344 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
THE CONTROL OF BREEDING OF YELLOW FEVER MOS¬ 
QUITOES IN ANT-GUARDS, FLOWER VASES 
AND SIMILAR CONTAINERS 1 
By James Zetek, Entomologist, Board of Health Laboratory, Ancon, C. Z. 
We find, continually, larvae of the yellow fever mosquito (Aedes 
calopus Meigen) in ant-guards, flower vases and similar containers. 
We have ample protection from yellow fever due to our intensive sani¬ 
tation and efficient quarantine, and perhaps, also, our calopus popula¬ 
tion is so low that no danger exists. But not all places are as fortunate 
as Colon, Panama City and the Canal Zone. Hence any method 
that will aid in the reduction of calopus breeding will have ready 
application. The method proposed in this paper is not offensive, it 
is easy to apply, and should result in a great diminution of these 
mosquitoes. Properly carried out it should eliminate a great deal 
of friction between the public and the sanitary corps. 
I am greatly indebted to Mr. Ignacio Molino, Jr., entomological 
laboratory assistant of the Bureau of Entomology, U. S. D. A., sta¬ 
tioned at the temporary field station at Ancon, for placing at my dis¬ 
position his big garden in Panama City, for carrying out experiments 
there, and for making the routine' inspections. This garden had forty- 
six ant-guards protecting choice rose bushes from the nightly ravages 
of leaf-cutting ants. 
To merely empty out the water each day or so, and again refil, is not 
enough because the calopus larvae cling tightly to the bottoms of the 
guards. The usual practise has been to pour some of our larvacide, 
or some crude oil, into the ant-guards. This “fixes” the larvae, but the 
rains wash out this insecticide, it gets at the roots of the rose bushes and 
as a result many of these are killed. Their productivity is always 
greatly lowered. Sometimes the ant-guards are purposely broken so 
they cannot hold water, a simple, effective way out of a difficulty; 
but this gives no protection against the ants. These measures, there¬ 
fore, only anger the owner and cause considerable ill feeling toward the 
sanitary corps. But this is not all; usually after finding larvae or 
pupae the second or third time, the owner is fined. This cannot leave 
him in a happy mood. As a result, cooperation suffers. Yet, the 
owner is not always to blame. The mosquitoes are domestic in habits; 
they must breed; ant-guards are favorable habitats for them. And, 
man has right to flowers. 
Vases in houses have always been prolific calopus breeders. It is 
also difficult to inspect thoroughly every house, and as a rule, the fact 
1 Published by permission of Col. H. C. Fisher, Chief Health Officer, The Panama 
Canal. 
