Introduction
The Formosan termite was described from Taiwan (Formosa) in the early 1900s, but is native to southern China. Formosan termites have long been a pest in Hawaii, first collected in 1896 but not correctly identified until 1905. They were first discovered in the continental states in 1956 in Charleston, S.C., then in Houston, Texas, in 1965, and the next year in Galveston. They are known from several areas in southern Louisiana: Lake Charles and New Orleans (1966), Meridian (1984) and Biloxi-Gulfport (1985), Mississippi; Mobile, Alabama (1985); south Florida and into North Miami Beach, then found in Orlando (1983), Ft. Walton Beach (1984), and in Pensacola (1985); and were discovered in Memphis, Tennessee, in 1984. In 1992, infestations were verified in Holden Beach, NC, Florence, SC, Tampa, GA, and San Diego County, CA. In 1996, infestations were verified in Spindale, NC, which is in western North Carolina. Most of the inland infestations are the result of the termites being moved in shipments of used railroad timbers recycled for landscaping purposes. On its own, it usually invades mildly temperate climates (to 35 degrees north latitude in the United States).
The formosan termite is the so-called “Super” termite of the popular press. This is primarily because of the large size of the colony and, hence, the termites’ ability to consume a large amount of wood in a relatively short period of time and to produce large evening flights of swarmers.
Recognition
About 5/16″ (14-15 mm) long including wings. Body pale yellow to brownish yellow. Fontanelle (frontal gland pore) present, distinct, opening towards front of head. Front wing with 2 dark, heavily sclerotized (hardened) veins in front portion, other veins unpigmented except for basal third. Wing translucent (slightly milky), densely covered with hairs (setae). Front wing scale distinctly larger than hind wing scale, may overlap basal portion of hind wing scale.
Soldier
Head rounded on sides, tapered or narrowed toward front, with fontanelle (frontal gland pore) on slight tubercle (very short tube) toward front of head. Mandibles lack teeth. Pronotum flat, narrower than head.
Similar Groups
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- Asian subterranean termite (Coptotermes gestroi(Wasmann); formerly C. havilandi Holmgren) swarmers smaller (about 13-14 vs 14-15 mm long including wings), head maximum width less (1.4 vs 1.5 mm), with head, thorax, and top of abdomen dark brown, and head with paler antennal spots distinct; soldier with 1 pair of hairs (setae) originating near rim of fontanelle (vs 2 pairs originating around fontanelle), and head in lateral view with slight buldge just behind fontanelle (vs no buldge); presently only in south Florida in the United States, but also in West Indian Islands including Puerto Rico.
- Eastern (Reticulitermes flavipes), dark southeastern (R. virginicus), and western (R. hesperus) subterranean termites and R. tibialis swarmers with wings lacking dense hairs and body dark brown to black; soldiers with elongate, parallel-sided head.
- Light southeastern subterranean termite (R. hageni) swarmer with wings lacking dense hairs; soldiers with elongate, parallel-sided head.
- Drywood termite (Kalotermitidae) swarmers with wings lacking dense hairs and front wing with 3 or more pigmented veins.
- Other similar termite swarmers lack wings with dense hairs, and in addition have 3 or more pigmented veins in front wings.
Damage & Signs of Infestation
This is essentially the same as that caused by the eastern subterranean termite, wood appearing layered and soil present, except that it happens at a more rapid rate and the large carton constructions cause walls to bulge.
Although colonies of several million termites are known, a mature colony consisting of about 350,000 workers may/can eat about 31 grams or 1+ ounces per day. At this rate, such a colony could completely consume 14 linear feet (4.3 m) of a pine 2″x4″ board in 1 year; or it would take them 25 days to completely consume 1 foot (0.3 m). However, some mature colonies may be as much as 2-28 times this large and/or there may be more than 1 colony associated with the structure.
Calculations from the latest feeding studies indicate that a colony of 3 million termites can consume about 13 oz (360 gm)/day or 167 linear feet (5.9 m) of a pine 2″x4″ in 1 year (=about 2 days to eat 1 ft/0.3 m); hence, the above 350,000 member colony would thus consume about 19.5 linear feet (5.9 m) instead of 14 (4.3 m).
It must be realized that an established, mature colony of Formosan termites may cause severe structural damage to a home in as short a time as 6 months. For this reason, it is extremely important that prospective customers be warned concerning the need for immediate control. Be sure of the identification first!
Biology
Formosan termites are subterranean termites, they typically live in the ground, build mud tubes, have a 3-caste system, etc. However, they are described as being a more vigorous and aggressive species than our native subterranean species. A mature queen can lay as many as 1,000 eggs per day.
Swarming usually follows a warm rainy day in late spring/summer and typically occurs in the evening hours, starting at sundown and ending before midnight. The swarmers are attracted to lights. A single colony of Formosan termites may release over 70,000 swarmers.
Typical colony size and foraging habits have been investigated using the dye-and-trap method. Of 8 colonies in Florida, the number of termites per colony ranged from 1.4-6.86 million, with foraging areas of about 1,743 sq ft (162 sq m) to 38,424 sq ft/0.9 acre (3,571 sq m/0.4 hectare) respectively. Foragers from the smaller colony traveled 43 m (141 ft) and those of the largest colony traveled 115m (377 ft) maximally for food. Colonies have a higher proportioin of soldiers (10-15%) as compared to most other Reticulitermes termite species (1-2%), and the soldiers tend to be more aggressive when the colony is disturbed.
Habits
These are essentially the same as for the eastern subterranean termite.
Formosans do have the habit of establishing secondary nests above ground if a constant moisture supply is available. Such a nest is made of a material called carton. It consists of soil and wood cemented together with saliva and feces. Such large nests typically cause walls to bulge.
True aerial nests (never ground contact) are much more often encountered than for the eastern subterranean termites. They account for about 25% of the structural infestations in Florida and for about 50% of those in high-rise structures in Honolulu, Hawaii. Swarmers are capable of being carried up to flat roofs by the natural updraft associated with such structures. Defects in flat roofs provide both a way for moisture and swarmers to gain entry.
In addition to structures, Formosans cause serious damage to living trees and shrubs, utility poles, landscape timbers, railroad ties, and wooden railroad trusses, often mandating replacement. They have also caused costly damage to underground telephone and electrical cables, the latter resulting in power outages in cities, by chewing through the cable’s insulation covering. Also, they are more likely to infest boats/ships.
Termite Control Naples
Control consists of placing a chemical treatment zone (second-generation nonrepellent pesticides work best) and/or an in-ground monitoring-baiting system between the termite colony and the wood of the structure. In addition, all wood-to-soil and rigid foam board/foam-to-ground contact should be eliminated (the building owner’s responsibility), any wood debris must be removed, and the wood moisture content should be reduced to below 20%. Secondary and aerial colonies are controlled by correcting the moisture problem to dry out the moisture-source area, but fumigation is sometimes necessary. Also available are above-ground termite baiting systems that are placed directly on the termite-infested wood.
If possible, cartons should be removed. They may be locally treated with appropriate products. However, since there is no reliable practical way to detect small cartons, fumigation may be advisable or necessary.