APPENDIX. xi 



priation, you might find it difficult to get it. This is merely a 

 policy suggestion. I can conceive that, even with the most thor- 

 ough work that can be done with Paris green in spraying trees, a 

 few might escape and start a new colony. Then in another twenty 

 years this thing would come up again. 



Professor SHALER. Do you gentlemen agree that we must look 

 forward to a careful and continuous work against this moth ? 



Professor RILEY. As I said before, we have nothing to do 

 with the experience or methods of Europe, where the insect pre- 

 vails over vast areas, and where nobody expects to exterminate 

 it. Yet there have been instances of similar extermination, as, 

 for instance, what the Prussian government did with the potato 

 beetle ; and here you have an opportunity to show that you can 

 stamp this thing out. I expect a few will escape. That is why 

 I made the suggestion that it would be wise to introduce such par- 

 asites as can be used against it, with a view of permitting them 

 to search out those which may have escaped. The matter, as I 

 said, may not be possible ; but, if it is, it is only possible in that 

 way, and all other efforts would, I think, be rather puerile, and 

 serve to bring the whole thing into popular disfavor. Set the 

 school-boys to work on the eggs ; that is good as a prophylactic 

 measure, and would do a certain amount of good, but the good 

 would be very slight as compared with the effective work you 

 ought to do in the actual destruction of the caterpillars. As I 

 said before, the fact that the insect has been diminished in num- 

 bers would be rather against the efficient extermination of the 

 larvae in summer, for the reason that it is harder to find an isolated 

 bunch of caterpillars in a county than when they are numerous. 

 I still hold to the belief that whatever funds the Legislature can 

 give you should be devoted to a prompt and effective attempt 

 at stamping out. 



Professor SHALER. Suppose every tree sprayed, what reason 

 have we to believe that we should have disposed of the pest? 



Professor RILEY. There would be need for some years after- 

 ward of the greatest care. I would not attempt to kill the young 

 caterpillars ; wait until they are somewhat advanced, so that the 

 work could be concentrated within a narrow limit of time. 



[At this point Mr. Scudder came in.] 



Professor SHALER. The discussion has been, Mr. Scudder, on 

 the question as to whether it would be well to proceed at once to 

 the destruction of the eggs. There are places where the eggs are 

 abundant, and, as we know, they are conspicuous, and it seems 

 that between now and hatching time we might collect a consider- 

 able per cent, of them, paying for them by weight or measure, 



