Toads beware: The next larva you eat could end up eating you. And not just eating you, but first sapping your precious bodily fluids, then devouring you alive.
Researchers Gil Wizen and Avital Gasith of Tel Aviv University already knew that adult Epomis beetles could spell trouble for toads and other amphibians. Discovery News reported on the Thunderdome-esque battles staged by the researchers between Epomis adults and a variety of amphibian species.
It looks like the larvae are chips off the old block. When the researchers placed larvae of two Epomis species (E. circumscriptus and E. dejeani) in the same containers as green toads (Pseudepidalea viridis) the larvae almost always emerged victorious.
The battles usually went like this:
After a larva and toad are placed together, the larva begins moving its mouth parts and antennae to attract the toad's attention. Toads and other amphibians regularly eat relatives of the Epomis larvae, so the toad thinks it has spotted a meal and begins creeping closer. The closer it gets, the more intensely the larva beckons.
The toad shoots out his tongue to snare the larva, but the Epomis jukes the tongue and lunges onto the unsuspecting toad. The larva then attaches itself using its mouth parts and begins the grisly and slow process of draining the toad of its juices, then gobbling away at the toad's flesh.
Sometimes the larva only gets a snack, and the traumatized toad manages to dislodge it, but not without receiving some serious wounds that leave nasty scars. But usually the toad ends up as larval lunch.
In one case, a toad actually managed to swallow a larva. The larva was then seen moving in the toad's stomach for another two hours, until it escaped from the amphibian's mouth. Then, in a macabre twist on Jonah and the Whale, the larva slew and devoured the toad that had swallowed it whole.
This table-turning behavior by the larva is very rare in nature. The authors note that it may have evolved as a defense mechanism, since Epomis beetles and their larvae live in the same habitats as amphibians. Many similar beetles fall prey to toads, frogs and salamanders. The Epomis species may have decided to fight back - and found a meal in the process.
The research was published in the journal PLoS ONE.
Although this larva may look like it's in trouble, it is actually attached to the toad's mouth and beginning to feed. (Gil Wizen)