43 The Ohio State University/Ohio Agricultural Research and Development Center ~ 7 ~ Insect and Mite Activity Noted in Ohio Nurseries and Landscapes: 2004 Joseph F. Boggs, Barbara Bloetscher, David J. Shetlar, Curtis E. Young, Amy K. Stone, Pamela J. Bennett, Erik A. Draper, David J. Goerig, Timothy J. Malinich, David E. Dyke, and James A. Chatfield Introduction Insect and mite activities reported in 2004 in Ohio State University Extension’s Buckeye Yard and Garden Line (BYGL) and Pest Evaluation and Suppression Techniques (PEST) newsletters as well as other sources are summarized and compared to previous seasons. Unusual insect and mite activity is also reported. Summary Caterpillars that produce general defoliation were conspicuous by their relative absence in Ohio landscapes during the 2004 season. These included gypsy moth (Lymantria dispar); yellownecked caterpillar (Datana ministra); and walnut caterpillar (D. integerrima). However, giant silkworm moths were commonly noticed, including hickory horned devil (Citheronia regalis); polyphemus moth (Antheraea polyphemus); cecropia moth (Hyalophora cecropia); promethia moth (Callosamia promethea); and imperial moth (Eacles imperialis). High populations of grasshoppers were observed in western Ohio, but heavy infections of the fungal insect pathogen, Entomophaga grylli, were also observed. A number of sawfly defoliators made their presence known, including dusky birch sawfly (Croesus latitarsus); European pine sawfly (Neodiprion sertifer); redheaded pine sawfly (Neodiprion lecontei); introduced pine sawfly (N. similis); and white pine sawfly (N. pinetum). The common bagworm (Thyridopteryx ephemeraeformis) appeared in high numbers in the southern and central parts of Ohio, with few damaging populations found in the northern part of the state. Mimosa webworm (Homadaula anisocentra) populations were heavy in central and northeastern Ohio. Localized high populations of forest tent caterpillars (Malacosoma disstria) occurred in southwestern Ohio, but eastern tent caterpillar (Malacosoma americanum) and fall webworm (Hyphantria cunea) were virtual “no-shows” in much of the state. Joseph F. Boggs, Ohio State University Extension, Hamilton County, OSU Extension Center at Piketon; Barbara Bloetscher, Ohio State University Extension, C. Wayne Ellett Plant and Pest Diagnostic Clinic, Entomology; David J. Shetlar, Ohio State University Extension, Ohio Agriculture Research and Development Center, Entomology; Curtis E. Young, Ohio State University Extension, Allen County; Amy K. Stone, Ohio State University Extension, Lucas County; Pamela J. Bennett, Ohio State University Extension, Clark County; Erik A. Draper, Ohio State University Extension, Geauga County; David J. Goerig, Ohio State University Extension, Mahoning County; Timothy J. Malinich, Ohio State University Extension, Cuyahoga County; David E. Dyke, Ohio State University Extension, Hamilton County; and James A. Chatfield, Ohio State University Extension Center at Wooster, Horticulture and Crop Science.