|Vander Meer, Robert - Bob|
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2011
Publication Date: 10/1/2011
Publication URL: http://handle.nal.usda.gov/10113/55790
Citation: Stringer, L.D., Suckling, D.M., Baird, D., Vander Meer, R.K., Christian, S.J., Lester, P.J. 2011. Sampling efficacy for the imported fire ant Solenopsis invicta (Hymenoptera: Formicidae). Environmental Entomology. 40(5):1276-1284. Interpretive Summary: The red imported fire ant, S. invicta, is among the world’s 100 worst invasive alien species. In the United States this ant species infests more than 320 million acres in 13 southern tier states and Puerto Rico and are spreading northward. It is estimated to be responsible for almost $7 billion annually in damage repair, medical care, and control costs. In the last decade S. invicta has changed from an invasive pest ant in the United States to a global problem, with infestations occurring in Australia, Taiwan, mainland China, Mexico and many Caribbean Island countries. The cost-effective detection of incipient invasive fire ant colonies before their establishment in new ranges is imperative for reducing their global impact and protection of national borders. In the present study, Scientists from the Imported Fire Ant and Household Insect Unit at the Center for Medical, Agricultural and Veterinary Entomology, USDA, ARS, Gainesville, FL, the New Zealand Institute for Plant & Food Research Limited, Christchurch, New Zealand, the Ministry of Agriculture and Forestry, Biosecurity New Zealand (MAFBNZ), Wellington, New Zealand, and Victoria University of Wellington, Wellington, New Zealand examined the sampling efficiency of food-baits, baited and un-baited pitfall traps in detecting isolated red imported fire ant nests in multiple environments in Gainesville, FL. This study produced an interactive spreadsheet that allows surveillance and incursion managers to estimate the probability of detecting specified or unknown S. invicta colony sizes. This model will support decision makers who need to balance the sampling cost and risk of failure to detect fire ant colonies.
Technical Abstract: The cost-effective detection of incipient invasive ant colonies before their establishment in new ranges is imperative for reducing their global impact and protection of national borders. We examined the sampling efficiency of food-baits, baited and un-baited pitfall traps in detecting isolated red imported fire ant, Solenopsis invicta Buren, nests in multiple environments in Gainesville, Florida. First, the bait preference of these ants was examined. Fire ants demonstrated a significantly higher preference for a mixed protein food type (hotdog or ground meat combined with sweet peanut butter). Second, we examined how nest size influences foraging distance for isolated monogyne (one queen) and polygyne (multiple queens) fire ant colonies in multiple environment types. Foraging distance success was a function of colony size, detection tool used, and duration of surveillance. The number of gynes in the colony did not influence detection success. Workers from small nests (0-15 cm mound diameter) traveled no more than 3 m to a food source, while large colonies (>30 cm mound diameter) traveled up to 17 m. Results from the study were used to create an interactive worksheet in Microsoft® Excel, whereby surveillance and incursion managers can alter tool type, density and duration parameters to estimate the probability of detecting specified or unknown S. invicta colony sizes. This model will support decision makers who need to balance the sampling cost and risk of failure to detect fire ant colonies.