GASTROPHILUS HAEMORRHOIDALIS AND OTHER BOTS. 47 
dicated in Table XI, infested hair was placed in tubes at air tempera- 
tures of a living room and allowed to remain until larve were well 
formed and ready for emergence. Some of the eggs were then tested 
and the viability determined. A check was not kept, as the brownish 
color of the dead larve easily distinguished them from the trans- 
parency of the active larve. 
TABLE XI.—Effcctiveness of washes upon eggs of Gastrophilus intestinalis, 
Aberdeen, S. Dak., 1915-16. 
Num- Mortality of larve. 
Date Ex. ber 
eggs Insecticide. osure. | larvee Remarks. 
treated. Pp ex- | Dead. Living. | Doubt- 
amined. Ele ta talk 
1915, Minutes 
Sept. 6 | Refined petroleum 6-18 7 0 7 0 | Engine oil, No. 1. 
Dos: se=t2 Oe SS esac cas eso as 18-31 8 4 4 0 Do. 
1916. Hours. 
moepts <7) Kerosene..2-4-..--2------ 24 20 aS) Je es if 
Do...-| 1.85 per cent phenols! .... 24 38 38 0 0 | Reddish brown in color. 
Do....| 2 per cent nicotine sul- 24 17 12 5 0 
phate. 
Do-..-.| Carbolic acid 2 per cent 24 20 19 1 0 
phenol. 
Wo ees Mudra e Slee aowssicce scien 24 20 0 20 0 
Do....| Nitrobenzine gas......--. 25 38 38 0 0 
Sept. 9 seen acid 2 per cent 5 28 23 0 0 | 2larvee yellow in color. 
pheno 
Woe=24|) Kerosene. + ---2-2-- Basen 29 22 5 Mi) ee eeee 5 dead larvee yellow in 
color. 
Do 0.185 per cent phenols 1 29 23 23 0 0 | 3 dead larve yellow in 
color. 
Sept. 11 | Nitrobenzine gas. -.....-. 4 34 a 22 5 
DWOLS es s-255 Onesies cciisbis eos = 10 40 Eff) ee eee 3 
DOs eye ses2 G0) eee een ee 25 42 42 0 0 
Do..-.-.| 0.054 per cent phenols}... 26 40 40 0 0 
ID Oba | PCCEOSENC S05 cc eae ee 25 28 5 Pla eed o § 18 larvee very active. 
Do....| 2 Dey cout nicotine sul- 26 26 9 14 3 
phate, 
Do...-| 2 per cent carbolic acid... 26 38 38 0 0 
Sept 152} Kerosene..........-....-- 24 55 11 38 6 | 38 larvee very active. 
Do.1. .| Carbolic acid 2 per cent 24 48 47 0 1 
phenol. 
Do.1. | 0.054 per cent phenols !. .- 25 49 49 0 0 
Dow | ierosenes-- sae) 2 2 147 24 3 19 2 
Do.!..| Carbolic acid 2 per cent 146 27 27 0 0 
phenol. 
Do... .| 0.054 per cent phenols!- - - 147 21 21 0 0 
1 A proprietary compound of cresol in combination with resin soap. 
2 Eggs not well incubated were treated and larvee removed Sept. 21. 
In the tests with larvee removed from the eggs it was observed 
that the minimum period causing death by contact was 1 minute 
with pine tar 1 part and kerosene 2 parts. The ease with which 
either of these can be obtained suggested a study of these and similar 
substances. 
It will be observed that kerosene, which is commonly reported 
to be in use by farmers, even at an exposure of 147 hours, had prac- 
tically no effect upon larve. When eggs upon hair were rubbed 
they more readily yielded to hatching and apparently the larvee were 
more active than from any similar treatment. The kerosene seemed 
to facilitate the emergence of the larve. While it was ineffective 
against well-developed larve, it was thought that upon freshly 
