Termites

(Photo credit to termiteweb.com)

Formosan subterranean termite (Coptotermes formosanus)

Coptotermes formosanus is the most damaging termite found in Hawaii. It was first discovered in Oahu and subsequently spread to other neighbouring islands in Hawaii. The peak period for swarming is in May and June. The body of Coptotermes formosanus alates are 6 to 7 mm long and brown in color. It will be up to 12 to 15 mm long with the wings on it. The workers are about 5 mm long and pale yellow with the mandibles lack teeth. For the soldier, the size is about 6 mm long and have an oval-shaped, light brown head and dark brown mandibles. The colony of this species is always underground or under the soil, and moisture is crucial for the colony survival. Due to their underground nesting habit, the infestation is sometimes difficult to be noticed until severe damage has been done by the species.

(Photo credit to termiteweb.com)

(Photo credit to termiteweb.com)

Asian subterranean termite (Coptotermes gestroi)

Coptotermes gestroi is endemic to Southeast Asia but has been spread to other parts of the world over the last century. This species has caused tremendous damage and threat to wood structures. In Hawaii, the presence of Coptotermes gestroi was first discovered in 1963 in Oahu and there was no second infestation until the late 1990s. The second infestation was found in the building located on West side of Pearl Harbour. Currently, there are no Coptotermes gestroi recorded in other islands other than Oahu. The physical appearance of Coptotermes gestroi is similar to Coptotermes formosanus. The identification of both species required technical expertise and sometimes needs microscopic examination.

(Photo credit to padil.gov.au)

West Indian drywood termite (Cryptotermes brevis)

Cryptotermes brevis is grouped under Family Kalotermitidae, or generally known as drywood termite. This species is well known as one of the worst drywood termites in Hawaii. Alates are about 10 to 11 mm long with the wings. Soldiers are about 5 mm long and the head is brown to reddish-brown in color. The head of the soldiers are constricted and highly wrinkled. This species normally infests dry wood and does not have a connection with soil. Furniture, woodwork, and seasoned wood could be the target infestation for this species. Drywood termites will remove fecal pellets (or known as frass) from their feeding galleries.

(Photo credit to padil.gov.au)

Indo-Malaysian drywood termite (Cryptotermes cynocephalus)

Cryptotermes cynocephalus is another species of drywood termite found in Hawaii. However, its distribution is more restricted compared to Cryptotermes brevis which has a wider distribution in Hawaii. Similar to Cryptotermes brevis, this species also infest dry wood products.

Lowland tree termite (Incisitermes immigrans)

Incisitermes immigrans is grouped under drywood termite. This species rarely infest buildings. They normally live in living or dead dry wood and found predominantly along coast.

Forest tree termite (Neotermes connexus)

The body length of Neotermes connexus alates are 17 to 18 mm long with the wings and is pale brown. This species normally found in forest areas while living in the dead wood, wet wood, or living trees. In Hawaii, this species generally found above 500 ft elevation and seldom infest buildings.

How to differentiate winged form of ant and termite?

(Photo credit to termitemd.com)

Cryptotermes brevis is grouped under Family Kalotermitidae, or generally known as drywood termite. This species is well known as one of the worst drywood termites in Hawaii. Alates are about 10 to 11 mm long with the wings. Soldiers are about 5 mm long and the head is brown to reddish-brown in color. The head of the soldiers are constricted and highly wrinkled. This species normally infests dry wood and does not have a connection with soil. Furniture, woodwork, and seasoned wood could be the target infestation for this species. Drywood termites will remove fecal pellets (or known as frass) from their feeding galleries.

Prevention and Control of Termites

  • Wood treated with preservatives should be used in building construction to prevent termite attack especially in the area with high termite infestations.
  • Physical barrier could be another prevention option. Due to the subterranean termite living nature, which is primarily underground, there is a potential that we can prevent the termite infestation during pre-construction. This could be the first defense to prevent termite infestation.
  • Soil treatment is a method to place a chemical barrier between termites and building structures. It can be done at pre-construction or post-construction. There are several termiticides used in the market, some of them have repellent effects to termites while some are not repellent to termites. Repellent termiticides are usually used in pre-construction to prevent termites. Non-repellent termiticides are found to work best for subterranean termite colony elimination.
  • Bait consisted of cellulose-based food combined with a slow-acting substance (insect growth regulator) that is lethal to termites. Termite workers will consume the bait and bring back the toxic substances to share among their nestmates. This can eventually eradicate the termite colonies. The bait stations could be installed underground outside of the house, around the perimeter of the house, or indoor close to the active mud tubes.
  • Fumigation or tenting is recommended for severe or widespread infestations. Fumigant gas will be released and circulated throughout the tented home so that the fumigant gas will reach the termite and kill them. Fumigation is a process involves restricted used pesticides and must be performed by certified professionals. Home owners and pets need to leave the home during the fumigation process which normally takes about 1 to 3 days.
  • Heat treatment is another way to control termite infestation. Compared to fumigation, heat treatment is non-chemical and non-toxic. Heat will be introduced into the infested home to raise the air temperature to between 120 F and 140 F. However, both fumigation and heat treatment are more reliable and effective in eradicating drywood termite infestation where they usually have relatively smaller colonies and restricted infestation area. For subterranean termite infestation, baiting or soil treatment can be performed to achieve complete colony elimination.

References

  • Urban Insects and Arachnids: A Handbook of Urban Entomology (2005). William H Robinson. Cambridge University Press.
  • Urban Pest Control in Australia (1985). P Hadlington and J Gerozisis. New South Wales University Press.
  • NPMA Field Guide to Structural Pests, Second Edition (2007). Eric H. Smith and Richard C. Whitman.

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