PHOTO COURTESY OF MARY ANN FRAZIER
Cornell University has a new publication called Wild Pollinators of Eastern Apple Orchards and How to Conserve Them, compiled by Cornell’s Mia Park with seven coauthors from Cornell, Penn State, and the Xerces Society.
The 20-page publication describes the habits of major wild bee species (more than 80 species pollinate fruit crops in the eastern United States). The five most important are small mining bees, hornfaced bees (often called orchard bees or mason bees), blue-green sweat bees, large mining bees, and bumblebees.
Many of them, the publication reminds growers, are much more effective pollinators than honeybees, so a few can go a long way.
The bees are classified as ground nesters, cavity nesters (like bumblebees), and tunnel nesters. Many of these bees don’t build their nests from scratch, but use existing cavities like rodent holes and plant stems. Carpenter bees, which tunnel into structural wood and are sometimes considered pests, are rated as effective apple pollinators. Part of the publication is devoted to advice on creating and conserving nesting sites.
These bees are in the apple orchards at bloom time, but need alternative sources of food both during and after the apple bloom. Part of the booklet is devoted to the planting or encouragement of forage plants.
A short section addresses pesticides and their toxicity levels to bees. Paraquat was cited as toxic to ground-dwelling bees and glyphosate as less so.
The publication can be downloaded at www.northeastipm.org/park2012.