ECONOMIC ZOOLOGY — ENTOMOLOGY. 



153 



Applications of blackleaf tobacco extract containing 2| per cent nicotin at 

 dilutions varying from 1 gal. to 75 to 200 of water killed all uymplis hit. 

 Blackleaf " 40," which contains 40 per cent nicotin, used at strengths of from 

 1 to 1,000 to 1 to 1,750 killed all the nymphs hit, and at a strength of 1 to 2,000 

 killed all but fully developed nymphs. Three acres of a vineyard at North 

 East, Pa., was sprayed in 1 day at a cost of $7.40, $2.40 of which was expended 

 for the blackleaf tobacco extract as applied at a dilution of 1:150, or a total 

 expense of $2.47 per acre. A badly infested vineyard of 11 acres was sprayed 

 July 14 to 16 with blackleaf extract 1 : 100 at a total cost of $3.75 per acre. On 



3 blocks in which the strength of the blackleaf tobacco extract varied from 

 1 : 75, 1 : 100, and 1 : 150, so far as could be observed the 1 : 150 dilution was as 

 effective as any. All of the applications mentioned were made before any of 

 the nymphs had completed the final molt and all were highly effective in reduc- 

 ing the number of the nymphs to a point where their injury for the remainder 

 of the season was very slight. 



Some synonymy and other notes on Aphidiinge, A. B. Gahan (Proc. Ent. 

 Soc. ^^'ash., 12 {1910), No. J,, pp. 170-180). ^This paper includes notes on the 

 host relations of several parasites of this subfamily, the hosts of which have 

 heretofore been unknown. The author also records the occurrence of 4 Euro- 

 pean species not hitlierto credited to our fauna. 



The use of potassium permanganate against the woolly aphis, R. Ahbens 

 {Geisenh. Mitt. Ohst u. Gartcnbau, 25 {1010), No. 11. pp. 182, 183; ahs. in 

 Internat. Inst. Agr. [Rome], Bui. Bur. Agr. Intel, and Plant Diseases, 1910, 

 Nov., p. 17Jf). — Favorable results are retorted to have been obtained through the 

 use of a 1 per cent solution of potassium i)ermanganate. 



Recent results of compounding miscible oils for use in controlling white 

 fly, W. W. YoTHERS and S. S. Grossman {Fla. Grower, 3 {1911), No. 21, p. 7).— 

 The authors present 4 formulas that they find to give satisfactory results 

 in combating the citrus white fly, viz, (1) caustic potash whale-oil soap 1^ 

 gal., crude oil (not distillate oil) 24° Baum^ 3 gal., water to emulsify about li 

 gal.; (2) caustic potash whale-oil soap 2 gal., distillate oil (gas oil) 30° Baume 



4 gal., water to emulsify about 2 gal.; (3) caustic potash whale-oil soap 2 gal., 

 paratfin oil (diamond paraffin oil) 28° Baiune 3 gal., water 1 gal.; (4) caustic 

 potash whale-oil soap 2 gal., pai'affin oil (junior red engine oil) 25° Baume 3 

 gal., water 1 gal. Each of these contains sufficient ingredients to make up 200 

 gal. of spray material at a cost of about 63 cts., 84 cts., $1, and $1.05, respec- 

 tively. 



The experimental results obtained from the use of these formulas have been 

 summarized in the following table : 



Summary of spraying experiments toith miscible oil compounds. 



For summer use, formulas (3) and (4) should be diluted to make 300 gal., or 

 spray material containing 1 per cent of oil, 



