-92- 
animals, but the results obtained were not conclusive, '.'/hen derris 
powder was tested on botfly larvae, under laboratory conditions, it 
killed slowly and, in some cases, required retreatment to secure a 
kill. — Haseman and Roland (269 ) . 
Hippoboscidae 
Melophagus ovinus (L.), the sheep tick, sheep ked 
When pupae of mixed ages were immersed in a solution of rotenone 
the percentage of emergence was not materially affected.— Commonwealth 
of Australia (118 , p. 30). 
Derris is particularly suitable for the control of the sheep 
ked.— Freak (199). 
There are three kinds of dips used for eradicating sheep ticks at 
one dipping, namely, fused-bentonite-sulfur-cube, arsenic-sulfur-rote- 
none, and home-made derris or cube dip. When used according to the 
instructions furnished, they are eff ective.~Imes and Babcock ( 307 ) ; 
Thorns sen and Doner (591 ) . 
All the preparations containing arsenites, phenols, and rotenone 
were effective in New Zealand against the adult keds on sheep, and 
trials indicated that derris gave the necessary delayed action so 
that the keds emerging from pupae were also killed.— New Zealand De- 
partment of Science and Industry (445 ) • 
A rotenone-sulfur dip was tested in New York on about 2,000 sheep, 
representing a number of farm flocks and all the common breeds. In 
addition, three county rings used this formula on approximately 10,000 
head. The result was the ert lication of the sheep tick in all flocks 
dipped. Only one dipping was necessary, and this usually occured short- 
ly after shearing. "While this dip does not kill the pupae it remains 
effeotive long enough to kill all young ticks emerging from the pupae 
which were present at the time of dipping. The formula follows: Cube 
(5 percent of rotenone) 10 pounds, wettable sulfur 100 pounds, and 
water 1,000 gallons. Wettable sulfur alone will usually eradicate this 
pest but it is too slow, and a fixed nicotine-sulfur dip was also good 
but was not uniformly eff icient*— Schwardt and Matthysse (530 ) • 
In 1942, 700 sheep infested with this pest in Colorado were dipped 
once in a suspension of 4 ounces of derris powder (5 percent of rote- 
none) per 100 gallons of water. None became reinfested during frequent 
inspections in the course of the following 92 days, during which time 
they mingled with infested sheep.— U. S. Bureau of Animal Industry ( 613 ) . 
