Dave was born in 1956 in Oakland, California. He was raised in California, Oregon, and Pennsylvania, but it was his uncle and aunt's farm in the Ozarks that catalyzed much of his early interest in Lepidoptera, reptiles, and natural history. He obtained his BS from Colorado State University in plant pathology and botany and Ph.D. in entomology working under Jerry Powell at the University of California, Berkeley. From there, he went to the California Academy of Natural Sciences (San Francisco) and the University of Vermont for one-year post-docs, before accepting a faculty position in the Ecology & Evolutionary Biology Department at the University of Connecticut. He has traveled (and collected) extensively in Costa Rica and Ecuador.
His research interests include the biosystematics of ghost moths (Hepialidae), several families of leafminers, and Noctuidae. Over the past decade Wagner has taken a special interest in the immature stages and life histories of Macrolepidoptera, publishing three books and several peer-reviewed journal articles on caterpillars. He is nearing completion of a volume treating 800 species of eastern owlets (Noctuoidea). Several of Dave's recent papers have focused on the systematic value of larvae in revealing phylogenetic associations.
Wagner has a deep interest in matters relating to insect conservation. He chairs the Connecticut's Advisory Panel for rare and endangered insects and other invertebrates and is frequently called upon by governmental agencies and NGOs for his advice on the Northeast's imperiled insect biota. He was been an active member of The Lepidopterists' Society's Conservation Committee. Together with Larry Gall and Jane O'Donnell, Wagner recently completed work on a butterfly atlas for the state of Connecticut and a review article on threats posed to rare or endangered insects by non-native species. His book with Dale Schweitzer and Marc Minno on Rare, Declining, and Poorly Known Butterflies and Moths (Lepidoptera) of Forests and Woodlands in the Eastern United States is due out in late 2010.
In addition to serving on the Wedge Foundation Board since 2002, Wagner was vice-chair for the "All Taxa Biodiversity Inventory" in Great Smoky Mountains National Park, is serving on the board for the Connecticut State Museum of Natural History, is a Delegate for the Organization for Tropical Studies, and is Co-Director of the University of Connecticut's Center for Conservation and Biodiversity.
Presently he is living in Storrs, Connecticut. Pastimes include fishing, bicycling, and volleyball, and he enjoys bird watching, travel, and gardening with his wife Sylvia. His eldest child, Virginia, is earning her Master of Fine Arts at MICA in Baltimore, and his son Ryan, is studying biology and biochemistry at Wake Forest University.