Biology, Identification, and History of the Light Brown Apple Moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae: Archipini) in California: An Example of the Importance of Local Faunal Surveys to Document the Establishment of Exotic Insects

Abstract

The light brown apple moth (LBAM), Epiphyas postvittana (Walker), is a polyphagous species that is an important pest of apple, citrus, and grapes in Australia and New Zealand. The potential threat of LBAM to U.S. agriculture was recognized formally in 1957 when this species was included in the pest alert series Insects Not Known to Occur in the United of the Cooperative Economic Insect Report. Although LBAM was excluded from a list of the top 100 most dangerous exotic pests of concern to the United States in 1973, most regulatory entomologists have continued to cite this species in risk assessments. LBAM was first discovered in the United States at Berkeley, CA, in 2006. Pheromone trapping efforts in 2007–2009 by the California Department of Food and Agriculture and the U.S. Department of Agriculture revealed its presence in Alameda, Contra Costa, Los Angeles, Marin, Monterey, Napa, San Benito, San Francisco, San Joaquin, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Solano, Sonoma, Ventura, and Yolo counties, California. Previous surveys in California over the past 40 years, for LBAM in particular and for Lepidoptera in general, covering a variety of habitats including most of the known geographical range of LBAM, failed to detect this species. These negative data provide circumstantial evidence that LBAM arrived in California only recently. We provide descriptions and illustrations to help identify this newly arrived pest, along with a history of its discovery.