IV2 ANNUAL REPORTS 01 DEPARTMEN1 OF AGRICULTURE, 1951 
Studies of Biology and Control of Rone Flies Provide Significant 
Facta 
The biology of several species of horse flies was studied in ( Oklahoma 
and in Florida, in cooperation with the State experiment stations. 
Methods of rearing Larvae under Laboratory conditions were devel- 
oped. Earthworms, snails, and tendipedid Larvae were among the 
foods that appeared to be sat isfactory. The Btudies were made under 
funds authorized in the Research ;m<l Marketing Act. 
Habitats for the Larvae of several species have been Located in Okla- 
homa and in Florida. Of special significance is the finding that 
Tabanus 8idcifron8, an important species in Oklahoma, will develop 
in relat ively dry soils. 
Studies at Kerrville, Tex., show that sprays containing pyrethrum 
and tall oil air Less expensive and equally or more effective in protect- 
ing cattle from attack by tabanids than art' the combinations 
pyrethrum with piperony] butoxide or with other pyrethrum syner- 
None of the pyrethrum sprays arc now considered practical 
tor protect ing range cattle from attack by tabanids. 
High- and Low-Pressure Spray Applications Nearly Equal in 
Effectiveness for Control of Cattle Grubs 
The mortality of third-instar larvae of cattle grubs was about as 
high when rotenone sprays were applied at a pressure of L50 to 200 
pounds as at tOO to 150 pound-, as disclosed by studies in Texas, 
Oregon, and Georgia, in cooperation with the State experiment sta- 
tions. The number of second-instar Larvae present in the animals 
was too Low to permit evaluation of the effectiveness of the different 
pressures against this stage of the grub. The addition of 0.5 percent 
of a commercial detergent to the spray mixture caused do significant 
increase in kill of the larvae. 
Although it is recommended thai rotenone sprays be applied at 
pre— ure- of tOO pound- or higher, the results from Lower pressures 
compared favorably with those from higher pressures, under condi- 
tions of the tests. If high-pressure spray equipment cannot be ob- 
tained for grub control, stockmen are encouraged tot real their animals 
with available equipment that has a pressure of 200 pound- or higher. 
bnprovemenl in Livestock l)ij>> Soughl 
[nsecticide dips math' from some of the new insecticides are subject 
to deterioration on lone; standing in dipping vats. Toxaphene-emul- 
hoii dip, one of the most economical and effective dips for controlling 
ticks and oilier pests on cattle, may deteriorate after varying periods 
cf time, depending on the source of water and other factors. The 
deterioration of the dip creates hazards to the animal and may cause 
erratic results in controlling the parasites. Several toxaphene formu- 
lations under investigation appear superior to commercial formula- 
tions now available to the public Further field studies are necessary, 
however, before the formulations can be recommended \^v practical 
dipping operat ions. 
Tnig work was finance with fund- authorized under the Research 
and Market inc Act. 
