The pictures are of what we thought were caterpillars eating Florida Slash Pine. According to Mary Misitis in her Plant Clinic article in the Miami Herald (May 2), instead of a caterpillar, this may be the larvae of a wasp!

Caterpillars normally eat specific plants.  The caterpillars are hatched from eggs laid by butterflies or moths.  After the caterpillar has eaten as much as it can or as much as is available, the caterpillar weaves a cocoon around itself.  Soon there is a chemical change inside the cocoon.  You can actually see the cocoon's movement, as if something was cooking inside it.  After awhile, the cocoon is ripped open and a new butterfly or moth is born.  The butterfly or moth will eat nectar from plants that are normally different than the ones eaten by their caterpillars.

If Mary Misitis is right, the nonstinging wasp is called a Red Headed Pine Sawfly. The larvae eat the needle down to just before the trunk; therefore, the tree is probably not really hurt.  The tree infested with the caterpillars was pretty well eaten on one side, but the tree is under five years old and not over 10'. According to the Plant Clinic article, a second infestation could kill the tree. Control is as simple as picking off the larvae.

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