The Hawai`i-Pacific Islands Cooperative Ecosystems Studies Unit & Pacific Cooperative Studies Unit UNIVERSITY OF HAWAI`I AT MĀNOA Dr. David C. Duffy, Unit Leader Department of Botany 3190 Maile Way, St. John #408 Honolulu, Hawai’i 96822 Technical Report 186 A bioeconomic model of Little Fire Ant Wasmannia auropunctata in Hawaii December 2013 Michael Motoki1, Donna J. Lee1,2, Cas Vanderwoude3,4,5, Stuart T. Nakamoto6 and PingSun Leung1 1 Department of Natural Resources & Environmental Management, University of Hawaii 2 DJL Economic Consulting, Honolulu, Hawaii 3 Hawaii Department of Agriculture 4 The Hawaii Ant Lab, Hilo, Hawaii 5 The Pacific Cooperative Studies Unit, University of Hawaii 6 Department of Human Nutrition, Food & Animal Sciences, University of Hawaii PCSU is a cooperative program between the University of Hawai`i and U.S. National Park Service, Cooperative Ecological Studies Unit. Author Contact Information: Donna J. Lee, DJL Economic Consulting, Honolulu HI, DJL. [email protected]. Phone: 808.226- 9079 Recommended Citation: Motoki, M., D.J. Lee, C. Vanderwoude, S.T. Nakamoto and P.S. Leung. 2013. A bioeconomic model of Little Fire Ant Wasmannia auropunctata in Hawaii. Technical Report No. 186. Pacific Cooperative Studies Unit, University of Hawai`i, Honolulu, Hawai`i. 89 pp. Key words: Wasmannia auropunctata, bioeconomic modeling, invasive species, socio-economic impacts Place key words: Hawaii, Big Island, Kauai, Maui Editor: David C. Duffy, PCSU Unit Leader (Email: [email protected]) Series Editor: Clifford W. Morden, PCSU Deputy Director (Email: [email protected]) About this technical report series: This technical report series began in 1973 with the formation of the Cooperative National Park Resources Studies Unit at the University of Hawai'i at Mānoa. In 2000, it continued under the Pacific Cooperative Studies Unit (PCSU). The series currently is supported by the PCSU and the Hawai'i-Pacific Islands Cooperative Ecosystem Studies Unit (HPI CESU). The Pacific Cooperative Studies Unit at the University of Hawai'i at Mānoa works to protect cultural and natural biodiversity in the Pacific while encouraging a sustainable economy. PCSU works cooperatively with private, state and federal land management organizations, allowing them to pool and coordinate their efforts to address problems across the landscape. The Hawaii-Pacific Islands Cooperative Ecosystem Studies Unit is a coalition of governmental agencies, non-governmental organizations and universities that promotes research, education and technical assistance to support better stewardship of imperiled natural and cultural resources within the Pacific. The HPI CESU is one of 17 cooperative ecosystem studies units across the U.S. A Bioeconomic Model of Little Fire Ant Wasmannia auropunctata in Hawaii Authors Michael Motoki1, Donna J. Lee1,2, Cas Vanderwoude3, Stuart T. Nakamoto4, and PingSun Leung1 1Department of Natural Resources & Environmental Management, University of Hawaii 2DJL Economic Consulting 3Hawaii Department of Agriculture 4Department of Human Nutrition, Food & Animal Sciences, University of Hawaii Contact Donna J. Lee, DJL Economic Consulting, Honolulu HI, [email protected]. 808.226-9079 Abstract Wasmannia auropunctata, known as the Little Fire Ant (LFA), was first detected on the island of Hawai‘i (the Big Island) in 1999. It was most probably introduced through imports of contaminated potted plants from mainland USA. We estimate that LFA has now spread to over 4,000 locations on the Big Island and under current management efforts will spread rapidly inundating the Big Island in 15-20 years. Increased efforts in prevention, detections, and mitigation treatments will suppress existing infestations, reduce rate of spread and decrease long term management costs, damages, and human stings. Benefits from increased management are estimated to be $5 billion savings including $540 million in reduced damages and 2.1 billion fewer sting incidents over 35 years. Keywords: bioeconomic modeling, invasive species, socio-economic impacts December 2013 Contents Introduction ........................................................................................................................................................... 1 Problem statement ............................................................................................................................................ 1 Research purpose............................................................................................................................................... 1 Research method ............................................................................................................................................... 1 Roadmap ........................................................................................................................................................... 1 Background ............................................................................................................................................................ 1 Introduced ant species ....................................................................................................................................... 1 Distribution ........................................................................................................................................................ 2 Hawaiian Islands ............................................................................................................................................ 3 Native range and worldwide distribution ........................................................................................................ 5 Biology and ecology ........................................................................................................................................... 5 Reproduction ................................................................................................................................................. 6 Density .......................................................................................................................................................... 7 Invasive traits ................................................................................................................................................. 7 LFA management on the Big Island ................................................................................................................... 11 Historical management ................................................................................................................................ 11 Current management ................................................................................................................................... 12 Previous work ...................................................................................................................................................... 15 Modeling ant growth and dispersal .................................................................................................................. 15 Modeling growth ......................................................................................................................................... 15 Modeling short distance dispersal ................................................................................................................ 15 Modeling long distance dispersal ................................................................................................................. 15 Modeling invasive species management ........................................................................................................... 16 Types of models ........................................................................................................................................... 16 Types of management .................................................................................................................................. 17 Cost of management .................................................................................................................................... 18 Modeling invasive species impact ................................................................................................................. 18 LFA Bioeconomic Model ....................................................................................................................................... 19 Model overview ............................................................................................................................................... 19 Model scope .................................................................................................................................................... 20 Management submodel ................................................................................................................................... 20 Prevention ................................................................................................................................................... 21 Detection ..................................................................................................................................................... 21 Mitigation .................................................................................................................................................... 22 Biological submodel ........................................................................................................................................