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July 2012. Sources of information were requested on termites (and also carpenter bees) in Samoa.
The species were requested, but unknown.
A number of suggestions were given:
1. Spinosad, a bacterial product, was said to be good against the termites, but there will probably be need to spray a second time, say, 3 days later, to kill the next generation to hatch.
2. Boric acid, mix 75 g of the chemical with molasses and some small pieces of wood, let the mixture dry out and then place near the nest. It takes a few days to have an effect.
3. Senticon, an Insect Growth Regulator (IGR) for ground placements against termites, and Recruit for subterranean termite control (in Australia.
The system is based on a programme where a wooden detector bait, inserted in a plastic holder, is inspected regularly until the termites begin to consume the bait as a source of cellulose. Once consumption is observed, it is then replaced with another bait containing the IGR (eg hexaflumuron). The bait is taken back to the nest and exterminates the juvenile termites, eventually destroying the nest. It is a relatively slow but very effective treatment.
Carpenter bees can be controlled by using a spray into and around the tunnel. Bifenthrin or permethrin are useful as these are the least repellant of all the synthetic pyrethroids (SPs). Bees that are not present in the nest at the time of treatment should return and crawl over the treated area and die. Repellant SPs may deter adult bees from contacting the treated surfaces.
If the adult bees are not controlled then they will quickly establish another nest on untreated timber. Treat susceptible timbers as a preventative measure. EC formulations are best as these penetrate into the wood. Using deodourised kerosene as a diluent is also a good idea as the will get the chemical deep into the timber for long term residual control.
You may also use a dust application eg permethrin dust via a puffer.
It is not recommend to treat timbers in forest or bush areas as carpenter bees provide useful pollination for flowers and also are a part of normal breakdown process of dead wood in a forest ecosystem, so we are not trying to eradicate them unless you have a particular exotic species bio-security concern.
IGRs are not species specific, not even genus specific. IGRs fall into three groups:
- Juvenile hormone mimics (eg s-methoprene and pyriproxifen);
- Ecdysone Inhibitors (azadirachtin in Neem oil) and
- Chitin synthesase inhibitors (eg hexaflumuron and diflubenzuron in many of the termite baits)
Sentricon is registered on five species of Coptotermes, as well as Schedorhinotermes spp, Nasutitermes spp, Heterotermes spp, and Mastotermes spp, and maybe more species in other parts of the world.
There was mention of a problem in using Senticon in Palau: it did not work against subterranean termites. However, the IGR bait placement applications are not effective for controlling drywood termites as they need to be treated in situ with penetrating insecticide sprays. After launching Sentricon, it was found that Australian termites had a pretty refined taste for local timbers and the initially provided USA sourced wooden baits had to be replaced with locally sourced timber.
4. Additional comments were sent from Theo Evans, Singapore, on control including baiting methods based on work at CSIRO. This is given in full:
Termites from Samoa
I do not have a full species list of termites from Samoa. The species documented as present in Samoa include the native species: the ‘drywood’ species Neotermes samoanusand Glyptotermes xantholabrum (Kalotermitidae), the (sort of) subterranean Prorhinotermes inopinatus (Rhinotermitidae), and the tree nesting Microcerotermes biroi(Termitidae); and the introduced Southeast Asian drywood species Cryptotermes domesticus. All of these species eat wood.
I have seen a few reports of termite damage from Samoa. All are decades old and none list the species. Descriptions of damage are not detailed; they mention damage to timber framing, and window and door frames. Such damage could be caused by drywood or subterranean termites. I have read one detailed description of damage to a door frame, which reported hollowed out wood but no mention of mudding. I would guess this is drywood damage; probably Cryptotermes domesticus. This species is also considered a pest in forestry (see Iosua & Peseta 2003 – but note they thought incorrectly that Cr. domesticuswas indigenous).
If Samoa would would like to send good photos (including soldiers) an attempt to identify the termites can be made.
Termites from Palau
I do not have a full species list of termites from Palau either. Species include: Neotermes kanehirae(Kalotermitidae) and the subterranean and tree nesting Nasutitermes brevirostris(Termitidae). Guam has a number of introduced species, including Cryptotermes domesticus and Cr. dudleyi, also from Southeast Asia, and the subterranean Coptotermes formosanusfrom China and Taiwan.
JAs for Samoa, if Palau would like to send good photos, an identification can be attempted.
Control methods
There are many methods of termite control; I’ll mention categories here. Some categories are used for prevention of termite access, other for remedial treatment, some for both. I’ve included some examples from a variety of companies, but I am not implying endorsement.
Insecticides in soil (prevention & remedial). These are organophosphates (OPs, e.g. Dow Dursban), synthetic pyrethroids (SPs, e.g. FMC Biflex), imidacloprid (Bayer Premise) and fipronil (BASF or Bayer Termidor). These are usually liquid formulations and can be squirted into damaged timber or other termite workings as a remedial treatment (this is often off-label). Some of these ai’s are formulated as foams specifically for remedial treatment of damaged timber, as the foam gives better penetration (including vertical travel upwards) than liquid.
There are many natural product insecticides that are usually applied as liquids to damaged timber in a remedial situation. The most discussed at the moment is orange oil for drywood termites. Data on efficacy are scant for most products; most have short half lives.
Insecticides in plastics (prevention). These are all SPs and are put in the moisture membrane that protects the concrete slab and in the penetractions (e.g. deltamethrin in Bayer Kordon and bifenthrin in FMC Homeguard). These are generally installed during house construction, but I think some retro-fitting may be possible.
Insecticides in dusts (remedial). Most older products were based on arsenic salts (commonly arsenic trioxide), which is very dangerous for humans. Now there are two dusts using much safer compounds: triflumuron (a CSI) (Bayer Intregue Dust) and fipronil (BASF Termidor Dust). I have heard of dusts containing SPs, but I do not how effective these are. Dusts are usually applied to damaged timber or to bait boxes.
Gas insecticides (remedial). There is one dominant product sulfuryl fluoride (Dow, Vikane). This is mostly used against drywood termites.
Bait & monitoring stations (‘prevention’ & remedial). n.b.:
1. ‘baits’ have a toxic food whereas ‘monitoring stations’ do not. n.b.
2. Some companies promote their baiting products as the one and only method needed, including for prevention, whereas other companies do not – thus the quotes. All but one of the commercially available bait stations use chitin synthesis inhibitors (CSIs) (e.g. either noviflumuron or hexaflumuron in Dow Sentricon, chlorfluazuron in Ensystex Exterra, bistrifluron in Sumitomo X-term). The sole exception is the mitochondrial metabolic inhibitor sulfluramid (FMC Firstline), but I think this is available only in the USA. There are commercially made DYI monitoring stations and it is possible to make a monitoring station yourself using everyday items. Either liquid, foam or dust insecticides are applied once the monitoring station has been infested with termites. More on baits below.
Physical barriers (prevention). The best known examples are made from crushed rock (Basalt Barrier from Hawaii and GraniteGard from Australia) and stainless steel mesh (Termi-mesh), but include a variety of flashing and dampcourse made from stainless steel or marine grade aluminium that act as termite barriers as well. These are generally installed during house construction, but I think some retro-fitting may be possible.
Biocontrol (?). As far as I’m aware, there are no biological control agents commercially available for termite control. Entomopathogenic fungi (Metarhizium and Beauvaria) and nematodes have been identified and tested in several places around the world, with successful laboratory trials but mostly unsuccessful field trials. Michael Lenz, now retired from CSIRO, did have successful field trials using a nematode against species of Neotermes in coconut and mahogany in the south Pacific, but I do not think this research has continued into a commercial product.
Termite baiting
First a comment on registration of baits in Australia. The Australian Pesticides and Veterinary Medicines Authority (APVMA) registers most products in Australia for “termites”. This is particularly true for older products, although newer products appear to have had greater testing requirements, and so may have categories (e.g. “drywood termites” or “subterranean termites”) or species names listed. But the latter is very rare.
(I am becoming more familiar with registration in various Southeast Asian countries; it appears that most do not list species either.)
An example. The active ingredient hexaflumuron in Sentricon is registered by the APVMA against “termites”: search http://services.apvma.gov.au/PubcrisWebClient/welcome.do. The label states “Subterranean Termites”: http://www.infopest.com.au/extra/asp/infopest/nra/labels.asp?prodcode=64761. Only the “Sentricon Technical Manual” from DowAgroscience Australia lists names of species, but only in the context of how frequently monitoring should take place; there is no mention of efficacy against any species: http://www.dowagro.com/au/prod/sentriconII.htm
The same is true for chlorfluazuron in Exterra, except the label explicitly exempts Mastotermes darwiniensis. This appears to be a consequence of timing of registration as mentioned above.
All the CSIs used in commercial termite baits were developed against a few species in Coptotermesand Reticulitermes. These two genera are both in the Family Rhinotermitidae and very closely related. Thus it is not surprising that the CSIs work well for each. However, the data for other species, particularly in other termite Families, is less encouraging. Note that there is little data in published scientific studies for other termites. What little there is consistently shows termites in other families either require more bait, over longer time periods to be effective, or that they are not effective. The latter explains the exemption for Mastotermes darwiniensison the Exterra label; in fact I do not know of one study, published or otherwise, that has demonstrated CSI efficacy against this species. Fungus growing termites in the Family Macrotermitidae appear to be particularly resistant to CSIs. This makes biological sense: CSIs block enzymes, enzymes vary phylogenetically, thus more distantly related species will have greater variation between their enzymes, which lowers efficacy.
The info about Sentricon bait stations in Australia is correct. CSIRO did the research showing that the Southern Yellow Pine, Pinus taeda, used in the USA bait stations was not palatable, and this wood was replaced by Australia Mountain Ash, Eucalyptus regnans. Incidentally, later research in the USA showed the SY-Pine was not much liked by Coptotermes formosanuseither. I don’t know whether it was replaced in US bait stations.
Reference:
Iosua F & Peseta O. 2003. Development of Forest Health Surveillance Systems for South Pacific Countries and Australia; country report – Samoa. Canberra, Australian Government, Australian Centre for International Agricultural Research
5. Last year there was a discussion on termites on Pestnet as a member reported a termite infested house in West New Britain, PNG. The disucssion was around the use of Termidor (containing fibronil) used as a dust. The discussion can be found at:
Note that fipronil is banned in some countries because of its effects on bees. There is a fact sheet here, put out by the US EPA and Oregon State University. http://npic.orst.edu/factsheets/fipronil.pdf.
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