ENTOMOLOGICAL SOCIETY OF ONTARIO. 73 



prinjary attack, and its principal aids in continuing the devastations, methods of checking 

 the increase of the destructive kinds and protecting forests of healthy timber from their 

 invasions were considered. 



I was convinced from the first that no artificial remedy, such as cutting and burning 

 the infested trees, the removal of the bark from the trunks, etc., could Ibe successfully 

 applied in our West Virginia forests. Therefore, my attention was turned toward the 

 study of the parasitic and predaceous enemies of Scolytids, with a view of ascertaining 

 the most desirable kinds with which to conduct experiments in utilizing them as a means 

 of checking the increase of the destructive species. 



An enemy of Scolytids was desired which would not have to depend on one or two 

 species for its existence, but could readily adapt itself to different species and to varying 

 conditions. 



I found that while Scolytid bark beetles have numerous parasitic Chalcid, and 

 Braconid enemies, few, if any of them, in my opinion, can be relied upon as introduced 

 enemies to suppress or prevent an invasion of these beetles. I found, however, among 

 their predaceous enemies, that the habits of certain species of the Coleopterous family 

 Cleridfe were such, if these beetles occurred, or could be introduced in sufficient numbers 

 in the infested forests, this would certainly have the desired eff"ect. 



In my search for literature regarding native and European Clerids, I found, in a 

 report upon forestry, by F. B. Hough, 1882 (p. 264) as copied from a special publication 

 of the French Foresti-y Adminisfcra, in connection with the Universal Exposition at Paris, 

 that a European species, Tillus formicarius, was mentioned as being a " foe of Bostrickus 

 typographus that pursued them without mercy," during an invasion of these bark beetles 

 in the forest of Abies excelsa in the Jura mountains, from 1SG8 to 1872. This led me to 

 make further inquiries in regard to this and other European enemies of Scolytids, and on 

 October 13, 1891, I wrote to my correspondent;, Oberfoerster W. Eichhoff", of Strasburg, 

 Germany, asking him to send me some pinned specimens of insects known to be special 

 enemies of European Scolytids. At the same time I indicated to him my desire to 

 introduce live examples of such species as in his judgment would prove beneficial in this 

 country as natural enemies of Scolyius rugulosics, Pohjgraphus ru/ipennis, Dendroctonus 

 terebrans, and Dendroctonus frontalis. Among the thirty one species of pinned specimens 

 received from him on November 1 2, he mentioned Clerus formicarius as being " beyond a 

 doubt the best de.stroyer of Scolytids." 



On May 30, 1892, I again wrote to Mr. Eichhoff, mentioning the damage to our 

 forests by DendroGtonus frontalis, and stated that I was very anxious to try the experi- 

 ment of introducing Clerus fonnicarins into our fore.sts as an enemy of this and other 

 bark beetles. In his reply of June 26, he referred me to Director C. Schaufuss, of the 

 museum at Meissen, Saxony, as one who could give me efficient aid in this matter. Upon 

 further investigations of the ravages of the bark beetles in our forests, I prepared a 

 special report, dated July 9, which was addressed to the principal owners of the spruce 

 and white pine timber in West Virginia. In the closing paragraph of this report, 

 reference was made to the successful introduction of the Vedalia into California, and the 

 possibility of introducing in a like manner insects from Europe which would feed upon 

 the destructive bark beetle. It was suggested that it might be necessary to make a special 

 trip to France and Germany for this purpose, and that if the timber interests of the State 

 would share in the expenses of such a venture, this object might be speedily accomplished. 

 In reply to this communication six of the principal timber companies of the State 

 responded with liberal contributions, and I was authorized to proceed at once to Europe for 

 the purpose of studying the insect enemies of European Scolytids, and to collect and 

 import to this country such species as in my judgment would prove efficient in checking 

 the ravages of insects in our forests. 



In studying the enemies of European Scolytids, I found, as in this country, numerous 

 Hymenopterous and Coleopterous parasitic and predaceous species in company with the 

 Scolytids in the bark of the infested trees, but realizing to the fullest extent the danger 

 of introducing insects into this country which might prove injurious as well as beneficial, 

 I took every precaution in the selection of the species. Out of quite a number of enemies 

 of Scolytids observed and considered, only one, Clerus formicarius, was selected, primarily 



