- ?A - 
1926 
An anonymous writer (l) in the Gardeners' Chronicle in 1925 stated 
that insecticides derived from Derris elliptica may prove ultimately to 
"be the means of freeing us from the tise of arsenical sprays. Preparations 
of this kind are already on the market and appear to give excellent results. 
Reutter (79) in 1926 stated that an extract of derris plus to"bacco 
extract is used as a powerful insecticide, 
Vogt and Appel (105) in 1926, in their took "Die Cheraischen 
Pflanzenschutzmittel, " included Derris elliptica in a list of stomach 
poisons. 
Sishopp (5) in 1926 reported that fresh derris powder is exceed- 
ingly effective in destroying fleas on animals. All fleas on a dog v.'ill 
he destroyed hy one application of 1 gram or ahout three-fourths of a 
level teaspoonful of the powder. It is suggested that the material he 
mixed at the time it is used, \vith 2 parts of flour or cornstarch and 
dusted into the hair of the animal, cspocially along the back and neck, 
with a shaker. The skin of cats is much more easily injured with chemi- 
cals than that of dogs; hcnco any preparation used should Ije weaker when 
used on cats than on dogs. 
An anonjT-raous writer (2) in Korto Berichtcn voor Landhouw Nijverhcid 
en Handel in 1926 described the preparation of an insecticide spray; from 
derris root, Onl-j fresh root is used. A "bundle weighing l-l/2 catty 
(1 catty=l-l/3 pounds) is sufficient for a l/4-acre garden plot. It is 
chopped up, extracted in 2 gallons of boiling water, and diluted 1 to 4, 
It is preeminent among- chemical insecticides in that it does not harm 
even the most tender foliage. When used on dogs, it kills the fleas 
without irritating the skin, but should not be used in the presence of 
scabies. An extract of it is also used against the caterpillar and other 
harmful insects, 
Bishopp, Laake, Brundrett,- and Wells (6) in 1926 reported the 
results of tests of insecticides against cattle grubs or ox warbles. 
A proprietary derris extract, 1 jpart, plus 10 parts of water 
(containing 4 ounces of soap per gallon), killed 100 percent of cattle 
grubs (larvae of Hypo derma lineat'om ) when injected with an oil can 
directly into the grub holes in the ba,cks of cattle. Derris powder, 
8 ounces, plus soap, 4 ounces, per gallon of water, applied twice as 
a wash on the back also killed 100 percent of the grubs. Tests with 
dry derris pov/der, derris powder ■vvith paraffin oil, derris powder v/ith 
petrolatum, derris powder with soap and water, and derris powder with 
water only are recorded. 
The percentage mortality of Hypo derma bo vis is not so high as that 
of II, lincatum. 
