CHEMOTROPIC TESTS WITH THE SCREW-WORM FLY 
29 
Table 2. — Best repellents against Cochliomyia macellaria — Continued 
Material 
Coeffi- 
cient • 
Num- 
ber of 
treated 
jars 
Number 
of flies in 
treated 
jars over 
checks 
Infesta- 
tion: 
Number 
of in- 
fested 
treated 
jars over 
checks 
Emer- 
gence, 
treated 
over 
check 
jars 
Pine tar 
Beta-naphthylethyl ether 
Pine-tar oil. . 
Powdered deer-tongue leaves 
Clove powder.. 
Pyridine. 
Derris powder 
Safrol (1) plus kaolin (4) 
Cade oil 
Salicylic aldehyde (1) plus kaolin (4) 
Coriander oil.. 
Furfural 
Pyrethrum powder 
Bergamot oil. 
Clove-bud oil 
Citronella oil (Ceylon) (3) plus petrolatum (1). 
Citronella oil (Ceylon) (1) plus kaolin (3) 
Crotonaldehyde 
Pine oil, pure steam distilled 
Alpha-nitronaphthalene 
Iodoform... 
Alpha-bromonaphthalene 
Wood creosote 
Spearmint oil J . 
Star-anise oil (1) plus kaolin (3) 
Rose-geranium oil... 
Pine oil, pure amber steam distilled 
Pennyroyal oil... 
Clove oil 
Wood naptha (1) plus pine-tar oil (1). 
Nitrobenzene 
Nutmeg oil 
Star anise oil.. 
Hexachloroethane 
Cinnamon oil... 
93:2,373 
60:1,506 
35:798 
16:366 
71:1,502 
68:1,447 
30:634 
8:168 
59:1,207 
9:185 
67:1,331 
81:1,527 
50:862 
22:366 
54:893 
7:113 
7:113 
23:357 
42:647 
10:151 
76:1,116 
67:941 
35:465 
119:1,561 
9:113 
91:1,136 
51:617 
206:2,209 
105:1,107 
19:198 
132:1,378 
15:154 
142:1,456 
16:154 
196:1,969 
11:16 
7:9 
12:12 
1:1 
9:12 
10:10 
5:5 
2:2 
11:11 
2:3 
6:7 
16:17 
6:6 
1:1 
5:5 
2:2 
2:2 
4:4 
4:8 
1:1 
4:4 
5:5 
6:7 
9:9 
2:2 
4:5 
2:3 
5:11 
9:10 
2:2 
13:16 
2:2 
7:11 
2:2 
10:12 
0:6 
0:6 
0:3 
1:1 
0:4 
0:4 
0:4 
0:- 
0:6 
0:- 
1:4 
0:7 
0:6 
0:1 
0:2 
0:4 
1:4 
1:1 
0:4 
0:3 
0:1 
1:6 
1:4 
0:2 
0:2 
1:3 
0:0 
0:5 
0:1 
0:4 
1:1 
0:4 
l The figures in this column correspond to those in column 6 of Table l,i. 
entire period. 
percentage ratio for ths 
These best repellents may be classified in the following groups: 
Halides. Benzyl chloride, para-xylyl bromide, iodoform, hexachloroethane, 
alpha-bromonaphthalene. 
Phenols. Guaiacol. 
Aldehydes. Furfural, benzaldehyde, salicylic aldehyde. 
Chlorine substituted ketones, Chloroacetone, chloroacetophenone. 
Halogen substituted esters. Beta-bromoethyl acetate, beta-chloroethyl 
acetate. 
Ethers. Beta-naphthylethyl ether. 
Nitro compounds. Nitrobenzene, chloropicrin (trichloronitromethane), picric 
acid (trinitrophenol) , alpha-nitronaphthalene. 
Amines. Alpha-naphthylamine. 
Miscellaneous nitrogenous compounds. Pyridine. 
Inorganic compounds. Copper carbonate. 
Essential oils. Clove-bud oil, artificial sassafras oil, clove oil, Ceylon citronella 
oil, cade oil, coriander oil, bergamot oil, spearmint oil, star-anise oil, rose-geranium 
oil, pennyroyal oil, nutmeg oil, cinnamon oil. 
Miscellaneous vegetable products. Pyrethrum, derris, clove powder, pow- 
dered deer-tongue leaves. 
Pine products. Pine oil, pine tar, pine-tar oil, turpentine, etc. 
It will be noted that one of the halides (alpha-bromonaphthalene), 
the only ether studied (beta-naphthylethyl ether), one of the nitro 
compounds (alpha-nitronaphthalene), and the better of the two 
amines studied (alpha-naphthylamine) are all naphthalene deriva- 
tives. Naphthalene itself was tested at times when too few screw- 
worm flies were present to enable a conclusion to be drawn. 
