Ecological Niche Modeling for the Prediction of Suitable Habitat for Chrysodeixis chalcites (Noctuidae) in the Contiguous United States

Abstract

Abstract The golden twin-spot moth, Chrysodeixis chalcites Esper (Lepidoptera: Noctuidae), is a polyphagous, polyvoltine crop pest occurring natively from northern Europe to Mediterranean Africa and the Canary Islands. Larvae feed on a wide variety of naturally occurring plants as well as soybean and other legume crops, short staple cotton, tomato, potato, peppers, tobacco, and banana. Chrysodeixis chalcites has been recorded in agricultural lands in the Ontario peninsula in eastern Canada and in northern counties of Indiana, USA. Given the strong potential for C. chalcites to invade USA crop lands, it is important to identify habitats most likely to sustain growing populations of this pest. Using occurrence data from its homerange, and environmental predictors including bioclimatic conditions, elevation, and human disturbance, we trained three ecological niche models, and used these models to estimate an ensemble prediction of habitat suitability in the contiguous US. Because human impact is potentially a confounding predictor, models were trained both with and without it. High habitat suitability was projected for the Atlantic coast from New England to Florida, the Gulf coast, the lower Midwest, and the Pacific coast and Central Valley of California. Though model predictions were robust, we recommend caution in their interpretation. First, agricultural lands are bioclimatically altered landscapes, and these alterations not reflected in bioclimatic data gathered from weather stations. Second, though the inclusion of human impact did not alter predictions on a large scale, it produced predictions favoring major metropolitan areas as suitable habitat, which we interpret as an artifact.