
-21- 
The total catch of all species of blowflies, including the screw- 
worm fly (Cochliomyia macellaria Fab.), taken by D. C. Thurman and S. M. 
_ Perry in the trapped area near Menard, Tex., during the latter part 
of June and the first half of July, was 1,982.5 quarts. H. E. Parish re- 
ports 135 new cases of screw—worm infestation in the trapped area as com-— 
pared with 215 in the nontrapped area. 
H. H. Stage, Portland, Oreg., reporting a study on the effec-— 
tiveness of oils in mosquito control, says: "These trials demonstrated 
the following results: First, that all oils killed the first day of ap- 
plication; second, that all the Diesel oils killed the second day after 
_epplication; third, that the lighter oils gave partial kill the third 
Gay; and fourth, that no oil gave any real amount of protection there- 
after. (The 'Mapco' larvicide completely lost its effectiveness after 
the first day.) 
"The spreading qualities of the 14 oils were tested by dropping 
0.1 cubic centimeter of the oil sample while held an inch above the water 
surface. Measurements were then made of the diameter of the circle 
formed by the oil. Several tests were made with each oil, both in clear 
end in muddy water. * * * The average spread of all oils tested was 
11.6 centimeters in clear and 8.3 centimeters in muddy water. The spreed— 
ing qualities of the various oils were further tested by adding 5 per cent 
of the larvicide, 1 and 2 per cent crude carbolic acid, ard 1 per cent 
cresylic acid (97 per cent pure). Tests were made both in the laboratory 
and in the field. It was found that an addition of 5 per cent of the 
"Mapco' larvicide or an addition of 2 per cent crude carbolic acid in- 
creased the spread of the Diesel oils from 10 to 20 per cent. The 1 per 
cent crude carbolic acid and 1 per cent refined cresylic acid gave a very 
slight increase if any. It was further shown that the eddition of larvi- 
cide or carbolic acid did not noticeably add to the killing power of the 
oil, but that oils containing 5 per cent larvicide or 2 per cent crude 
carbolic acid did cause the oils to spread quicker and better than the 
same oil without the addition of such material. It was also shown that 
the addition of such material greatly increased the efficiency of the oil 
-under field conditions, especially where the vegetation or debris was 
' heavy." 
Some very interesting studies of breeding places of sand flies 
have been conducted at Charleston, S. C., by W. E. Dove and assistants. 
Based on studies of samples of muck obtained from marshes, it is found 
that the development of sand fly larvae is restricted to areas which re- 
ceive enough seepage to retain moisture, that otherwise larvae are found 
- only in shaded areas in the edges of marshes, and that throughout the 
summer sand flies have been recovered only in the low areas which did not 
become dry. The significance of this situation in control is noted. 
Further reports are also made on the efficiency of creosote oil and re- 
lated products. It is reported that. a mixture of these products in the 
-laboratory killed sand fly larvae in dilutions of 1 to 2,500 and that this 
: product is fairly soluble in water. Field spraying tests with this are 
_ being instituted which, as pointed out, if successful will involve prin- 
cipally the labor cost. 
