A FIRST FOR FLORIDA

C.havilandi has made an appearance in Florida and is challenging pest management professionals as it moves throughout the state.

More non-native termites have become established in Florida than in any other state. The first exotic termite to call Florida home was the West Indian drywood termite, Cryptotermes brevis, which was collected from a hotel in Key West in 1918 and now accounts for most of the drywood infestations in the state. The second and most infamous, the Formosan subterranean termite, Coptotermes formosanus, probably arrived in Hallandale, Fla., during the 1970s and has surfaced in new locations ever since.

For decades now, the western drywood termite, Incisitermes minor, has been collected many times from structures throughout the state. In late 1994, a small subterranean termite, Heterotermes sp., from the Caribbean region, was discovered in a Miami neighborhood. Only two years later, another tropical subterranean species, Coptotermes havilandi, was found infesting a Miami business less than a mile away from the Heterotermes sites. In late 1999, C.havilandi was discovered in Key West.

FINDING HAVILANDI. Coptotermes havilandi is a damaging termite and a threat to wooden structures wherever it occurs. As one might expect, C. havilandi is similar in many respects to C. formosanus. The Key West infestation of C.havilandi is especially significant for two reasons: 1) subterranean termites have never before been established in Key West; and 2) the historic district of this southernmost town is the largest in the United States, boasting a 100-block area of 3,000 wooden houses built in the 1800s. Until now, the only termite threat to these "conch houses" was from drywood species. So much so, in fact, that structural fumigation is a part of the local culture. Although still in the non-historic east side of the island, it is only a matter of time before C. havilandi will begin to impact Key West’s historical buildings.

Coptotermes havilandi is native to Southeast Asia. Its propensity for infesting boats has spread this species far beyond its native range and is no doubt responsible for its arrival to Florida. It was collected in the Marquesas Islands (Pacific Ocean) in 1932 and Mauritius and Reunion (Indian Ocean) in 1936 and 1957, receptively. In the Western Hemisphere, this species was first reported in Brazil in 1923 and in Barbados in 1937.

Recent collections from other West Indian islands include Antgiua, Barbuda, Cuba, Grand Turk, Guadeloupe, Little Cayman, Montserrat, Nevis, Providenciales, Puerto Rico (San Juan) and St. Kitts. It has also been collected in southern Mexico and possibly occurs on Jamaica and Virgin Gorda, B.V.I.

Dade County, Fla., is the only known locality where C.formosanus and C.havilandi have both become established. Elsewhere in the world, these two widely introduced species are geographically isolated. Coptotermes formosanus usually invades mildly temperate climates (to 35 degrees north latitude in the United States), while C. havilandi is limited to more tropical localities as noted previously.

On a few Caribbean islands where this species has been present for decades, C. havilandi has invaded some natural woodlands. In Florida, it has been collected only from buildings and ornamental trees near buildings or boats. Three private boats docked in Southeast Florida have been found with shipboard infestations arriving from Jamaica, Virgin Gorda and Providenciales. Shipboard infestations are the most likely means of spread of this pest and best explains how the community of Key West was infested.

HAVILANDI SPECIFICS. Superficially, soldiers of C. havilandi resemble those of C. formosanus. Both species have a large opening on the forehead called the fontanelle. When viewed from above, both also share teardrop-shaped heads. Microscopic examination of the fine hairs on the head reveals diagnostic differences. Coptotermes havilandi have one pair of hairs near the rim of the fontanelle, while in C. formosanus, tow pairs originate around the fontanelle. Additionally, the lateral profile of the top of the head just behind the fontanelle shows a weak bulge in C.havilandi that is absent in C. formosanus. As with C. formosanus, C. havilandi soldiers constitute about 10 to 15 percent of foraging groups, aggressively bite when challenged and exude a white mucous-like secretion from the fontanelle.

The alates of C.havilandi are slightly smaller than those of C. formosanus (total length with wings about 13 to 14 mm vs. 1.5 mm, respectively). The head, pronotum and dorsal abdomen of C. havilandi alates are brown, while those of C. formosanus are a lighter yellow-brown or orange-brown. The darker pigmentation of the C. havilandi head provides a contrasting background for two light patches on the face, called antennal spots. In C. formosanus the antennal spots are barely, if at all, visible. Wing hair length is shorter in C. havilandi than in C. formosanus.

Like C. formosanus, C. havilandi swarms occur at dusk or at night when large numbers of alates leave the colony. In Florida and the West Indies, C. havilandi flights have been recorded between February and April. The C. Havilandi flights end about when the C. formosanus flight season begins. Porch lights, indoor lights and video monitors often attract the altates inside, especially when doors and unscreened windows are opened.

When large numbers (hundreds to thousands) of alates are found indoors, their presence is usually indicative of a structural infestation. Alates flying indoors are unlikely to find the moist wood/soil substrate they need for successful colonization and succumb quickly to desiccation. It is likely, however, that most dispersal flights will produce a few new colonies that may become a damage threat in future years.

Like other structure-infesting species of Coptotermes, damage resulting from a C. havilandi infestation can become severe in a matter of months when a structure is invaded from the ground by a large, mature colony. Dispersal flights, foraging tubes or damage are usually the first indications of an infestation. Advanced stages of infestation are indicated by the incorporation of nest material (carton) in hollowed wood or existing voids. The same management strategies employed for C. formosanus should be considered for C.havilandi. In research conducted by Dr. Nan-Yao Su, the Sentricon® baiting system has been successful in controlling C. havilandi in Florida, Puerto Rico and Little Caymen Island.

The author is a professor of entomology at the University of Florida, Ft. Lauderdale. He can be reached at rscheffrahn@pctonline.com.