-27^ 
number of poisons when fed to adult fruitflies. Three feeding media 
or "baits were used, (l) apple sirup, (2) molasses, and (3) cane 
sugar-glycerine. The apnle sirup and molasses were of ordinary com- 
mercial grade. .They ?ere diluted with tap " r ater before the poisons 
^ere added; the apple" sirup 'end molasses to concentrations 0^ 12.5 
oercent, and the cane and sugar-glycerine to 5-percent c&ne sugar and 
2.5 percent glycerine. Poisons were all comparer* at 6 concentrations, 
1:200, 1:400, 1:800, 1:1,600, 1:3, 200, and 1:6,400. A wad of cotton 
wool was thoroughly soaked in each of the poisoned "baits and the ex- 
cess liquid squeezed out. Finally each wad m as placed in the "bottom 
of a shell vial of about 20 cc. capacity and 10 flies ™ere intro- 
duced. After being loosely stoppered with cotton wool the vials 
"•^ere set away. Vials "ith unpoisoned baits ^ere included as con- 
trols. All tests were in duplicate, so 20 flies ^ere used at each 
concentration f or /f%g^rj^«' medium. Dead flies '--ere 'recorded daily for 
a week when the test was concluded. ; Derrisine gave an index of toxi- 
dity'of 20.4 in apple sirup, 29.3 in molasses, and 59.2 in the cane 
sugar-glycerine mixture. The -corresponding values for Derrisol were 
0.4, 0.7, and 2.0. Hotenone in cane sugar— glycerine gave an index 
of toxicity of 7.7. The mosttoxic material was S.S-dinittfo-orthocresol, 
^hich gave indices of -toxicity of 99.1, 95.8, and 91.6, respectively, 
in the 3 baits. PowcLered derris gave a toxicity index of 6.4 in the 
cane sugar-glycerine mixture, rr herees derris extract in glycerine 
(1:5) i"8s without toxicity. 
Drosophila sp. 
The adults ^ere used by the Federated Malay States Department of 
Agriculture (83) .in 1936 to test the toxic value of derris extracts. 
Craufurd-Benson (^34) in 1938 reported that larvae are not sus- 
ceptible to a derris preparation when dipped in it. ' 
Hip-ooboscidae 
Pseudolynchia canariensis (Macq.), the pigeon fly 
Bishopp (27) in 1929 reported that derris po-der ^as nearly as 
effective as pyrethrum powder. From one to three oinches of the 
powder, depending on the si?e of the bird, ^hen scattered among the 
feathers destroyed all flies present. T^o proprietary extracts of 
derris root used at .the rate of 1/2 ounce and 2 ounces to the gallon 
also gave a complete kil'll The slight staining of the feathers from 
the pyrethruii extract, especially on Hiite birds, might be somewhat 
objectionable. The derris products do not stain. 
lAelophegus ovinus .(L.). the sheep tick 
Wille et al. (322) in 1937 reported on the use of cube in dins 
against M. ovinus in Peru. In 1935 more than 300,000 sheep ■"ere treated 
