The pseudosphinx tetrio, also known in some areas as the ‘Rasta caterpillar’ because of its bold colour pattern, has a voracious appetite.
Hordes of these charismatic caterpillars are stripping frangipani trees bare in some parts of Cayman, but why?
Cayman 27 took that question to the Department of Environment.
The pseudosphinx tetrio ambles its way down the stalk of a frangipani tree. Thanks to its bold colour pattern, it’s earned the nickname the ‘Rasta caterpillar.’
“You can’t miss them can you,” said DOE Terrestrial Resources Unit Manager Frederic Burton.
He said the says the pseudosphinx tetrio’s colours send a not-so-subtle message to would-be predators.
“It’s a warning coloration,” said Mr. Burton. “The idea is that the caterpillars are eating a plant that has toxins, which is the wild jasmine, or the frangipani tree, and it’s got all of these alkaloids in the sap. The caterpillars eat it and they are immune to it somehow or another and they’ve got all of this poison in their bodies.”
Mr. Burton told Cayman 27 while the pseudosphinx tetrio’s toxins protect it from most birds, the native blue iguana sees this native caterpillar as a tasty treat.
“They climb up the trees and they forget they are vegetarians for a day and just sit up there and eat these caterpillars,” said Mr. Burton.
Its powerful mandibles are perfect for slicing through its leafy diet, meaning these insatiable caterpillars can strip a tree bare to the branches.
But Mr. Burton told Cayman 27 it’s not as bad for the tree as it looks.
“As they do it the caterpillars are dropping all of the processed leaf in their droppings down right around the root zone so the plant just recycles all of that and puts it back up and does it all over, out come the new leaves and it doesn’t really seem to hurt the trees very seriously,” said Mr. Burton.
When its days of gluttony in the tress are behind it, the pseudosphinx tetrio begins its pupal stage on the ground in leaf litter, ultimately emerging to take flight as a hawk moth.
“Disappointingly in a way, the adult hawk moth is brown and grey,” said Mr. Burton. “It’s a big moth and it’s pretty remarkable, but it is not colorful like the caterpillars are.”
Mr. Burton said some with sensitive skin may find the ‘Rasta caterpillar’ slightly irritant if handled, however he warned strongly against ingesting this caterpillar.