Recently there was a program on NPR that discussed bindweed mites, a biological control agent of field bindweed and some of its relatives. I found some background information for you on the internet that discusses their biology and also about a distribution program that Adams County is doing in July. You may want to refer folks to this information.
http://www.colostate.edu/Dept/CoopExt/Adams/weed/bindweed_mite.html
The main points to keep in mind about the mites is that they don't perform well in irrigated sites (i.e. irrigated lawns) and it takes a few years for them to successfully control the bindweed. According to Tony Koski, CSU Extension Turf Garss Specialist, a product that contains Quinclorac (i.e., Ortho's Weed B Gone Max plus crabgrass control) does a really good job of bindweed control in home lawns. Spot treat only.
Mary
