CONTROL MEASURES FOR CARRIBEAN MOSQUITOES 
361 
Fig. 3. Concrete inverts and pipe made in the 
“Plantel” at San Miguel, Republic of El Salvador. 
The pipe was used for subsoil drainage. 
Fig. 5. This ditch at Santiago, in the Republic 
of Cuba, is lined with thirds of concrete pipe 36 
inches in diameter instead of inverts. 
Fig. 2. A culvert over a large drainage channel at 
La Chorrera, Republic of Panama. This ditch-was 
paved with inverts and the sides faced with stones 
set in cement. 
ment, the Army, the Navy, engineers, and 
contractors. In the Canal Zone inverts 
cost about 45 cents apiece, including the 
expense of plant amortization and super¬ 
vision; 
The medical department of the United 
Fruit Company lays considerable emphasis 
on repeated applications of larvicides to 
anopheline breeding places. Screened 
houses are widely used and concrete gutters 
and drains, always in evidence on the Fruit 
Company property, do much toward reduc¬ 
ing mosquito breeding. 
An intensive antimosquito campaign 
started in the larger camps of the Tropical 
Oil Company of Colombia, in 1926, reached 
its maximum in 1927 and 1928, and since 
that time the mosquito control program has 
Fig. 4. A ditch lined with inverts, side slabs and 
grass at Liberia, Costa Rica. 
been actively maintained. The work con¬ 
sisted primarily of drainage, oiling, and 
spraying with Paris green where drainage 
was not practical. 
In the Republic of Nicaragua a coopera- 
