88 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



CONTACT SPRAYS FOR BROWN-TAIL CATERPILLARS 



By C. H. Hadley, Jr., Durham, N. H. 

 {Paper not received in time for publication.) 



Secretary A. F. Burgess: Mr. Siegler, one of Professor Quain- 

 tance's assistants, carried on some experiments with insecticides to 

 determine their effect on brown-tail moth caterpillars. I think his 

 results might be interesting. 



Mr. E. H. Siegler: Under the direction of Mr. Quaintance, 

 experiments with various miscible oils, alone and combined with 

 nicotine sulphate, were conducted in Maine and Massachusetts during 

 the season of 1913. The first test of the spray materials was directed 

 against the brown-tail nests and later, when the larvae were emerging 

 from their nests in maximum numbers, a second spray application was 

 made. 



A few days following the spraying of the nests, the nests were cut 

 and removed to the laboratory at Melrose Highlands, Mass. Although 

 the nests had been thoroughly drenched with the spray materials, the 

 larvae emerged apparently unaffected. The structure of the winter 

 nests makes it difficult for a spray material to penetrate sufficiently to 

 kill the insects within. Furthermore, with large trees, it is difficult 

 to thoroughly drench the nests unless a large amount of spray material 

 is used. 



As soon as the brown-tail larvae were emerging from their nests in 

 maximum numbers, they were sprayed with the miscible oils and 

 nicotine solutions. This work was carried out both in the field and lab- 

 oratory. In all instances the larvae were thoroughly drenched. The 

 results were not satisfactory. Owing to the hairy covering of the lar- 

 vae, the spray materials stood in small drops at the extremity of the 

 hairs, apparently not coming in actual contact with the body of the 

 larvae. The only material which gave satisfactory control was pure 

 kerosene. This could not well be used owing to the probable injury 

 it would cause to the host plant. 



Mr. C. H. Hadley, Jr.: The experiments which we conducted 

 were on small trees and in some cases we used eight quarts of material 

 to a single tree. So far as possible, we aimed to drench the caterpillars 

 in order to give the insecticide a good opportunity to penetrate. It 

 is doubtful if we would use as large an amount of material in our spray- 

 ing operations. 



President H. T. Fernald: Is there any further discussion? 



Mr. T. B. Symons: I move that we now take up the discussion of 

 the President's address. Carried. Vice-President Herrick takes the 

 Chair. 



