- 73 
Thi3 species was somewhat more susceptible than Aedes . aegv pt.j to chlor- 
dane spray residues. Buildings sprayed with 2.5 percent chlordane in kero- 
sene to give a deposit of 200 rag. chlordane per square foot remained almost 
free of mosquitoes for 2 or 3 weeks, whereas in the DDT-treated "buildings 
the number remained very low for 15 weeks, — G-ahan _et al. ( l , 62 ). 
Chlordane may he effective as a residual poison on wallpaper for three 
months under certain conditions. The type of surface for residual insecti- 
cide application is highly important. At the end of 29 weeks DDT was more 
effective than benzene hexachloride or chlordane applied on a beaver wall 
board. The toxicity of chlordane on clay was very low after one week. 
Chlordane, benzene hexachloride, and DDT were much more effective on wall 
board than on clay. Chlordane spray, 200 mg. per square foot, was ineffec- 
tive a week after application on an all-metal shed. — Cutkomp (95) . 
The various insecticides in order of their residual effectiveness 
against adult A. q uadr imaculatus mosquitoes and house flies over a 26-week 
period were DDT, benzene hexachloride, chlordane, toxaphene, and TDE (DDD). 
Chlordane was tested in three combinations J (a) a 5-P©r cent chlordane kero- 
sene emulsion prepared by diluting a 25-percent chlordane, 5-percent 
Triton X-100, kerosene concentrate 1:4 with water; (b) a 5-percent chlor- 
dane xylene emulsion prepared by diluting a 35-percent chlordane, 4-percent 
Triton X-100, xylene concentrate 1:6 with water; and (c) a 2.5 percent 
chlordane xylene enulsion prepared by diluting the 35 percent concentrate 
1:13 with water. Application of 200 mg. chlordane per square foot was not 
satisfactory against adult female A. quadr imacul atus , at the end of a 16- 
week period. A 100— ag. dosage was not satisfactory at the end of an 8-week 
period. Application of 200 mg. chlordane per square foot against adult 
house flies was satisfactory for at least 8 weeks, while application of 
100 mg. was not satisfactory even at the end of 1 week. — Fay §t al. ( 136 ). 
Insectary-reared Anopheles quadr imacul atus mosquitoes were released 
in rooms which had been sprayed with insecticides at the rate of 200 mg. 
of the active ingredient per square foot. Chlordane, applied as a 5-per- 
cent xylene emulsion and as a 5-percent kerosene emulsion, compared 
favorably with DDT in initial knockdown, but displayed a shorter residual 
life. It was slightly more effective when sprayed as a kerosene emulsion 
than as a xylene emulsion. — McCauley jit aJL,. ( 306 ): Quarterman (380 ,). 
Cule x pipiens molestus Forskal 
A strain of this mosquito which was unaffected by contact with 0.2 
mg. DDT per square centimeter on glass was sensitive to 1/2 this quantity 
of chlordane. — Mosna ( 334) . 
Culex -pj-plens var. pall ens Coq. 
Mosquito pupae were immersed in aqueous emulsions of toxicants made 
by diluting a solution of 3 parts toxicant, 15 parts solvent naphtha, and 
12 parts sulfonated oil to varying concentrations. It was concluded that 
chlordane is about 9 times as toxic as £,2* -DDT at the LD-50; and about 
5 times as toxic as ^.E 1 -DDT at the LD-99.87. — Nagasawa (342). 
