220 GYPSY AND BROWN-TAIL MOTHS. [Jan. 



ment, because the spread of the insect has been so great and is so easily 

 accomplished. Extermination of the gypsy rnoth is almost as difficult 

 to attain, and under the conditions would prove so very costly as to 

 put it practically beyond reach. Control only is the aim of the present 

 organization, and that this is possible it has proved to demonstration. 

 But the cost has been enormous, and with present methods there seems 

 to be no period to the expenditure. Under these circumstances all 

 natural aids should be pressed into our service, and the line of study 

 and investigation which I deemed inadvisable ten years ago is now 

 essential. The work of securing parasites and other natural enemies is 

 well under way, has been carried on for two full seasons, and after 

 looking over the methods in use at the Saugus field laboratory, I do 

 not see how they can be much improved. 



There are several points, however, to which it might be well to call 

 attention. A few species of parasites have been and are being received 

 in great abundance, and these are no doubt among the most efficient 

 agents for keeping their hosts in check in their native homes; but it 

 does not follow that these same species will do as well here, under our 

 climatic conditions, as their hosts have done. It is quite conceivable 

 that those same factors which seem to favor the host with us may 

 act unfavorably as against the dominant parasite. On the other hand, 

 those species which in Europe merely maintain themselves may find our 

 conditions to their liking, and may prove much more effective with us 

 than they are at home. Special attention should therefore be paid to 

 the minor parasites or those other enemies that are less numerously 

 represented, and they should be given at least an even chance to develop 

 under our conditions. 



It has been shown in a number of instances that Asiatic species of 

 insects do better on our Atlantic coast than do those from Europe; and, 

 as the gypsy moth occurs also in Japan, I think it very highly desir- 

 able that at least as much attention be paid to securing Japanese para- 

 sitic and predatory species as to obtaining those from Europe. I would 

 advise that, if necessary, a well-qualified man be sent to Japan to study 

 the species there, and to send into Massachusetts such parasites and 

 predatory enemies of the gypsy moth as are there obtainable. It is 

 not possible to obtain too many of such forms, and among the orientals 

 there may be one that is far superior to anything obtainable in Europe. 

 No chance should be slighted in this connection, and a man acquainted 

 with oni- conditions and in general with what has been already received 

 from Knrope could, in even a single year, determine what species should 

 lie collected and sent in. 



Another branch of work that I would recommend is the study of the 

 ili~r;i-es of the caterpillars of both irypsy and brown-tail, and their 

 dissemination, if possible, over the entire range of both species. I am 

 qii'te aware that insect di>ca>es are unreliable in many cases, and that 

 they depend largely upon weather conditions: lint when they are active 



