54 THE FLORIDA BUGGIST 
Another type that gave good results was wooden boxes, seven 
by seven inches square by thirteen inches deep, painted black 
or dark green inside, or lined with black or dark green cloth. 
A joint of six-inch stovepipe was also used with good results. 
Other sizes, shapes and colors of crocks and boxes were used, 
but it was found that the traps of small diameter and a depth 
of twice the diameter gave the largest catches. No noticeable 
difference was found between the black and the dark green 
cloth, but the cloth lined boxes gave slightly better results than 
the painted ones. It is well known that mosquitoes seek a 
dark place in which to hide during the day and anything that 
furnishes this condition and is nearly air-tight so that they 
can be easily killed with a fumigant can be successfully used. 
Mosquitoes, in common with living things in general, are 
positively phototactic up to a certain degree of light intensity, 
and negatively so after this is exceeded. With mosquitoes this 
optimum, or turning point, is commonly met a little before 
sunrise. it 
The traps were placed in various positions and kept un- 
covered during the night. They were covered from 7:00 to 
7:30 in the morning, before the direct rays of the sun reached 
them. <A board or piece of stiff cardboard makes a good cover, 
but the best and most convenient cover found was a wooden 
frame covered with wire gauze with a piece of cardboard cut 
to fit. This cover allows an examination of the contents and 
the addition of the killing agent without any danger of escape. 
Gasoline was found to be the cheapest and most effective 
fumigant. It was added at the rate of 14 teaspoonful per 
gallon capacity of the crock, and about twice this amount for 
the boxes, when they were covered in the morning, the amount 
depending somewhat upon the temperature, more being re- 
quired on a cold day when vaporization was slower. From 
fifteen to twenty minutes was found sufficiently long to leave 
the traps covered. If the specimens are to be kept for future 
study, no more gasoline than will readily vaporize should be 
added, for otherwise the specimens will be wet and bedraggled. 
If they are not to be kept, a pint of boiling water poured into 
the crock quickly kills them. 
The position of the trap is very important and upon it de- 
pends its success or failure. Most of the tests were made on 
porches (Fig. 31), at 203 W. Ninth Street, South, and 2300 W. 
Hernando Street, Gainesville, Fla., but traps were tried for 
