Bamboo,
at least ¾- to 1-inch inner diameter, can be used for refugia
traps (provides retreat and nesting site) for coqui frogs.
Cut the bamboo between nodes (8-10 inches in length), to make
a cylinder with one open end. Drill a 1-inch hole along the
side, about 4 inches from the closed end (Fig. 1). The hole
will serve as an entrance to the trap. Use black plastic to
partially cover the open end of the bamboo cylinder to provide
some protection for the frogs seeking refuge while allowing
rain to collect in the trap, making it more attractive to
the frog. The traps should be attached 3 to 5 ft above the
ground on trees or stakes in infested areas (where frogs are
calling). According to Dr Larry Woolbright, an expert with
coqui frogs, these traps can be preferred refuge sites or
homes for the frogs.
Figure
1. Bamboo refugia
PVC
(polyvinyl chloride) pipe, ¾ to 1-inch diameter, can also
be used to make refugia traps for coqui frogs. Field trials
indicate that the frogs prefer PVC to bamboo. A Tee-joint
at the top of a straight piece (about 8 inches long) makes
it even more attractive to the frogs (Fig. 2). As with the
bamboo traps, affix the PVC trap about 3
to 5 ft above the ground. The
traps are more effective after weathering by exposure to
the sun and rain to dissipate the PVC odor. Trap
efficiency in tests at Lava Tree State park has been 28
to 30%.
Figure
2. PVC pipe refugia
 
Although
the frogs can freely come and go from the trap, they rarely
try to escape and can be easily captured. Check the traps
during the day at least every 2 weeks (eggs hatch in 14 days)
(Fig. 3); remove any adults and eggs you find into a plastic
bag or similar container and apply any one of the following
treatments: 1) fill the container with hot, soapy water (at
least 113 o F for 3 min.), 2) freeze for at least 3 hours,
or 3) thoroughly spray eggs and adults with 16% citric acid
solution (1.3 lb citric acid per 1 gallon of water, or use
premixed solutions available in garden shops). Make sure the
frogs are dead before disposal to avoid accidentally infesting
dump sites.
Figure
3. PVC refugia with brooding adult males and eggs
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