- 8 - 
rata, 18 percent were wormy and 16 percent stung, and of 93 check plugs 
(water plus alcohol) 95 percent were wormy and none stung*— Si egler 
and^ coworkers (42) ♦ 
A mixture containing ricin, the toxic ingredient in castor-bean, 
was the least effective material used against the European red mite 
in 1942«— Boxume and ^itcoinb (15) » 
Unsatisfactory materials tried in 1942 against the common red 
•pider on greenhouse plants included a preparation containing castor- 
bean extract (ricin) Ifhitcomb and coworkers ( 61) • 
A spray containing castor-bean extractives in 1943 was inef- 
feotive against the onion thrips, chiefly because of its oily nature 
and poor wetting qualities*— Bourne (l2) . 
Powdered or crushed seeds *-- 'The powdered beans or husks, free 
from oil, killed all the honeybees tested} but some of this powder, 
extracted with a 10-percent solution of sodium chloride, apparently 
did not kill any of the bees* The powder had no effect on webworms, 
but had a slight effect on silkworms, flies, and grasshoppers*— 
Uclndoo and Sievers (33 , p* 9) * 
Crushed castor-bean seeds incorporated in bran-mash baits were 
not toxic to grasshoppers*— Hartsell and '^ilcoxon (26, p* 136)* 
The ground cake of the castor-bean had no effect on fly laznrae 
in manure*— Cook and Hutchison (18, p* 4)* 
Castor-bean cake has been used as an insecticide in India*— 
Roark (41, p. 34). 
Castor oil *— [No attempt has been made in this review to 
include refersnoes to derivmtivM of castor oil useful as inseo- 
ticides or adjuncts*] Castor 6il, either alone or mixed wildi sugar, 
attracted houseflies and was an active poison for them* Since 
other oils, e* g*, olive or nut oil, had no such toxic action, the 
action of castor oil was not merely mechanical* Adding 2 drops 
of orotom oil to 1 ounce of castor oil greatly increased the toxio 
action on flies*— Boye'' and Guyot (14) » 
The following poisonous bait was recommended for houseflies 
in dwellings in Franoei Castor oil SO gm*, oroton oil 2 dropsy 
mixed with sugar or molasses* The effect was stated to be in- 
stantaneous*— Chavigny {17, p* 510)* 
During the fly plague in Germany in 1930 castor oil was used 
as one measxire of control* It had a very toxio effect upon adult 
flies, and was readily taken by them if it was mixed with sugar 
or mola88e8*>*f(xerasa39!rJ«Belchsgesundheitsamt (20, p* 30)* 
