Vig 
EXPERIMENTS WITH KEROSENE ON THE COTTON-WORM. 41 
cent. of pupe that I had saved for various purposes were destroyed by 
Pimpla, Tachina, and Sarcophaga. 
Parasitized larve were easily distinguished by sluggish action and a 
change of color to yellowish green. 
As a means of prevention in Florida, and perhaps applicable to other 
sections, I would suggest destruction of cotton to prevent rattooning, 
and late planting for some years. 
It will readily occur to one as reasonable that if all cotton-stalks were 
uprooted by January 1st of each year, and no seed planted till March, 
the chances of survival of the hibernating moth would be at the mini- 
mum. < 
A singular experiment was tried this year, with apparent success. 
During June, July, and August a number of stumps and log-heaps were 
left slowly burning near a cotton-field so that the smoke would drift over 
the field at night. All other fields in the neighborhood are devastated, 
while this field is green and, except at the western edge, shows no action 
of Aletia.. 
This instance seems suggestive. Did the creosote from the smoke in 
some measure poison the cotton, or was the smoke obnoxious to the 
moth ? ' 
In some cases where } find the Palma Christi growing in cotton-fields 
there appears to be a scarcity of the cotton-worm in the vicinity, which 
may suggest its value as a protection. 
Jute has been abundantly tried, but with no effect perceptible, and 
this season I could not induce any planters to accept seed and try the 
experiment again. 
KEROSENE EMULSIONS. 
As directed, I have confined my experiments to emulsions of kerosene, 
and noted the effects of applications of such solutions upon the cotton- 
plants and cotton-worms. 
My efforts were made to determine: 1. Substances best adapted to 
emulsify kerosene; 2. Maximum dilution of kerosene destructive to the 
larve; 3. Minimum dilution of kerosene destructive to the cotton-plants. 
It was soon apparent that kerosene could not be used to advantage 
simply with water, from its tendency to collect at the top; nor if the 
water were made slightly alkaline or acid would much benefit be ob- 
served. 
A strong solution of various soaps made a good emulsion, presenting 
some points of advantage. 
Soda soap, potash soap, whale-oil soap, and other varieties were tried, 
but a cheap grade of yellow bar-soap, especially one in which rosin was 
largely used, proved best, and suggested the manufacture of a soap 
containing a still larger quantity of rosin, which could be cheaply sold 
for this purpose. 
After many trials I found that 4 pounds of this soap to 1 gallon of 
