INTRODUCTION 
This is the fourth in a series of paperB designed to review all 
available inf ormatdon on the insecticidal uses of rotenone and the 
rotenoids. Part I reviewed tests with Derris, cube, timbo, Tephrosia, 
Mundi'.lea, and their constituents on members of the orders Collembola, 
Orthoptera, Dermaptera, Odonata, Isoptera, Corrodentia, and Mallophaga, 
Apparently no tests have been recorded of the effects of the rotenone 
plants upon Thysanura, Ephemeroptera, or Plecoptera. Part II reviewed 
the tests that have been made on Thysanopteraj Part III, the tests on 
Homoptera; and part IV, the present paper, reviews the tests that have 
been made en Hemiptera. 
HETIIPTERA 
Cimicidae 
Cimex lectularius L., the bedbug 
Daniels (15) in 1905 wrote that for some time derris had been 
used most succes'sTef ly to destroy bedbugs in jails in Perak, British 
Malaya. 
Lclndoo, Sievers, and Abbott (59) in 1919 reporter! that derris 
was tested against bedbugs by placirg~ZO bugs in a jar with a quantity 
of excelsior and then thoroughly dusting the contents of the jar. In 
nine tests under these very severe conditions 24.4 percent of the bugs 
were killed in 24 hours and 52.8 percent in 4 days. The authors con- 
cluded that derris would be of no practical value against bedbugs. 
Kelsall et al. (53) in 192S confined a number of bedbugs in a 
vial with derris dust. They were active for 2 hours, but all were dead 
after 3-1/2 hours. 
DeBussy et al.. (7_) in 1"35 reported that the bedbug proved insen- 
sitive to rotenone and to derris powder. 
Van dcr Laan (55_) in 1936 reported that the bedbug was not affected 
by derris. 
Eau.de ( 59) in l r "39 discussed the pros and cons of bedbug control. 
One State (not specified) recommended rotenone spray for bedbug control. 
The use of powdored insecticides in bedbug control is generally unsatis- 
factory because of the difficult'' in getting -the material into cracks 
and crevices where the insects abound. Pyrethrurn and derris powders 
are vGr r toxic to bedbr.es when the*'' can be hit with the dust but have no 
value against- the eggs. In a liquid insecticide designed primarily for 
bedbug control, it is generally advisable -to have a concentration of 
approximately C.l to 0.2 percent of actual rotenone in an oil base of 
suitable viscosity. Ethylene dichloride, cyclohexanone, and a number 
of patented solvents are being used with petroleum oils to increase the 
solubility of rotenone therein. The toxic a'ction of rotenone sprays 
against bedbugs is slow but may be effective for a week or more, a 
characteristic not found in other commonlv used contact insecticides. 
