The Parasite Moniliformis moniliformis Alters the Escape Response of its Cockroach Host Periplaneta americana

The immature stages of some parasites live in prey animals (intermediate hosts) and only reach reproductive maturity when they are eaten by final host predators. Some of these parasites alter intermediate host behavior in ways that increase the likelihood of predation (parasite transmission). Using the acanthocephalan (Moniliformis moniliformis) in the cockroach (Periplaneta americana), we show that infected cockroaches experienced a decrease in wind-evoked escape responses, a predator avoidance behavior, that consisted of fewer escape responses, longer latency and higher threshold for escape behavior. We found no correlates of the impairment of the escape behavior in the abdominal portion of the escape neuronal circuitry. This study demonstrates a parasite-induced alteration of a behavior dedicated to predator avoidance.