[ Back to EurekAlert! ] Public release date: 8-Apr-2003
[ | E-mail | Share Share ]

Contact: Ben Ulph
bpl_jmkt_temp@oxon.blackwellpublishing.com
Blackwell Publishing Ltd.

Good housekeeping: why do shelter-dwelling caterpillars fling their frass?

Caterpillars of the silver-spotted skipper butterfly ballistically eject their individual fecal pellets (frass) as far as 40 body lengths away from their resting places in leaf shelters. Why do these and many other shelter-dwelling caterpillars go to such great lengths to distance themselves from their waste?

In a paper to appear in the April issue of Ecology Letters, M. Weiss shows that predatory wasps are attracted to skipper frass placed in leaf shelters, and that caterpillars in proximity to frass are particularly vulnerable to wasp predation. Caterpillars reared in close contact with accumulations of their own waste do not suffer ill effects; nor is repeated shelter-building, another possible consequence of frass accumulation, energetically expensive. Thus selection by natural enemies is likely to have been a driving force behind the evolution of frass ejection behavior in skipper caterpillars.

###


[ Back to EurekAlert! ] [ | E-mail | Share Share ]

 


AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.