Linda Benedict | 4/10/2006 9:23:13 PM
Dennis R. Ring, Alan L. Morgan, Frank S. Guillot, Alan R. Lax and Debbie L. Boykin
The Formosan subterranean termite is a devastating pest that consumes wooden structures and woody plants. Hundreds of millions of dollars are lost each year because of damage caused by this insect and the cost of managing it.
An integrated pest management program called the French Quarter Program is being conducted in New Orleans as a part of Operation Full Stop, a nationwide termite management program. Its focus is a community-based management strategy to reduce the densities of Formosan subterranean termites. The program is a cooperative effort with the U.S. Department of Agriculture and the New Orleans Mosquito and Termite Control Board.
The federally funded program pays the pest control applicators, so homeowners have no out-of-pocket expense for the treatments. Although hurricanes Katrina and Rita interrupted the project, the French Quarter had little flooding, and the research is continuing.
The program began in 1998, and individual buildings were treated with commercially available baits or nonrepellent termiticides in three stages. The first area treated (Area 1) was a 15-square-block area in the heart of the French Quarter. See the map. In 2002, the program added 20 square blocks (Area 2) that surround Area 1. Treatment of a third area (Area 3) began in March 2004 and included an additional 20 square blocks.
Two additional areas in the French Quarter – Area 4 by the Mississippi River with no structures on it and Area 5, the remainder of the French Quarter – are not yet in the program.
All of the properties in Area 1 were treated within two years after the program began, and 90 percent of the properties in Areas 2 and 3 were under contract and treated as of January 2005. When all properties in these three areas are under contract, approximately 56 square blocks will be covered by areawide management. In addition, about 40 percent of the properties in Area 5 are receiving some termite control as a result of private contracts with commercial pesticide operators. Eventually, the program will include areas 4 and 5 under areawide management.
Formosan subterranean termites expand their territories naturally by producing winged “alates” that swarm each spring. To measure effectiveness of the program, the research team sets up alate traps during the swarming season in late spring and early summer. Alate numbers were sampled using sticky traps placed on light poles in 46 locations in the French Quarter in 1998 and 1999. One sticky trap was put on every corner of the 15-block test area (24 corners). Additional traps (20) were spaced throughout the French Quarter. Beginning in 2000, alate numbers were sampled throughout the entire French Quarter by placing sticky traps at each intersection.
Along with monitoring alates, 12 in-ground monitoring stations were put around each square block in Area 1. Holes were drilled through the sidewalks at regular intervals of approximately 25 yards throughout the treatment zone, and monitoring devices were installed. Additional monitors were similarly placed throughout the remainder of the French Quarter. A total of 229 in-ground monitoring stations were placed in Area 1, and 44 in-ground monitoring stations were spaced elsewhere in the French Quarter. These in-ground stations were monitored during 1999 through 2005. In late 2001, approximately 300 more stations were added, and monitoring of these stations began in January, 2002.
The annual alate counts in areas 1 and 2 were reduced two years after treatment began in each area. The trap catches in Areas 3 and 5 showed only slight decreases in the frequency, with high catches from 1998 to 2004. This reduction is most likely because of commercial termite protection contracts by individual property owners not associated with the area-wide management program.
Although the results after two years of areawide management in Areas 1 and 2 were encouraging, the absence of further decline in the alate captures in Area 1 since 2000 suggested the continuing presence of mature colonies. Unlike native subterranean termites, Formosan subterranean termites are more likely to live in above-ground carton nests without going to nests in the earth. For this reason, colonies may be established in wooden structures and woody plants and may not be susceptible to customary in-ground treatments.
An intense inspection program was begun in 2003 to discover mature colonies that possibly remained within structures and trees. Since then, 158 properties in Area 1 have been inspected at least once. Inspection results show 19 percent had live Formosan subterranean termite infestations. The trees on 93 properties in Area 1 were inspected for Formosan subterranean termite infestations. Six of these properties had a total of 16 Formosan subterranean termite-infested trees representing 2.3 percent of the trees inspected.
In July 1999, in-ground monitoring stations both in Area 1 and outside Area 1 had about the same percentage of termites. From September 1999 through 2005, however, the percentage was lower in Area 1. During this period, in-ground activity within the treated area was about 50 percent less than activity in the surrounding area. These data indicated that treatments reduced termite numbers.
The architecture of the buildings and the design of many of the properties in the French Quarter add significantly to the difficulty of managing Formosan subterranean termites. Not only are these features difficult to treat with chemicals, they also offer easy access for Formosan subterranean termites and create highly favorable, moist conditions for establishment and survival of above-ground carton nests. The difficulty of controlling Formosan subterranean termites in the French Quarter is borne out by the persistently high levels of alate activity at specific trap locations in Area 1, even though nearly all structures have been treated for termites under the auspices of the areawide program. Another factor is alate immigration into Area 1.
The research team believes many of these remaining infestations are isolated above ground without soil contact. To further reduce the termite activity in the management zones, an inspection program followed by applications of above-ground bait stations or spot treatments with a nonrepellent termiticide has been initiated. These treatments are being used to further reduce the Formosan subterranean termite densities. Expansion of the program to include additional areas is anticipated to further reduce Formosan termite densities.
Dennis R. Ring, Professor, and Alan L. Morgan, Associate Professor, Department of Entomology, LSU AgCenter, Baton Rouge, La.; Frank S. Guillot, Program Coordinator of Operation Full Stop, and Alan R. Lax, Microbiologist, USDA, Agricultural Research Service, Southern Regional Research Center, New Orleans, La.; Debbie L. Boykin, Statistician, USDA, Agricultural Research Service, Jamie Whitten Delta States Research Center, Stoneville, Miss.
(This article appeared in the winter 2006 issue of Louisiana Agriculture.)