Household and Structural Insects Reinvasion Dynamics of Subterranean Termites (Isoptera: Rhinotermitidae) Following the Elimination of All Detectable Colonies in a Large Area Nan-Yao Su, 1,2 Eric Guidry, 3 Aaron J. Mullins, 1 and Carrie Cotonne 3 1 Department of Entomology and Nematology, Ft. Lauderdale Research and Education Center, University of Florida, Institute of Food and Agricultural Sciences, 3205 College Ave., Ft. Lauderdale, FL 33314 (nysu@ufl.edu; amull81@ufl.edu), 2 Corresponding author, e-mail: nysu@ufl.edu, and 3 New Orleans Mosquito and Termite Control Board, 6601 Stars and Stripes Blvd., New Orleans, LA 70124 (eguidrynola@gmail.com; cbowens@nola.gov) Received 12 November 2015; Accepted 16 January 2016 Abstract Following the elimination of all detectable termite colonies in the 32-acre Louis Armstrong Park in New Orleans, LA, in 2002–2003, termite activity was monitored by using 808 Sentricon stations. Between January 2004 and July 2005, termites were found in 8–11 stations. In August 2005, the Park was flooded by Hurricane Katrina, but termites remained active. Post-Katrina termite activity levels of 16–21 stations were recorded throughout 2006, and in October 2007, the activity drastically increased to 43 stations. This rapid increase of termite activity continued into 2008, and a total of 94 stations harbored termite activities by July 2008. Termite activity peaked at 109 stations in September 2008 and then leveled down to 64 stations in March 2009. Termite activity in the Park between 2004 and 2009 was described by a Sigmoid model with a carrying capacity of 76 stations, and a Sigmoid mid-point of 1,202 d. In April 2009, a total of 14 colonies of Coptotermes formosanus Shiraki and one colony of Reticulitermes flavipes (Kollar) were delineated by using microsatellite genotyping and mark–recapture protocol. Of the 15 colo- nies, eight near the Park border probably originated from existing colonies from outside, and seven C. formosanus colonies found inside the Park were probably initiated by alate pairs. Our results showed that, if surrounded by high population pressure of termites and no control measures are applied, an area cleared of termite populations by baits can be completely re-populated by termites from outside in 53 mo. Key words: Formosan subterranean termite, eastern subterranean termite, termite bait, reinvasion, area-wide management The Formosan subterranean termite, Coptotermes formosanus Shiraki, is one of the most economically important termite pests in the world (Rust and Su 2012). Due to its destructive potential and wide-spread distribution, C. formosanus is responsible for a large por- tion of the US$40 billion annual economic impact by termite pests. In the continental United States, C. formosanus was first reported from Louisiana, Texas, and South Carolina in the 1960s, and has become well established in most of the southeastern United States (Su and Scheffrahn 2013). In New Orleans, LA, C. formosanus infestation started in Camp Leroy Johnson on Lake Pontchartrain and Naval Shipyards in Algiers (Spink 1967), and has since spread to the entire metropolitan area. Irreversible damage to historic buildings in the French Quarter (Su et al. 2000) and termites’ impact on tourism have been the public concern, and in 1998 a federally funded project, Operation Full Stop, was launched for research and control of C. formosanus under the auspice of the USDA/ARS (Guillot et al. 2010). The main project of the Operation was the area-wide popula- tion management of C. formosanus in French Quarter, New Orleans. In support of the French Quarter project, another project was initiated to study the population dynamics of C. formosanus colonies in the adjacent Louis Armstrong Park, with the emphasis on the response of termite colonies to population management tactics such as bait applications. The Armstrong Park project began with the identification of 13 C. formosanus colonies in 1998 in the 32-acre area by using mark–recapture protocol (Messenger 2003), and genotyping techni- ques (Husseneder et al. 2003). Termite activity of these 13 colonies was monitored monthly or bimonthly until 2001 when three colo- nies were selected for elimination by using the Sentricon Colony Elimination System (Dow AgroSciences LLC, Indianapolis, IN) with 0.5% hexaflumuron baits (Messenger et al. 2005). Results of the selective elimination study showed that in an area of high popula- tion pressure of subterranean termites, territories of eliminated colo- nies could be re-occupied by neighboring termite populations in a matter of days. After the selective elimination study, hexaflumuron and noviflumuron baits were applied to all detectable colonies of subterranean termites in the Park, and by July 2003 all baited colo- nies were eliminated (Mullins et al. 2011). From September 2003 to V C The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com 1 Journal of Economic Entomology, 2016, 1–6 doi: 10.1093/jee/tow018 Research article Journal of Economic Entomology Advance Access published February 18, 2016 at Don Thomson on March 23, 2016 http://jee.oxfordjournals.org/ Downloaded from