Pygidial secretions of Pasimachus subsulcatus (Coleoptera: Carabidae) deter predation by Eumeces inexpectatus (Squamata: Scincidae)

The carabid beetle Pasimachus subsulcatus is an abundant ground-dwelling insect in west central Florida that exudes a powerful mucous membrane irritant when disturbed. The southeastern five-lined skink, Eumeces inexpectatus , is an abundant insectivorous lizard sympatric with Pasimachus . Analysis of Eumeces gut contents and field feeding trials indicate that Pasimachus are not ingested by the lizard, yet arthropods of comparable size and exoskeletal thickness are ingested. Eumeces are consistently repelled by Pasimachus secretion constituents, indicating that the beetle is protected chemically from the lizard.