Forest Tent Caterpillar Moth - Toxicity

Toxicity

A closely related species, the eastern tent caterpillar (Malacosoma americanum), has been linked to a phenomenon called 'Mare Reproductive Loss Syndrome' (MRLS). Experimental studies have shown that when pregnant mares are fed eastern tent caterpillars they abort. The caterpillars of this species often feed on the highly cyanogenic black cherry tree (Prunus serotina) and it was originally hypothesized that the mares were aborting in response to the cyanide they consumed along with the caterpillars. However, that hypothesis was disproven. In another study, the necropsy of a mare fed eastern tent caterpillars showed that fragments of the caterpillar's setae had embedded in the gut wall leading investigators to hypothesize that these invasive fragments may allow infective agents to pass into the animal's blood stream then travel to the placenta, initiating an abortive event. It remains to be determined whether this is indeed the cause of MRLS.