Pathways of non-indigenous plant pest introductions: How exotic insects, pathogens and weeds arrive in the United States

Non-indigenous weeds, phytophagous insects and plant pathogens have had dramatic effects on ecosystems in North America and threaten nearly half of all endangered species in the United States. Introductions of non-indigenous species are expected to continue and will likely increase as global trade expands. The U.S. Department of Agriculture, Animal and Plant Health Inspection Service (USDA, APHIS) is responsible for excluding non-indigenous phytophagous insects, plant pathogens and noxious weeds. Since 1985, APHIS personnel have maintained a database of non-indigenous species detected at ports, border inspection stations and airports. This database, known as the Port Interception Network or "PIN" data, exists on an aging mainframe computer in Maryland. Over 50,000 reports are entered into the PIN database annually. The PIN database, which has not been made available to the public, is unwieldy and queries must be carefully designed to extract appropriate data. APHIS personnel have used the PIN data for internal assessments and training, but intensive and multidisciplinary analysis of these data has not been attempted. Detailed and intensive analysis of the entire PIN database will greatly increase our understanding of precisely how unwanted organisms are entering the United States. In addition, results of our pathway analysis coupled with literature reviews should enable us to evaluate potential patterns or attributes of successful invaders. An interdisciplinary team of entomologists, pathologists, and botanists will analyze the PIN database. Our objectives are to: 1. Summarize historical trends in the groups of plant-feeding insects and related arthropods, plant pathogens and undesirable plants that arrive at the borders of the U.S.; 2. Evaluate potential associations or patterns that involve taxa from two or more groups; e.g. determine whether plant species or commodities are consistently associated with specific arthropod or pathogen introductions; 3. Identify the frequency that specific guilds or taxa arrive and the rate of establishment of members of those groups; 4. Determine whether attributes such as host breadth, size of native range, reproductive rate, mating system, dispersal method or other traits are related to the frequency of introduction or establishment of selected taxa.