30 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 1*951 
When incorporated in an aerosol, however, the scabrin showed little 
effecl on the house fly. Antibiotic tests with scabrin showed it to 
be effective .• - i_r i i 1 1 — t more than a dozen species of bacteria and fungi. 
It was somewhat toxic to rats, when fed by stomach tube, the mini- 
mum lethal dosage ranging from •''" to 200 milligrams per kilogram 
of body weight. 
The studies were conducted with funds authorized under the 
R nvli and Marketing A<-t of L946. They do not now warrant 
definite recommendat ions. 
N«'\> Materials Studied as Possible Insect Repellents 
Work on insect repellents at the Orlando, Fla., laboratory was con- 
cent rated on the development of materials that can be applied to cloth- 
ing to protect the Armed Forces from attack by mosquitoes, mites, 
flies, and ticks. Repellents or toxicants round useful against the dif- 
ferent arthropods are then combined in order to develop a general- 
purpose treatment. One such composition, designated M I960, gave 
very promising results. M I960 is composed of BO percent each of 
2-butyl-2-ethyl-l, 3-propanediol, benzyl benzoate, and n-buty] acet- 
anilide. Ten percent of an emulsifying agent is added so that the 
material can be diluted with water, the form in which the composition 
is used to t reat clothing. 
Snow-Water Mosquitoes Controlled in Oregon Resorl Areas 
Practical control of snow-water or mountain mosquitoes in the 
higher elevations in the Pacific Northwest appears possible through 
use of portable or fixed -pray equipment to treat resort areas. Satis- 
factory relief from mosquitoes was obtained by spraying with DDT 
or pyrethrum each day. Just before and after dusk, when adult 
mosquitoes -how a marked tendency to migrate, DDT -pray- did Dot 
always pro\ ide adequate relief, and pyrethrum -pray- were sometimes 
required. However, treatment wit 1 1 DDT during the day gave good 
control of the insects in the immediate vicinity oi the camp until the 
dusk migrat ion began. 
Treating Mosquito Breeding Grounds in Alaska Reduces Following 
Season's Mosquito Population 
Mosquito-control research in AJaska demonstrated that as little as 
0.3 to 0.4 pound of DDT an acre applied to an area of LOO square miles 
reduces mosquito numbers the following season by 95 percent. 
Application of Insecticides to Breeding \r«';is Offers Promise In 
Control of Sand M> 
Joint investigations by Florida mosquito-abatement districts, tin 4 
Florida State board of Health, and the Orlando, Fla., laboratory 
showed thai either dieldrin or chlordane applied to marsh area- w here 
-and flies breed provides excellent control of the larvae for several 
months. In small scale tests, dieldrin at the rate of l pound and 
chlordane at 2 pounds an acre showed particular promise. 
