46 MARCH 2024 • WORLD AQUACULTURE • WWW.WAS.ORG Across the southeastern United States, a large invasive snail threatens the sustainability of crawfish and rice production. This species of apple snail, Pomacea maculata, known by multiple (although not very useful) common names including “spotted apple snail,” “giant apple snail,” and “island apple snail” originates in South America, but has spread widely across Southeast and East Asia and Europe (Spain). The snail is a popular aquarium pet, resulting in transport to new areas through the pet trade. The snail’s life history and physiology facilitate its success as a highly invasive species. For example, this aquatic pest is amphibious, making it able to evade predators and survive harsh environmental conditions. It is also highly fecund, laying approximately 2,000 eggs per clutch. This high reproduction capacity, paired with a long lifespan, results in many generations over multiple years. Throughout most of the invaded range, P. maculata is considered a pest, particularly within agriculture. In Asia, Europe, and the southeastern U.S. invasive apple snails cause substantial losses in the rice industry. In Hawaii, the related species, Pomacea canaliculata was introduced, becoming the most important pest of taro, a major agricultural commodity in the islands. This species can also be found in other U.S. states, including California, Arizona, and Florida. Recently, P. maculata began to adversely affect the crawfish industry of the southeastern U.S. In this region, particularly in Louisiana, rice and crawfish are cultivated simultaneously in the same fields, and thus both commodities are vulnerable to this invasion. Apple snails, with their large size and strong appetite, commonly block the openings of crawfish traps, reducing catch rates and resulting in economic losses to the industry. Additionally, if an apple snail successfully enters a trap, it must be manually separated from the crawfish before they can be sent to market, thereby increasing labor costs. While changes in cultivation practices have helped to mitigate the apple snails’ impact on rice production, the crawfish industry also needs specific management strategies to minimize economic losses. In February 2023, the Agricultural Research Service (USDA-ARS) and the Animal and Plant Health Inspection Service (USDAAPHIS) co-hosted a virtual workshop to highlight current knowledge, past research, and future management strategies for P. maculata. The virtual workshop brought together research scientists, farmers, state and federal agencies, nongovernmental organizations (NGOs), university personnel, policy makers, schoolteachers, and other members of the public. More than 50 individuals registered for the workshop, and more than 120 attendees participated across the three weekly meetings. During each of the 2-hour meetings, presentations from invited scientists highlighted one of three broad Apple Snails: Discussions of Past Problems and Future Solutions for an Emerging Pest in United States Agriculture/Aquaculture Bradley M. Richardson, Robert H. Cowie, Blake E. Wilson, Kenneth A. Hayes, James E. Byers, Jiangxiao Qiu, T. Graham Rosser, Charles C. Mischke, Romi L. Burks, Julian M. Lucero, Amy L. Roda FIGURE 1. Apple snail depositing eggs on a wooden piling in Houston, TX. Photograph used with permission from Lauren Muskara Across the southeastern United States, a large invasive snail threatens the sustainability of crawfish and rice production. This species of apple snail, Pomacea maculata, known by multiple (although not very useful) common names including “spotted apple snail,” “giant apple snail,” and “island apple snail” originates in South America, but has spread widely across Southeast and East Asia and Europe (Spain). The snail is a popular aquarium pet, resulting in transport to new areas through the pet trade. The snail’s life history and physiology facilitate its success as a highly invasive species.
RkJQdWJsaXNoZXIy MjExNDY=