320 WEST VIRGINIA EXPERIMENT STATION. 



among themselves. There is a large number of predaceous insects in all 

 the orders, which like highway robbers, attack other individuals. On ac- 

 count of the particular taste of the enemy they seize only certain kinds of 

 food. Therefore, wherever nourishment occurs for insects their enemies 

 are also associated with them, and finally malicious sneakers, the internal 

 parasites, which are found in great abundance in the Hymenoptera and 

 Diptera, prey upon their hosts. * * * * 



* * * In July of this year Mr. Andrew D. Hopkins, of the W. Va. 

 Agr. Exp't Station at Morgantown, communicated to the readers of 

 Science, Vol. XX,l how in late years the bark beetle, Dendroctonus front- 

 alis, Zimm, has appeared in such vast numbers in West Virginia that upon 

 a territory of 10,000 sq. miles 75% of all pine trees have been either injured 

 or killed outright. * * * Therefore. Mr Hopkins has conceived the 

 idea, that after he had observed how Clerus dubius. F. gave trouble to 

 the Scolytids by thinning their ranks, to place with it Clerus formicm-i/tv. 

 L. to help in its good work in order, at least, to do what is possible to over- 

 come the enemy of the forest. 



Europe and North America have had for a long time an active com- 

 merce between both sections of country and through the similarity of 

 climate there has been a reciprocal exchange of injurious insects. I am 

 reminded of the introduction of the potato beetle (Leptinotarsa decimlineata, 

 Say) into Germany, and the cabbage butterfly (Pieris brassicae [ropae.] L.) 

 into the United States. Why not also introduce beneficial insects? 



Mr. A. D. Hopkins did very well indeed to direct his attention to Eu- 

 rope. And as a fact we have in Cterus formicarius a beetle that not only 

 closely resembles in its appearance, size and color its American brother, 

 Clerus dubius, F., but also similar to the latter in its mode of living. It is, 

 as a larva, as well as adult, a keen enemy of the coniferous bark beetles. 

 No matter whether the bark beetles live upon the pine or fir, the Clerid 

 occurs in considerable numbers. For this reason Mr. Hopkins chose it 

 [C. formicarius] for importation to America. 



In order to carry out his plan he pleased himself in communication with 

 the eminent Scolytid specialist, Eichhoff and myself, and in August 

 came to Europe to study the life history of the insects and collect them. 



Mr. Eichhoff wrote to me while Mr. Hopkins was collecting in Alsace 

 that he [Hopkins] worked "with extraordinary skill and great success," 

 and I can corroborate his particular view, as I was for many 

 days in company with Mr. Hopkins in the Saxon forest searching for 

 Clerids. We found the larvae, the pupae, even the emerging images in 

 their artistic winter quarters within the bark. 



Thus, Mr. Hopkins can look with satisfaction upon the result of his 

 journey for he took a large number of Clerids in all the localities visited, 

 and for safety in transportation one half was packed in one way and the 

 other half in another. And at that time probably but a-few would succumb, 

 since by far the greater number had arrived at their winter rest. If on 

 account of the exaggerated cholera scare, the quarantine does not destroy 

 Mr. Hopkins' treasures the experiment of acclimatization can be com- 

 menced in the spring. A sufficient additional batch will be provided 

 by me to enable Mr. Hopkins' experiment to succeed." 



FIRST IMPORTED CLERIDS LIBERATED IN AMERICA. 



After my return to Morgantown on Oct. 7th, the subject of 

 the distribution and colonization of the examples I had brought 

 over with me was duly considered, and it was decided that 



1 Quoted on another page. 



