Two formicarial ant-plants endemic to Panama and adjacent areas of Costa Rica co-occur in mid-elevation cloud forest yet have distinctive modifications to house and feed small, retiring ants. Besleria formicaria (Gesneriaceae) hosts only Pheidole sp. which harvest the oil-rich seeds of its host and other plants and insect parts. Hoffmannia vesciculifera (Rubiaceae) hosts only Solenopsis sp. ants which obtain lipid and possibly other nutrients from vescicular tissues. Judging by their abundance in refuse deposits, fern sporangia appear to be a plentiful and evenly distributed resource exploited by both ant species.
