38 



ones. In 1911, Ochmann recommended potassium tellurate as an 

 internal remedy for repelling flies, but in the same year Mayer failed 

 to obtain results with this drug, and ib is probable that internal remedies 

 will never prove practicable in repelling flies. The powder remedies 

 that have been employed are pyrethrum powder and tobacco powder. 

 The former is prompt in action, but it is costly and its effect lasts only 

 for about a day. Tobacco powder has less kilhng power, but is more 

 satisfactory. Various oils, emulsions of oils, and mixtures of oils, are 

 used. Crude petroleum, cottonseed oil, fish or train oil, and light coal- 

 tar oil may be used pure. Jensen (1909) recommended the following 

 for dairy cows : Common laundry soap 1 lb., water 4 U.S. gals. (3'33 

 Impl.), crude petroleum 1 U.S. gal. (0-83 Impl.), and 4 oz. powdered 

 naphthalin. This mixture, which must be stirred well before use 

 and should be applied once or twice a week with a brush, is said to 

 protect cows for a week. Fish oil, rated as one of the best repellents, 

 has been used alone and in combination with various other substances. 

 Its protective action is said to last from two to six days, depending 

 on the temperature and humidity. In 1903, Moore recommended 

 the following mixture for use on dairy cows : Fish oil, 100 parts ; 

 oil of tar, 50 parts ; crude carbolic acid, 1 part. This mixture cost 

 about 3id. per gallon and was applied with a small hand spray pump, 

 one application being effective for two days. Bishopp's formula is 

 said to be very useful [see this Review, Ser. B, i, p. 98]. Laurel oil 

 is also an efficacious repellent. Mayer (1911) found that it gave pro- 

 tection for a period ranging from 2 to 12 days and that the irritating 

 effect produced by the pure oil — unless applied lightly — may be over- 

 come by combining it with linseed oil in the proportion of 1 to 10. 

 The present author found that 10 per cent, of laurel oil in cottonseed 

 oil was active for less than a day. The following results were obtained 

 in experimental tests : A 10 per cent, mixture of crude carbolic acid 

 (21 "8 per cent, phenols) in cottonseed oil has a strong repellent action, 

 but this lasts less than a day. Application must be made lightly with 

 a brush, since a heavy application with a spray pump is likely to cause 

 poisoning. These remarks apply equally to mixtures of 10, 20 and 50 

 per cent, of pine tar in cottonseed oil, and to 10 per cent, of oil of tar 

 either in cottonseed oil or in Beaumont oil. Mixtures of 10 per cent. 

 oil of citronella, oil of sassafras, or oil of camphor in cottonseed oil are 

 powerful repellents, but they are active for less than a day. A heavy 

 application of fish oil causes the hair to become sticky and fall out. 

 A light application did not produce these results. A bibliography 

 of 20 works is appended. 



Whitaker (Helen D.). Lice and Mites. — Washington State Agric. Exjpt. 

 St a., Pulhnan, Popular Bull. no. 74, October 1914, 7 pp. 

 [Received 16th February 1915.] 



This bulletin gives popular accounts of and remedies for Bermanyssus 

 gallinae (the common chicken mite), Cnemidocoptes niutans, which 

 causes scaly legs in fowls, and the common hen louse. Reference is 

 made to the statement by the U.S. Bureau of Entomology that the 

 pigeon-mite is a different species from the chicken-mite, and that 

 pigeons are not responsible for the spread of the chicken pest. 



