[Annual Termite Issue] Making Their Move

A long with Mardi Gras beads and hangovers obtained in nights of
revelry in the French Quarter, Formosan subterranean termites (FSTs) have become one of the most abundant exports from the city of New Orleans. Despite state and federal efforts to control the spread of this voracious invasive species, FSTs now have been identified in 140 counties and parishes (the local governmental subdivision in Louisiana) in 10 states.

HISTORY. While the first FST infestations in the United States were identified around the Pearl Harbor naval base in Honolulu sometime after the end of WWII, the species were not widely known to have been in the continental United States until published by Dr. Bill Spink, an entomologist with Louisiana State University, in the mid 1960s; Dr. Spink’s reports followed the first identifications of FST by Francis Weesner and Thomas Snyder. It is believed that FST first landed in naval and marine installations in Lake Charles and New Orleans, La., when ships headed back to the United States after WWII from the Pacific. Termites acted as stowaways in the ballast holds or in crating materials used to ship munitions. The crating materials were used for the construction of housing for returning GIs. Apparently, the termites remained unidentified as they spread throughout the city and started consuming utility poles and live trees. The same postwar scenario also played out, on a smaller scale, in the city of Charleston, S.C.

During the next 20 years, FSTs spread throughout southern Louisiana, aided by humans transporting or disposing infested building and plant material, scrap wood and tree limbs. In areas of the city, FSTs developed large flights of alates during swarm season. Interstate traffic of FSTs consisted of infested railroad cross ties that were recycled into landscape timbers. In an example of human-assisted ecological impact, a company in inland Rutherford County, N.C., received former railroad ties from New Orleans and processed them into landscaping timbers. Unknowingly, the company distributed FSTs nationwide. The more difficult climate of North Carolina is a testimony to the tenacious nature of this insect.

CONTROL. The behavior and biology of the insect contribute to the difficulty of its control. Established colonies can contain millions of individuals, and feature up to 15 to 20 percent soldier caste, making it possible to displace smaller, less aggressive native subterranean species. In structures and trees, colonies often create "carton" nests, which are self-contained micro-environments that preserve moisture, pheromones and discourage fungal growth and predatation. Most importantly, these above-ground nests are able to survive without ground contact and contain their own reproductives, allowing them to continue autonomously if the nest evades detection and only traditional liquid/barrier treatment methods are employed.

Another aspect of behavior that adds to the difficulty in control is the apparent cooperation between what is commonly considered different colonies. According to Dr. Brian Forschler, urban entomologist with the University of Georgia, adjoining FST colonies share a "social contract," which permits sharing habitat and food sources. This cooperation has also been noted in the research of Dr. Gregg Henderson with the LSU AgCenter. Both in laboratory studies and mark and release field observations, FST colonies that are geographically or genetically different will exploit the same food source without aggressive or competitive behavior. Henderson said that this same type of behavior has not been observed between native and Formosan genera or even within the native Reticulitermes genera. Such cooperation aides in the survival of the Formosan Coptotermes species over native species, under adverse environmental conditions, Henderson added.

The pest management and research communities are not alone in their recognition of the problems caused by the spread of FST. State and federal legislatures and regulators, often lobbied by pest management professionals and affected citizens, have responded in a variety of ways:

• The Plant Industry Board of the Mississippi Department of Agriculture instituted a quarantine of certain materials from infested areas of Louisiana, including municipal trash from New Orleans that was routinely placed in a (now infested) landfill in a southeastern county of the Magnolia State.

• For the past several years, the Georgia State Legislature has appropriated funds to the University of Georgia Extension Service for identifying, monitoring and treating Formosan infestations. Dr. Dan Suitor, a University of Georgia extension entomologist, leads the field work and regularly reports to the state legislature and the Georgia Pest Control Association, which led the funding acquisition efforts.

• Research results of Dr. Ken Grace at the University of Hawaii have encouraged state building officials to adopt standards that include foundations of crushed rock, which has been demonstrated to discourage termite tunneling and the use of treated building materials in new and renovated construction.

• Florida has adopted a statewide building code that addresses construction techniques and materials designed to prevent subterranean termite infestation.

In Louisiana — the chief exporter of FSTs — the legislature established the Formosan Termite Task Force in 1998. Appointed by the governor, it is composed of representatives from the research community, the New Orleans Mosquito and Termite Control Board (the only municipal agency in the United States charged with termite treatments of city-owned structures), the housing industry (including builders, contractors, construction material suppliers and real estate agents), affected property owners, state legislators, the mayor of New Orleans, the Commissioner of Agriculture and Forestry, and pest management professionals (the author serves as the pest management professional representative on the Task Force).

ADDITIONAL PROJECTS. The legislation also empowered the Commissioner of Agriculture to establish "Formosan Termite Zones," areas of the state in which Formosans have been identified, quarantines could be enforced and building codes could mandate the use pressure-treated wood. Over the past four years, the legislature appropriated $14 million dollars, which was directed toward these projects:

• Treating 140,000 trees on public land in infested parishes, and subsidizing treatment of trees on private property for home-owners’ associations. More than 90 pest management professional teams actually performed the treatments, based on protocols developed by the Task Force’s Technical Committee.

• Printing of an educational brochure for homeowners, and the establishment of a special Web site maintained by the Louisiana Department of Agriculture.

• Working with affected cities in the proper containment and disposal of infested tree limbs and discarded building material.

Largely through the efforts of Louisiana Senators John Breaux and Mary Landrieu, the USDA Southern Research Station in New Orleans received funds to create Operation Full Stop. In addition to funding research at the University of Hawaii, the University of Florida, Mississippi State University, Texas A&M, the LSU AgCenter, the New Orleans Mosquito & Termite Control Board and other facilities, Operation Full Stop treated virtually every structure in the 100 blocks of the historic and heavily infested French Quarter. Treatments included termite baits and the use of non-repellent termiticides, with the objective of suppressing populations over a limited geographic area. Recent alate captures in light traps during swarm season (conducted by Hender-son and the LSU AgCenter) have demonstrated a reduced numbers of alates within the treatment zone, although much work still remains before conclusions can be drawn.

Recent research has also looked at genome sequencing of FSTs to determine ecological potentials and colony structure (and how this may effect baiting strategies); exotic energies (infrared, ultrasound, thermal) and gaseous emissions and their use in detection technologies; foraging behavior and how this impacts the placement of control materials and the probability of termite infestation in a particular site.

Like the hangovers taken home by many New Orleans tourists, Formosan termites have created headaches for homeowners, researchers and regulators in places far removed from the Big Easy. With proper education, funding, attention and action, pest management professionals will help to end the unwelcome and unwanted "party" that Formosans have been enjoying.

The author is vice president of marketing for LIPCA Insurance Group, an insurance provider for the pest management industry. He can be reached at afugler@giemedia.com.