We posted recently our first thoughts regarding mangrove die-off in
The Marls (see here and here). After the visit, we got some feedback
from mangrove herbivory expert Ilka C. Feller – see her email after the
jump. She speculates something we also did before our recent visit.
There are several species of Lepidoptera residents in the mangroves including the mangrove skipper, a very lovely little butterfly. Phocides has very distinctive larvae with even more distinctive behavior and feeding patterns. There are some moths as well, but they should be readily identifiable even based on leaf damage patterns. Some of the damage on the leaves in the photographs in the website you sent look like they could have been made by the mangrove tree crab Aratus pisonii.
There are documented outbreaks of Phocides pigmalion in mangroves. But, that dieback of the mangrove site in Abaco does not look like an insect outbreak. With that extent of dead trees, you should look for abiotic causes, e.g., changes in hydrology, sedimentation, etc. Are there any development activities in the area that have changed the flow of water into or out of this site? Phocides eats leaves only; it does not eat the buds or kill the trees. Something else is going on at that site
Ilka C. Feller
Smithsonian Environmental Research Center
647 Contees Wharf Rd.
Edgewater MD 21037