“A Tale of Two Pests: The Implications of Introduced Pest Insects in Agriculture”
In the United States, introduced species were responsible for about $120 billion worth of environmental damages and economic losses annually. Of these losses and damages, arthropod pests of agricultural crops were estimated to cause over 10% alone, in 2004. In this presentation, two introduced insect pests of agriculture will be discussed. The sugarcane aphid, Melanaphis sacchari Zehntner, was introduced to Florida and Louisiana sugarcane beginning in the 1970’s. However, in 2013 it emerged as a devastating pest of sorghum in the southern United States and has since spread to over 20 states, causing yield losses wherever it is found. Interestingly, prior to this host switching event sugarcane aphid has never caused economic losses and very rarely required management. Reasons for sugarcane aphid feeding on sorghum are largely unknown; it is possible that a new biotype has evolved from populations already present on sugarcane, or that sugarcane aphid acquired novel bacterial endosymbionts that allow it to consume a new diet. Similar to sugarcane aphid, the Asiatic garden beetle, Maladera castanea (Arrow), has been present in eastern United States since the 1920’s, largely as a minor pest of turf and ornamentals, yet has recently emerged as an early season pest of field corn and soybean from 2008-2012 in Northwestern Ohio, Southern Michigan, and Northern Indiana. Little information is currently available regarding the population genetics of Asiatic garden beetle, or the management of this pest in field crops. Current efforts are being focused on evaluating sampling methods in field corn for future studies. The underlying mechanisms responsible for the sugarcane aphid’s host switch will be presented, while current knowledge and future directions for Asiatic garden beetle research and management in field crops will be discussed.
Adrian Pekarcik is a Ph.D. Student with the Department of Entomology at The Ohio State University.