100 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



torch, and that made pretty fair headway, when the vegetation was dry 

 enough. In areas where there were large weeds and other large stems 

 it became almost an impossibility to make any headway with that type 

 of apparatus. 



Mr. W. H. Goodwin: In my tests last summer with oils, I found 

 that I could not use kerosene alone, but I could use kerosene in combi- 

 nation with a cheap lubricating oil known as a black oil. I found that 

 in order to get rid of weeds and plants I had to almost thoroughly satu- 

 rate the ground at the surface, and it must be nearly dry. When this 

 mass of oiled vegetation was set afire even two or three days after 

 spraying it burned to the ground. Now one of the problems with the 

 Japanese beetles is to clean out those waste places. It looks to me as if 

 this phase of the problem would apply to a certain extent to this corn 

 borer, by getting rid of all waste places as far as possible in the area in- 

 fested. 



Mr. W. C. O'Kane: In order to complete my information I w^ould 

 like to know the total area infested this year and last year. 



Mr. D. J. Caffrey: I can answer that question by saying that the 

 original survey in 1917 was made by one man, who attempted to find 

 out during his spare time the outside limits of the infestation and at 

 that time he found that about a hundred square miles w^ere infested. 

 This was during the fall of 1917, right after the insect was discovered. 



Now, last season we made a very careful survej^ during the spring, 

 summer and fall, and found that all together about three hundred and 

 twenty square miles were infested. That is quite an increase over the 

 area that we found infested at first, but I am not satisfied that the hun- 

 dred square miles was really the outside limit of infestation at that time. 

 As I said, there w^asn't time to make the original survey very thorough. 



Mr. W. C. O'Kane: Have you data for saying that the insect has 

 not spread very much during this past year? 



Mr. D. J. Caffrey: We have in part of the area at least. I am re- 

 ferring to the limits south and west of Boston, where in some places it 

 has spread only from a half to three quarters of a mile. 



In many of the towns in the north that add greatly to the area in- 

 fested we found only very few specimens after making a most exhaus- 

 tive search. 



Mr. W. R. Walton: In other words you are satisfied that the pre- 

 liminary survey was very incomplete. 



Mr. D. J. Caffrey: Yes, necessarily so, because there was very 

 little time spent on it. I think Mr. Walton's statement that the spread 

 of the insect has been comparatively slow is well founded. I might 

 mention another case of a market gardener in West Medford who was 

 a very observing man, an up-to-date grower in every respect, and he 



