American chestnut [Castanea dentate (Marshall) Borkhausen, Fagales: Fagaceae] was a dominant forest tree in the eastern forests of the U.S. until it was eliminated as a canopy tree species by 2 exotic pathogens. Ink disease, a root rot caused by Phytophthora cinnamomi Rands (Pythiales: Pythiaceae), began to destroy chestnut populations on bottomland and poorly-drained sites in the mid-1800s, and the chestnut blight fungus [Cryphonectria parasitica (Murrill) Barr, Diaporthales: Cryphonectriaceae] reduced the species to short-lived sprouts on upland sites in the first half of the 20th Century (cf. Campbell and Schlarbaum 2002, Fading Forests II: Trading Away North America’s Heritage, healing Stones Found., Knoxville, TN). Various organizations have used a backcross breeding approach to integrate blight resistance from Asiatic chestnut species into American chestnut in an effort to restore the species to eastern forests (Anagnostakis 1999, In Proc. 2nd Intern Symp. Chestnut; Hebard 2001, Ecol. Restor. 19: 252-254). Putatively blight-resistant hybrid chestnuts became available for planting in 2008 (Clark et al. 2010, In Proc. 17th Central Hardwoods Forest Conf.).
Pinchot, Cornelia C.; Schlarbaum, Scott E.; Saxton, Arnold M.; Clark, Stacy L.; Schweitzer, Callie J.; Smith, David R.; Mangini, Alex.; Hebard, Frederick V. 2011. Incidence of Craesus castaneae (Hymenoptera: Tenthredinidae) on Chestnut Seedlings Planted in the Daniel Boone National Forest, Kentucky. Journal of Entomological Science 46(3):265-268.