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assistance throu^ some of the clerks of the Division of Entomology at 

 odd moments. I have now accumulated about 20,000 cards, each one re- 

 ferring to a recorded rearing of a hymenopterous parasite in Europe^ 

 I am now engaged upon the work of arranging these cards according 

 to the latest accepted classification of the host insects, and it proves a 

 task of equal magnitude to the original preparation of the cards, but 

 already I can see unsuspected generalizations ahead, and already I feel 

 myself much better acquainted with group habits. I have been able to 

 draw up a short table of the American and European parasites of in. 

 sects common to both continents, and in the case of several recently 

 imported pests have been able to tabulate at once and without search of 

 the literature lists of the European parasites, thus indicating the best 

 species for importation, and also showing which of our own forms will 

 be most likely to attack the newcomer. 



When it comes to the host relations of our own parasites, however — 

 and this, for our purposes, as constant students of insects in the breed- 

 ing cage, is by far the most important side of the work — the poor show- 

 ing which we make is most deplorable. In 1885 I published a short 

 list of about 60 reariugs of Chalcidids, in 1889 a compiled list of less 

 than 100 rearings and in the same year a list of 116 rearings of butter- 

 fly parasites. During the present year the editors of Insect Life have 

 been publishing the rearings of Hymenopterous parasites indicated in 

 the notes and collections of the Division of Entomology and National 

 Museum, largely from Professor Eiley's earlier notes, and have recorded 

 some 300 rearings of Braconidse and have ready for publication about 

 300 of the family Ichneumonidae. Lists of rearings in the Ohalcididse 

 Proctotrupidse and in the parasitic Cynipidse which will follow will be 

 much shorter, not from lack of material, but from the incompleteness 

 with which the collections in these families are determined. 



As to the scattered records, in the reports of economic entomologists 

 and in our entomological journals, most of you would probably be sur- 

 prised, as I have been, at the extremely small size of a list based upon 

 such records. It will certainly not equal in size the short combined 

 lists already published, so that altogether from published records we 

 shall have a total of less than 1,500 American rearings. This as against 

 20,000, which I estimate for European records, is such an unfavorable 

 contrast that I am anxious to improve it greatly before publishing, and 

 I am satisfied that this can be done by enlisting the active cooperation 

 of the members of this association. 



What I would urge you to do is this : (1) prepare and publish lists of 

 your rearings of such parasites as you have named in your collections } 

 (2) if you have neither the time nor the facilities for naming the un- 

 named species send them to Professor Eiley at Washington, and I have 

 his authority for the promise that he will name them or have them 

 named by comparison with the National collection. (In such case send 

 duplicates, when possible, which need not be returned ; but if necessary 



