L26 (lYl'SY AND I'.ROW N-TAIL MOTHS. [Jan. 



of several species. These webs were placed in ti.uht breeding 1 boxes, 

 lilted with -lass tubes, and early in the spring began to yield parasites. 

 The issuing of tlie parasites continued over a period of several weeks, 

 and all told li-1.001) primary parasites were so obtained, of which live 

 plantings of 10,000 parasites each, or 50,000 all told, were made in the 

 field. We also imported 37,7L!!> uypsy moth caterpillars and pnpre from 

 which 1,538 primary parasites were obtained. From 36,191 imported 

 brown-tail moth caterpillars and pupa) 1,104 parasites were obtained. 

 Of the primary parasites of these two species of caterpillars, in round 

 numbers L',000 Tachinid flies were obtained and liberated in the field 

 in L'l different localities. Of the two species of predaceous beetles, 690 

 living Calosoma xi/nij/lnnitit were received, of which 360 were liberated 

 in 7 colonies in the field. Of the smaller species, Calosoma inquisitor, 

 \1'1 were received, of which 110 were liberated in 3 colonies. 



In all this work check experiments were earned on both in jars and 

 caires in the laboratory, where the insects were studied at close ran ire, 

 and also in control cages in the field. These cages were made by throw- 

 ing a light scantling frame over infested trees, covering the frame 

 tightly with cheese cloth and roofing it with heavy duck. All cages 

 used in the experiments both in the laboratory and out of doors were 

 very carefully prepared by Mr. H. R. Gooch, an inspector in the employ 

 of the central office. By means of the field cages we were able to qnite 

 closely follow the breeding habits of the insects, and to determine that 

 certain of the most common small hymenopterous parasites, while 

 breeding principally upon the brown-tail moth, also attacked the gypsy 

 moth. We are engaged at the present writing in collecting in the field 

 in places where these small parasites were liberated a large number of 

 brown-tail moth webs, to determine if the parasites are hibernating, 

 as is their custom in Europe. The predaceous beetles were liberated 

 in places where, by reason of thinning operations or brush fires in recent 

 ye.-irs. there was hut Hi tie danger of further woodland fires, and we 

 have reason to believe that these insects have now become established 

 with us. All plantings of parasites or predaceous insects were made in 

 important woodland colonies of the moths. -- colonies so remote from 

 mads as to make il practically certain that their present condition will 

 not In- disturbed for some years. 



While no one with less than omniscience can tell what the outcome of 

 our labors along these lines may be, the conviction ".rows upon me that 

 we are on the riidit track, that we are doing this work in the ri.u'ht way. 

 and that in the end we shall receive a notable amount of help from 

 these importations. We can now say that to date the parasites have 

 bred here on American irypsy and brown-tail moths in a perfectly 

 normal manner, and are doubtless hibernating in the same way as in 

 Kin-ope. Mo\v well they will stand our New England winters, next 

 Season alone can show; but there seems to lie no good reason to doubt 

 the ultimate success of this experiment, so far as establishing the in- 



