YELLOW JACKETS (VESPULA-VULGARIS) AS A 2ND SEED DISPERSER FOR THE MYRMECOCHOROUS PLANT, TRILLIUM-OVATUM

Fleshy appendages attached to seeds (elaiosomes) can aid in seed dispe rsal by ants. This mode of dispersal (myrmecochory) occurs in over 300 0 species in 70 different plant families and is found on every contine nt except Antarctica. I have observed that a vespid wasp (the common y ellow jacket Vespula vulgaris) forages for the seeds of the elaiosome- bearing plant Trillium ovatum in Oregon and returns to the nest with s eeds and attached elaiosomes. Yellow jackets consume elaiosomes but no t seeds, thus this event represents effective seed dispersal. Upon inq uiry, it was learned that similar observations have been made for T-ov atum in California and the UK, for Vancouveria hexandra in Washington state. Given the ubiquity of yellow jackets, seed dispersal by yellow jackets (here termed ''vespicochory'') quite likely occurs in other el aiosome-bearing plants. Yellow jackets forage for much greater distanc es than ants, and therefore they will influence both the dispersal abi lity of plants and the genetic and demographic structure of population s.