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PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND

Australian subterranean termites in New Zealand

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Formerly known as the Forest Research Institute, Scion has been a leader in research relating to forest health for over 50 years. The Rotorua-based Crown Research Institute continues to provide science that will protect all forests from damage caused by insect pests, pathogens and weeds. The information presented below arises from these research activities.

Forest and Timber Insects in New Zealand No. 62,
Australian Subterranean Termites.

Revised 2009
Based on G.R. Sandlant (1985)

Insect:  Coptotermes acinaciformis (Froggatt), Coptotermes frenchi Hill (Isoptera: Rhinotermitidae)
 

Fig. 1 - Subterranean termite nest in below ground portion of hardwood power pole.
This pole originally imported from Australia, was in use for about 30 years before the nest was discovered.
Diameter of pole 230 mm

Type of injury
In New Zealand, nests of Coptotermes acinaciformis and C. frenchi have been found only underground and have always been directly associated with timber imported from Australia (Fig. 1). Logs in contact with the ground, stumps, dead standing or fallen trees, and untreated poles, posts, and construction timbers that are near to nests may all be attacked and destroyed by foraging workers tunnelling underground. Workers may also form earthen runways across concrete foundations to provide access to the timber in buildings (Fig. 2). Living trees may be
invaded via the roots.

The interior of timber attacked by subterranean termites is reduced to a series of galleries, with paper thin, longitudinal partitions of wood (usually the latewood bands) between them (Fig. 3). Sometimes this partitioning is entirely consumed and the large gallery so formed contains a framework of regurgitated material called honeycomb. Damage can be very extensive and remain undetected for many years. The presence of mud which subterranean termites carry to their galleries and the absence of faecal pellets distinguish the workings of these termites from
those of drywood termites (Leaflet No. 59).

Hosts
Australian subterranean termites will destroy dead wood of a wide range of hardwoods and softwoods. No building timber in New Zealand is known to be resistant to damage.

Attack on living trees in New Zealand has occurred in Leptospermum and Kunzea (manuka and kanuka), Chamaecyparis lawsoniana (Lawson cypress), Cupressus macrocarpa (macrocarpa), Juglans (walnut), Populus (poplar), Salix (willow) and Prunus, but all of these were invaded by workers from a colony which had its nest in nearby Australian hardwood timber. No nests have been found in New Zealand-grown trees.
 


Fig. 2 - Runways made by subterranean termite workers over the concrete foundations and floor joists of a building.


Fig. 3 - Australian hardwood timber (100 x 75 mm) eaten by subterranean termites, and showing remaining wood partitions.
 
In Australia many species of living trees and shrubs are attacked by these termites. The nests themselves can even be present in living trees. Those of
C acinaciformis are known to occur in 25 species of Eucalyptus (eucalypts) as well as in Agathis robusta (northern kauri pine), Araucaria cunninghamii (hoop pine), Callitris (cypress pine), Casuarina (sheoke), and Grevillea robusta (silky oak). Nests of C. frenchi have been found in Eucalyptus and Araucaria cunninghamii .

Distribution
Both subterranean termites are native to Australia. Coptotermes acinaciformis has been collected in all states except Tasmania, and C. frenchi is known from South Australia, Victoria, New South Wales, southern Queensland, and the Australian Capital Territory. The first discovery of these termites in New Zealand was in Auckland during the 1930s.

In New Zealand, subterranean termites have always been found associated with Australian hardwoods imported mostly before adequate timber inspection services existed. Most discoveries have been made in Auckland City and adjacent districts, and in the Bay of Plenty. Other occurrences have been at Rawhiti in the Bay of Islands, Whangarei, Whangamata in the Coromandel Peninsula, at Waipoua in Poverty Bay, near Ruatoria, and in Hamilton, New Plymouth, Wellington, Otorohanga Nelson and South Rodney. As almost all sites are at low altitude near the coast, mildness of climate seems to determine where imported colonies can survive. When a colony is discovered MAF Biosecurity New Zealand arranges its destruction. Two sites are currently being monitored for termite activity after treatment with hexaflumuron baits – one in Nelson, and one in South Rodney. Eradication will be officially declared following five years without termite activity (Philip et al. 2008).

Economic importance
In Australia subterranean termites cause widespread damage to living hardwood trees, principally eucalypts, which become unsuitable for milling because of the galleries excavated in them. Undetected colonies which survive tree felling and milling often remain active in timber used for poles and sleepers. Up to now, plantations of exotic conifers in Australia have escaped attack, although C. acinaciformis has been found in dead trees and stumps of Pinus radiata (radiata pine). Both termite species have become well-adapted to urban and industrial situations where they eat hardwood and softwood framing and sheathing timbers, poles, posts, and bridge and wharf timbers. Coptotermes acinaciformis also attacks horticultural and ornamental trees, vines, and shrubs, and has damaged such inedible items as plastic- and lead-sheathed electricity cables, and agricultural piping. Annual financial losses caused by C. acinaciformis in Australia have been estimated at many millions of dollars.
 
 

Fig. 4 - Diagram of Subterranean termite colony showing under-ground tunnels and earthen-covered runways leading to additional food sources.

In New Zealand subterranean termites have caused considerable damage to buildings which they have invaded via tunnels from nests in nearby hardwood poles. They have not yet been found in pine or eucalypt forests but they could be as important a pest here as they are amongst eucalypts in Australia.

Description
The social organisation and cases in a colony of Coptotermes are similar to those of the New Zealand drywood termite Kalotermes brouni (Leaflet No.59). However, whereas all drywood termite young (or "nymphs") eventually become winged reproductives, a great proportion of nymphs in a Coptotermes colony remain perpetually immature. These are the workers which excavate wood and soil, tend eggs and young, and feed the king and queen, the developing reproductives, and the soldiers. The workers are the most numerous caste in a colony. The relative numbers in each caste is controlled by hormones present in droplet exudations produced by the queen and passed around by the workers which groom her.

The workers (Fig. 5) are pale yellow, reach a length of 5 mm, and are blind. The head is round when seen from above and somewhat flattened. The black jaws protrude slightly, and the antennae have 15 or 16 segments.
 


Fig. 5 - Subterranean termite workers.
The line shows natural length.



Fig. 6 - Subterranean termite winged reproductives.
The line shows natural length including wings.

Some nymphs grow wing buds which become larger each time the skin is shed. These nymphs are larger overall (6.5 mm) than nymphs without developing wings, but are otherwise similar in shape. During wing development the head and upperside of the body become darker and eyes appear. When fully grown these individuals are the winged male and female reproductives (Fig. 6) which emerge, disperse in mass flights, pair off, and attempt to found new colonies. The heads and bodies of these reproductives are brown, and the antennae are yellow. Body length is about 7.5 mm. There are two sets of slightly brownish wings which at rest lie flat over the abdomen and project about 4 mm beyond its apex. The leading edges of the wings are thick and cream coloured. After the nuptial flight the wings break off along the lines of weakness at their base. Young nymphs of either sex, and even nymphs with partly-formed wing buds, can develop into blind soldiers (Fig. 7). These are up to 6 mm long, with a yellow to pale brown, slightly pear-shaped head, and black, curved jaws. There is a circular opening or "fontanelle" on the forehead (Fig. 8), and from this a sticky, white, acidic fluid is exuded and used in colony defence. The fontanelle and its secretion occur only in subterranean termites and distinguish Coptotermes soldiers from those of other termites in New Zealand.
 


Fig. 7 - Subterranean termite soldiers.
The line shows natural length.

Life history and habits
Little is known about the life history of Coptotermes in New Zealand. All colonies found here have been directly associated with imported Australian hardwoods and may survive for 20-30 years in this material before more food supplies are required. At this stage underground foraging tunnels and, if necessary, mud-covered runways are constructed. Colonies in New Zealand have often been large enough to produce winged reproductives, with flights taking place between early September and late December. However, there is no evidence that colonies have ever become established here from such flights.

In Australia colonies can contain over 1 million individuals and produce 60 000 winged reproductives in a year. Flights often take place at dusk in association with rainy or stormy weather, and winged reproductives from different colonies over large areas of country may emerge at the same time. When new host material is found a male and female pair start to tunnel in before they mate. The female is the queen of the new colony and her abdomen becomes enormously enlarged as egg production increases. At first all young are workers; up to two years may pass before winged reproductives are produced and three years before there are any soldiers. Nymphs originally destined to remain immature workers can become winged reproductives or soldiers at a later stage should the colony be disturbed or partially destroyed. If the queen should perish certain of the immature nymphs may develop into wingless reproductives and produce eggs for the maintenance of the colony.

In the warmer parts of Australia Coptotermes may construct nest mounds which can be up to 3 m tall. Nests may also be present in stumps or living trees. In trees nests have been found up to 9 m above the ground, but contact with the soil by galleries or covered runways is always maintained. Soil moisture is essential for these thin-skinned termites since they become desiccated if the humidity in the nest falls below 90%.

Control
All discoveries of suspected subterranean termites should be reported to the MAFBNZ disease and pest hotline on 0800 80 99 66. Home treatment should NOT be attempted. Evidence should be disturbed as little as possible because if runways and galleries are broken the subsequent chemical treatment is made more difficult and lengthy.

Bibliography
Ahmed (Shiday), B.M. and French, J.R.J. 2008: An overview of termite control methods in Australia and their link to aspects of termite biology and ecology. Pak. Entomol. 30 (2): 101-118.
Bain, J. and Jenkin, M.J. 1983:.
Kalotermes banksiae, Glyptotermes brevicornis and other termites (Isoptera) in New Zealand. New Zealand Entomologist 7 : 365-371.
Gay, F.J. and Calaby, J. H. 1970: Termites of the Australian region. Pp. 393-448 in Krishna, K. and Weesner, F.M. (ed). Biology of termites vol. 11. Academic Press, New York.
Kelsey, J.M. 1944: The identification of termites in New Zealand.
New Zealand Journal of Science and Technology 258 : 231-260.
Kelsey, J.M. 1946: Insects attacking milled timber, poles and posts in New Zealand.
New Zealand Journal of Science and Technology 288 : 65-100.
Miller, E.M. 1969: Caste differentiation in the lower termites. Pp. 283-310 in Krishna, K. and Wegsner, F.M. (ed). Biology of termites vol. 1. Academic Press, New York.
Milligan, R.H. 1984:
Kalotermes brouni Froggatt (Isoptera: Kalotermitidae). New Zealand drywood termite. New Zealand Forest Service, Forest and Timber Insects in New Zealand Leaflet No. 59.
Philip, B.; Pearson, H. and Bennett, S. 2008: Australian termites in New Zealand. Biosecurity 82: 12-13.
Ross, M.G. 2005: Responding to incursions of Australian subterranean termites in New Zealand. Surveillance and Incursion Response Division, Ministry of Agriculture and Forestry, Wellington. 21 p.
Sandlant, G.R. 1985: Coptotermes acinaciformis (Froggatt), Coptotermes frenchi Hill, (Isoptera: Rhinotermitidae). Australian subterranean termites in New Zealand. New Zealand Forest Service, Forest and Timber Insects in New Zealand No. 62.
Waller, J.B. 1984: Household pests in: Scott, R.R. (ed) New Zealand pest and beneficial insects. Lincoln University College of Agriculture, Canterbury, pp 205-220.
Yule, R.A. and Wylie, F.R. 1983: Subterranean termites in Queensland. Queensland Department of Forestry, Timber Note No. 9

Identification Guide

  Subterranean termites Drywood termites
Workings No faecal pellets Solid faecal pellets with rounded ends and six flat sides
Mud present Mud absent
Covered runways or tubes as thick as a
pencil or larger
No runways
Soldiers Head yellowish with  curved  sides, and curved upper and lower surfaces Head dark brown with sides, and upper and lower surfaces almost parallel and straight
Jaws slender and sickle-shaped with no visible teeth on inner border Jaws strong, broad, and with fine teeth along inner border Jaws strong, broad, and with fine teeth along inner border
No eyes Black or white eyes present
Opening, "fontanelle", on top of head from which white sticky fluid is exuded when termite is alive No "fontanelle" or sticky exudation
Total body length not more than 6 mm Total length greater than 6mm


                                 
 
 

 

 

This information is intended for general interest only. It is not intended to be a substitute for specific specialist advice on any matter and should not be relied on for that purpose. Scion will not be liable for any direct, indirect, incidental, special, consequential or exemplary damages, loss of profits, or any other intangible losses that result from using the information provided on this site.
(Scion is the trading name of the New Zealand Forest Research Institute Limited.)

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