A question for plant ecologists and others interested in pollination vectors: How does one establish that an insect species found "hanging around" a particular species of flower in bloom is in fact a pollination vector for that plant species? At the moment I'm interested in some speciation questions regarding Trillium in the Great Smoky Mountains National Park and vicinity. One question I want to look into is if there are differences in pollination vectors that might serve to help isolate two sympatric species to some extent? At the moment, two of us have photographed what appear to be Drosophila (fruit flies) sitting on flowers of Trillium. Where do we go from here to try to establish cause and effect? Jim Shields in very rainy central Indiana (USA) ************************************************* Jim Shields USDA Zone 5 Shields Gardens, Ltd. P.O. Box 92 WWW: http://www.shieldsgardens.com/ Westfield, Indiana 46074, USA Tel. ++1-317-867-3344 or toll-free 1-866-449-3344 in USA