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To help eradicate ticks from a veterinary hospital, a mixture of 
derris and pyrethrum powder in equal parts was sprinkled in the cracks 
and crevices, and the dogs in the ward were dusted daily with derris 
powder (4 percent of rotenone) . The derris caused the ticks to re- 
lease their hold on the host in addition to killing them. The ward 
was thus freed of ticks.-— Koutz (345) . 
Extracts of timbo roots were very toxic to ticks in Brazil, and 
a treatment for infested dogs gave 99.4 percent mortality in 24 hours* 
—Meyer (415)* 
In Queensland arsenical and phenolio dips kill ticks on dogs but 
do not prevent larvae, nymphs, and young adults in the dogs* sleeping 
quarters from attaching themselves shortly after treatment. The use of 
derris was found to be the only way of preventing immediate reinfestation. 
—Roberts (507 ). 
Penthaleidae 
Halotydeus destructor (Tucker), the red-legged earth mite 
Penthaleus major (Dug.), pea mite or another red-legged earth mite 
Derris or pyrethrum dusts are recommended for these mites on 
garden plants in Tasmania.— Evans (171) . 
Recommendations for control in Victoria include dusting young 
plants with a mixture of derris powder and 2-percent nicotine dust 
(1x8) • Applications should be made every 3 or 4 days as long as the 
mites are present.—Pescott ( 464 ). 
In New South Wales excellent oontrol of Penthaleus major on beets 
was obtained with a spray of nicotine sulfate in white oil emulsion, 
and with a mixture of 1 pound of powdered derris and 8 pounds of a 
proprietary nicotine dust. Adequate control was obtained with a spray 
containing 4 fluid ounces of a 10-percent rotenone solution in benzyl 
alcohol, and 6 fluid ounces of emulsified white oil, in 5 gallons of 
water.--Wallace (651 ) • 
In Japan all the mites (P. major ) on wheat were killed by sprays 
of soap solution containing pyrethrum, derris, nicotine sulfate, or fish 
oil.— Tamura (580 ). 
Psoroptidae 
Otodectes cynotis (Hering), the ear mange mite 
An ointment consisting of 1 part of derris powder (5 percent of 
rotenone) in 10 parts of petrolatum or olive oil has been found effec- 
tive against this mite on dogs.— Price and Bishopp ( 47 5) . 
