:MS GYPSY AND BROAYN-TAIL MOTHS. [Jan. 



for them and the manner in which they are being carried on, I am 

 bound to say that I have little to offer by way of criticism or sug- 

 gestion. The living parasites received are released, as a rule, as quickly 

 as possible after arrival: the larva- and pupa- alive on arrival are kept 

 with ureat can- under the most favorable conditions until they have dis- 

 closed such parasites as they come infested by, and these are released 

 as promptly as consistent with scrupulous care that nothing else is 

 permitted to get away. 



The experimental operations for the infestation of American-bred 

 specimens by the imported parasites and for the multiplication of the 

 latter by that means are being carefully and very wisely carried on. 

 A good deal of practical ingenuity and the results of much practical 

 experience are shown in the various devices used in breeding-cage opera- 

 tions and in the assoi'tment of living material. I believe that the whole 

 .ceclurc is thoroughly sound, and that the work is being most care- 

 fully and intelligently done. 



It appears that there is a considerable loss of parasitic material, par- 

 ticularly of that emerging from the hibernating webs of the brown- 

 tail moth brought over in winter, owing to the difficulty of getting the 

 parasites separated fioin their hosts in the storage boxes used for that 

 purpose. Mr. Fiske described to me, however, a proposed improve- 

 ment of your present apparatus, which it seems to me will go far 

 towards remedying this difficulty. 



I was much interested by the evidences of extensive fatal fungous 

 diseases among the caterpillars arriving from Europe, and I understand 

 that these diseases are undergoing expert study, at least as to their 

 causes. If I were to make any suggestion of change or development 

 in your methods, it would be that you should have investigated, in 

 every practicable way and as rapidly as possible, by men wholly under 

 your control, the fungous diseases of these insects, with a view to their 

 experimental increase and their spread in the field. 



The muscardine of the brown-tail moth, according to statements 

 made to me by your men, has done more to diminish the numbers and 

 arrest the progress of that insect than any other agency, seems likely, 

 indeed, to reduce the pest to insi-nilicancc; and the gypsy caterpillars 

 are also subject to serious disease, apparently of a bacterial character. 



The muscanlines. dependent on spores formed in tl pen air for their 



spread, are more susceptible to \veatlier conditions than the bacterial 

 diseases, and are hence less reliable than the latter as a means to the 

 economic end: but both these forms seem to me to be well worthy of 

 thorough investigation and experimental trial. 



I have to thank your commission for the opportunity to examine n 

 -ituation so extremely interest in- to an entomologist, and should In- 

 pleased if I mi^ht have found myself able to make suggestions of 

 jivater value in aid of your work.- important not only to your 

 and to Ne\v Kii'jland, but to (lie entire country as well. 



