1915} Behavior of Anopheles 251 
Reference was made to the habits of the night-jars*, which 
appeared when mosquitos were in flight and fed on them. The 
numbers thus eaten are not large. The main food of these 
birds consists of hemiptera and ants. Bats were noted only 
sparsely, while tree frogs, spiders and lizards were seen fre- 
quently catching Anopheles. By far the most destructive 
agent in the mosquito’s environment is man and his various 
measures. 
The ‘effect of oils rubbed on the skin, as a repellent to 
Anopheles, was tried out at the marsh, but the negroes who 
smeared themselves concluded the oils were more bothersome 
than the mosquitos. Pyrethrum was also burned. The method 
used was to place a negro into each of the four mosquito-bar 
nets and after about two hours of exposure, the nets were tied 
at the bottoms, placed into a closed room and the mosquitos 
killed with sulphur dioxide. The tent with burning pyrethrum 
was the furthest away so that the wind would not carry the 
fumes to the other tents. 
| Oil of Oil of 
| Sassafras Creosote | PYtethrum Check 
: a | ae. 
/Mionbaaginie cen aaeoeaber cee al 6 4 3 5 
‘aireriankeeollewegis 4 Se sbaace es 5) 508 163 298 321 
Meeniochynehtts.). 4. .4.0.. | 2 5 2 28 
Giulextsppy wire iscctersh cen | 19 13 | 12 69 
TUS, etme eae Nees SSOS 7 ik 5 he 185 315 423 
The oil of creosote was the most effective repellant, whereas 
oil of sassafras seemed to attract Anopheles. Reduction was 
most marked with the culex spp. The men in the nets reported 
many instances of Anophelenes biting through the film of oil. 
There is a fruitful field of investigation still open, which should 
yield a substance with which we may attract thousands of 
mosquitos, and by the arrangement of traps, destroy these. 
Experiments on the Zone yielded nothing worth while so far. 
* The weight on the stomachs of the four birds killed was: 3.55, 3.5, 4.05 and 
3.9 gms. They contained 49 large yellow ants, 30 pentatomids, 6 coleoptera and a 
mass of greatly disintegrated insect remains. In the esophagus were found five 
Anopheles, and in the mouth cavity of one bird were two more. 
