Larvae of the lymantriid moth Eloria noyesi, which are obligate feeders on Eryrhroxylum Coca. excrete of the ingested cocaine as unchanged base. Cocaine, analysed by mass fragmentography, is readily detectable in the blood of larvae and is presumably sequestered during larval feeding, since it is present in the bodies of adult moths that do not feed on E. coca. Cocaine is an effective feeding deterrent for the ant Monomorium pharaonis when present in concentration below that found in the leaves of E. coca.