Ants and Lycaenid Caterpillars
The larvae (caterpillars) of lycaenids that participate in a mutualism
with ants have evolved several ways to communicate with the ants:
- many of these caterpillars can produce sound
(stridulations, squeaks, grunts) that also help them communicate with
ants. These sounds are not always audible to human ears, but are transmitted
to the ant through the plant the caterpillar and ant are both on.
- the pore cupolas--glands scattered
over the surface of the caterpillar--are thought to alert the ants to
the fact that the caterpillar is not a prey item (perhaps through chemical
- the dorsal nectary organ (DNO)
is a specialized gland that secretes a nectar-like substance.
- the tentacular organs (TOs), two
eversible structures, also seem to function in ant-caterpillar communications.
Above: ant drinking from the nectary organ
of a lycaenid larva.
Next: What it looks like when the
lycaenid extrudes the TOs.
Drawing of enlarged tentacular organ based, with permission,
on the SEM photographs of Roger Kitching, as published in the book The
Ants, by Holldobler and Wilson (pub info).