops, newly painted houses, etc. They were reported as coming- like a 

 hail storm against the windows and into houses through the ope'n doors 

 like swarms of bees, and that the air on all sides was full of them. Dur- 

 ing my absence from Morgantown (where our Station is located) one of 

 these migrating swarms of Scolytids invaded the town and occurred at 

 certain houses and at furniture factories in such immense numbers that 

 some of the people became alarmed. The report was started that Hop- 

 kins's German bugs had devoured all of the pine bugs and were going to 

 prove a universal pest like the English Sparrow. It was probably well for 

 me that I was absent at the time. 



The men were painting a new green house at the time, and the number 

 of the beetles attracted to the building evidently by the odor of turpen- 

 tine, were so great that the men were exceedingly annoyed in their work. 

 When I returned to the Station several days after, I found evidence of 

 their numbers in the handsful of dead beetles that failed to escape from 

 the greenhouse. 



Dendroctonus terebrans occurred in by far the greatest numbers in these 

 migrating swarms, and when they failed to find dying or injured trees 

 they attacked living pine of all kinds, black spruce and Norway spruce, en- 

 tering the bark at the base of the trees. Some of the trees thus attacked 

 in May were examined July 15, and the bark near the base was found to 

 contain parent adults, eggs, and grown larvae, the larvae occurring in 

 great numbers surrounded by the flowing turpentine. Trees thus infested 

 were still living but the injury will probably cause a diseased condition 

 of the trees, which will attract other species and result in their final 

 death, thus we may be on the eve of a new destructive invasion like that 

 which has just passed. Other species, like Polygraphus ruftpennis in the 

 spruce, Tomicus calliqraphus and Tomicus cacographus, in pine, which are 

 capable of existing in green, sappy bark, occurred in such abundance in 

 the dying trees last spring that it is evident they must exist in the forests 

 in great numbers, and are ready to attack trees showing the slightest indi- 

 cation of disease or weakened vitality, if they do not make a primary at- 

 tack. 



Therefore, the imported enemy will find abundant food and favorable 

 conditions for its rapid increase in the infested bark of felled trees, tops, 

 and stumps in lumbering regions in or near which the colonies have 

 been placed. 



The imported Clerid does not confine itself to one or two species of bark 

 beetles in one kind of trees but the adults, it would seem, will attack and 

 devour the adults of any species of bark and timber beetles found in the 

 United States, and their larva will feed on the eggs, larvae, pupae, and 

 young beetles of any species infesting the bark of pine and spruce trees. 

 In fact, they are inclined to make themselves generally obnoxious to the 

 little bark pests. 



It would appear that all of the conditions necessary for the imported 

 Clerid to multiply and become an efficient protector of our pine forests 

 from future destructive invasions of bark beetles are most favorable. 

 Dendroctonus frontal is, evidently the most destructive enemy of our pine 

 forests, has, from some cause, been reduced far bej^ond its destructive 

 powers. Other species which have depended upon it for the primary at- 

 tack are, it would appear, somewhat demoralized on account of the dis- 

 appearance of their benefactor. The large amount of felled timber found 

 in the several lumbering regions will probably attract the larger portion of 

 other threatening bark beetles away from the green trees, and by the 

 time Dendroctonus frontalis can again marshal sufficient forces to success- 

 fully attack and kill the trees, they will, it is hoped, be met with a force of 

 enemies led by the European bark beetle destroyer, which will succesfully 



