-75- 
Lv. Jrr 'i' ny, referred, to a special contact poison that apparently contained 
derris and was used in admixture ™ith summer oil spray. 
Ceratitis ( Pterandrus ) rosa (Karsch) 
Ripley and Hepburn ( 240 ) in 1931 reported tests to determine the 
comparative toxicity to the w atal fruitfly of fluorine compounds, lead 
arsenate, copper carbonate, Derrisol, and Pulvex. The tests were made 
by suspending a cylindrical roll of absorbent cotton wool, 8 inches long 
and 1-1/2 inches in diameter, from the center of a cage 1 foot square 
and containing 50 flies, 25 of each sex. The cotton hsd been soaked in 
a solution containing 62.5 gm. of white sugar per liter, plus the poison 
being tested. Derrisol diluted 1 part to 500 parts of sweetened water 
acted neither as an olfactorv nor a gustatory repellent and showed a 
high toxicit - "- considerably greater than that of lead arsenate at 0.23 
percent. It appeared to be somewhat too volatile, however, always failing 
to kill 10 percent or more of the flies, these having fed presumably 
after the rotenone had largely volatilised. Pulvex was far less toxic 
than Derrisol, dilutions of 1 part to 300 of sweetened water ranking con- 
siderably below Mally bait in toxicity. 
Dacus cucurbita.e (Coa.), the melon ; fly 
The Federated"- Malay States Department of Agriculture ( 84 ) in 193? 
reported on tests' made in 1936. Spraying and immersion tests with adults 
as subjects, "-ere carried out ^ith aqueous solutions of Derris elliptica , 
rotenone, lime precipitate of derris, deguelin, rotenone-free resin 
solution, and solutions of the new solid and liquid derivatives of derris. 
Rotenone -and deguelin were dissolved in acetone to which a small amount 
of Agral was added ^nd the new solid was tested in solution in ethylene 
glycol monoethyl ether. In some tests this species was anaesthetized with 
ether before being sprayed. 
Dacus ( Chaetodacus ) sp. 
The adults were used by .the Federated Malay States Department of 
Agriculture (83) in 1936 to test the toxic value of derris extracts. 
E p ochre, canadensis Loew, the .currant fruitfly ■ 
Wood ( 325 ) in 1912, in describing the use of derris as an insecticide 
in Malaya, stated that its use against the- gooseberry maggot in English 
orchards would be well worth a trial. ' 
Hanson and Webster ( 136 ) in 1938 recommended derris dust (0.5 percent 
rotenone) or spray (0.02 percent rotenone) for the control of the yellow 
'current fly. 
