Killing Termite Colonies
Killing termites is dead easy.
They are soft and susceptible to any insecticide; just breaking apart their workings will expose them to the hostile climate and they will die.
Killing termite colonies requires some knowledge but not as much skill compared to years past. See the side box on Bill Flick’s discovery of the principle which has resulted in today’s most reliable colony killing treatment procedures.
If you know for sure exactly where the nest is, you can physically or chemically destroy it. (Details further down this chapter). However, most termites are discovered by accident or as the result of an inspection.
Instead of using Bill Flick’s arsenic or other products the pest industry restricts to their own use, do-it-yourselfers can purchase a product containing chlorfluazuron.
This is safe for homeowner use. It can be used to feed termites in monitors set in the ground or to feed termites inside timbers above ground level. This same chemical is used by the majority of the professional service industry but their labels restrict its use to approved technicians. The only registered product which doesn’t have this restriction is from Termi-Fix P/L called Colony Killer Termite Bait. , This means anyone can buy and use it. This bait is not suitable for controlling Mastotermes, the Great Northern Termite. You can easily identify them: they are 13-15mm long, (that’s more than half an inch) and their distribution is generally North of the Tropic of Capricorn. There is a special section on Mastos further on in this section.
The first termite killer
It is almost 100 years since Bill Flick, a dairy farmer near Byron Bay worked out that termites were social insects like bees which left the hive to bring back honey. He reasoned the termites must be taking food back to the nest, so, if he could puff a light dusting of arsenic into their working galleries, the workers would not die before they got all the way back because arsenic is a slow-acting poison. The termite workers would then feed the arsenic along with the chewed wood to those in the nest. It worked. At that time if termites got into a house, you repaired it and sold. Bill changed all that. The Flick family built the largest pest control business in Australia.
Bill’s principle of adding a contaminating chemical to the internal feeding areas is the basis of the modern use of insect growth regulators. The process is most effective, almost foolproof and there are no human toxicity issues at all.
Chlorfluazuron inhibits the production of chitin which is the hard outer shell of insects. It is also known as an Insect Growth Regulator (IGR). The effect is on the nymphs in the nursery area surrounding the queen in a subterranean nest. The nymphs cannot produce the new shell they need to grow to the next stage and they die… thousands of them. The decomposition gases and the resulting fungus makes the nest uninhabitable. The queen dies and the workers and soldiers out in the food areas survive for only a few more weeks.
You can be more confident of a successful kill using the baiting/feeding method than the dusting or foam introduction methods.
As one technician explained it: “If termites are harvesting the bait over a few weeks, they are definitely taking it back to their nest; if you dust or foam and there are no termites in the affected area after a couple of days, it could be they have abandoned the workings because you made it too dusty or too wet or the chemical was too strong.” There can be another reason (which also applies for the feeding procedure): if anyone digs outside or in some other way accidentally severs the underground connection tunnel back to the nest— there won’t be any termites visible in the galleries, but it’s not because the nest is dead.
Feeding termites in in-ground monitors is a mainstream approach used by the industry for more than a decade since the IGRs were approved for termite control. Professionals use monitors and baiting because it works.
The three main subterranean termites live and forage for food through soil. If monitors are placed in soil around buildings, the chances are in the high probability range that they will find one. The more monitors you put around, the more likely and the sooner you could expect to intercept a termite colony. These foraging scouts may be from a new colony in its first or second year, but it might also be a decade old colony that is still trying to find a way into your house over or through a degrading chemical barrier.
You can’t make the termites find your monitors. But once they do find them and you know they are there, feeding them is easy… and hard to get wrong.
Making your own monitors can be as simple as burying a container full of wood blocks, cardboard or a combination of both. Entrance holes or slots at least 5mm wide will allow easy termite entry into the container. A removable lid makes it easy to check for live termites and to add the chlorfluazuron bait. You also need to consider making your monitors big enough to hold a significant number of termites because the more termites feeding, the faster a significant quantity of bait is transferred to the nest — wherever it is. You will need to be able to open the monitor and add the bait while hardly disturbing them. The Shedos are easily scared off; they may leave a disturbed area for 3 hours, three weeks or three months — you get the idea. (They also need at least twice as much bait to kill a colony as the Coptos, so you will risk disturbing them more often during the process). Lastly, you need to be able to find your monitors easily and regularly; it is very easy to lose track of where you put them if they are covered with leaf litter, mulch or ground cover plants.
You should have at least 4-6 of them around a house on a small (500-600sq m) block, more on a bigger block and more again if you have sheds, ramps, livestock pens/stables etc.
You can’t tell how big a nest is by looking at the termites. Termites of a species are the same size whether the colony is big or small. Multiple feeds are normal. Small colonies will require a couple/three doses; really large colonies may need ten or more doses. If you are feeding the same colony from 2, 3 or 4 monitors, the nest will probably die off quicker because they are getting bait to the nest from more sources. The amount of bait used will be about the same. Towards the end, the number of termites visible at bait replenishment time will be fewer and fewer. You may not need to add more bait. Keep inspecting every couple of weeks, then one time there will be no termites. Wait another week just to be sure.
Termites and temperature
If you check your monitors when they are hot from direct sunlight, you may not see live insects. This is probably because they couldn’t cope with the heat. Checking again when the monitors are shaded may reveal termites working merrily away once more. In-ground monitors that are set right into the ground may fill up with water after rain and it may be several days before termites return. Always confirm live termites before adding the bait.
Chlorfluazuron may take longer to kill than the dusts and foams but the nest is just as dead and there is no hazard to people or pets (because we don’t have an outer shell). As reassurance, once termites begin eating the treatment they don’t usually stop until the colony is dead (or you let them run out of the treatment). What you don’t use will keep for years.
A monitor that can be bought on-line can hold 6 litres of termites as they are mostly above ground. You can see through a clear cap at the top to note if a purpose-left hole in the cardboard cartridge has been covered in with the ‘mud’ mixture which is their signal to you they have arrived. The bait can be added at the top in less than half a minute to minimise disturbance.
They are UV protected polypropylene and expected to last more than 10 years. The same company has designed dose-sized light proof feeders with a disc that can be prised out of the base so termites can access. These bait feeders can be used either in the tops of their monitor (or any monitor) or they can be attached to the outside of infested timbers so termites can enter and harvest the bait.
See the commercial details for the monitors and the chlorfluazuron bait on www.termitetrap.com.au
Feeding termites in above ground monitors is sometimes necessary to try and intercept termites that have been badly disturbed and left the damaged area. For example, if termites were discovered in a crate, carton, toolbox, etc which was removed before you noticed their presence, it is almost impossible to put things back as they were and expect the termites to continue eating so you could introduce a bait. They will normally block off their access tunnel at say, the expansion joint in the concrete floor or where they entered the area through a small gap in a corner. (See photos).
If damaged timber has been stripped out, you have to expect termites will eventually return because the colony hasn’t been killed and there is no absolute 100% way to prevent them coming back. To retrieve the initiative, one approach is to place some enticement near where you think they are likely to find it. You can make your own above ground (or within the building) monitor and it doesn’t have to be that flash.
The monitor you make must:
- Contain cellulose material (wood or cardboard) without preservatives.
- Be accessible to termites (and not inconvenient to your day to day life).
- Be placed in a likely spot such as over the expansion joint or in a corner where they were.
- Be light-proof so termites will be happy to enter and begin their harvesting.
- Be able to be inspected by you without scaring them off
- Have an opening or a place where you can insert or attach bait. (There is no limit to size other than it shouldn’t clutter up your living/working space).
Your monitor can be as simple and easy to make as filling up a cardboard carton with a few wood blocks and some damp cardboard (reasonably but not too tightly packed). You can make a simple opening for inspection and baiting by cutting out say, a 100x200mm area in the top flaps and then laying a piece of laminate, metal sheeting, whatever… over the opening. To inspect? Just lift the sheeting. To feed them just place in the wet bait and replace the lid. If your monitor is to go over an expansion joint or against the spot you know termites have come from, look carefully and you may see their ‘mud’ mixture in the joint where they have resealed. If you can’t find such a spot, termites are likely come looking again if you give them a little more enticement. Wet the area lightly (and regularly) so the water soaks into the expansion joint.
Feeding termites in other situations is still a matter of following the same principles.
DO NOT waste bait by adding it to timbers that do not contain live termites. The colony is killed only if workers take enough of the bait back to the nest. And they will only take it if they can harvest it, undisturbed, from inside the damaged timber you have found.
Should you find termites in timbers such as the window/door frames, skirting boards inside, or in studs, posts, roof and foundation timbers of any structure, you need to make a small hole into the timber, actually see live termites then add a light-proof cache of the bait covering the hole in the timber. Here’s how:
Make an opening into the termites using a pointed knife or fine screwdriver. The hole should be no bigger than about 5mm diameter tobegin with. (It should be enlarged only when it is time to add the cache of bait). You can pry into the surface of the timber where it feels spongy, thin or hollow. You can also pick away at any of their ‘mud’ used to fill up joints cracks or splits in the timber. It is only as a last resort you should attempt to open a tunnel on a timber or foundation surface.
Phone for advice before you try this… 1800 12345 7.
Once you have broken through into where it is hollow, wait for a minute or so. If termites are there, the soldiers usually come to guard the opening while workers repair it. You will see their antennae and their heads blocking the hole. If no live termites appear, leave the hole open and come back later or check next day. If they are still using the timber, the hole will be repaired and this confirms they are ready to be fed.
If the timber has a flat surface, make the hole away from corners so you can line it up with the hole in the bottom of the feeder. If the access hole to the termites is on a round post or another situation where you cannot fix the feeder to it, you can make a pouch of aluminium foil and duct tape to hold the bait in place. The foil provides protection from light and ants.
If you are using the foil method, carefully pull back the edge of the sticky tape to inspect and to replenish the bait. If you are using the feeder method, it is less disturbing if you can add more bait to the original feeder.
Killing termites in trees
The termites you may see as dark brown nests high up in a tree are seldom pests of significance. But the main subterranean termites that do that 99% of the $damage we mentioned earlier, will often nest inside the central ‘pipe’ or hollowed out heart of a mature tree. Mastos, the giant northern termite, don’t always wait for the decay of the pipe. They kill palms and healthy mango trees. (See the special box on Mastos)
If at colonising flight time a termite couple find their way into a hollow tree through maybe a dead/broken-off branch or in through a scar from fire at the base, they could not possibly have better conditions. There’s plenty to eat, moisture and protection. A 50 metre travel to your home would not be out of the question.
If you have a large eucalypt, peppercorn or a mature fruit tree nearby, you should check it. Use an 15-20mm auger bit long enough to drill into the centre of the trunk at about shoulder height. Drill at a slight downward angle and when you feel less resistance it will be because you have reached the pipe. As you pull the bit out, look to see if any termites are in the fluting. If not, you could slip in a long thin grass leaf into the drill hole, leave it there for a minute and withdraw it slowly. Termites may be found holding on, ‘attacking’ it. If still no live termites are found, come back in half an hour or next morning; if there is termite life inside, they will be repairing or have repaired the opening using their ‘mud’ mixture.
In this situation you don’t need to see live termites; it’s just more satisfying to know you have actually killed a colony when you take the next steps…
- Re-open the drill hole if it has been repaired
- Using a funnel, plastic tube and watering can/bucket, pour at least 20-30 litres of a chlorpyrifos or a bifenthrin solution down into the tree. These insecticidal concentrations can be purchased from a local hardware store. They may be known by various brand names but the active ingredients are on the front panel of the label. They are poisons and you should read the label for dilution and safety directions.
Killing termites in mounds
Termites that build mounds are subterranean but not included in the termites that do 99% of the $damage to homes. This is because mounds are very visible, not tolerated in home circles and it is very easy to kill these colonies by physically destroying the mound. If you are on an acreage property, make it your rule not to allow any mounds to develop within 200 metres of a building or other structure. Use a crowbar, a pick/mattock to break open the top/sides.
The outer is often very hard. (Years ago, mounds were used for building homestead tennis courts). The less dense and crumbly interior is easier to break. The queen and the nursery are at the base of the mound and if you can’t physically get down there, use 20-30 litres of the dilute insecticidal mixture as above. If you don’t finish off the queen, the colony will be re-built in weeks and you’ll have to try again.
The Giant Northern Termite Mastotermes darwiniensis destroys houses, trees, vehicle tyres (yes, rubber tyres!) and many other materials, faster than any other termite. They don’t cause the most dollars worth of damage in Australia; that title goes to the Coptos, simply because Coptos distribution covers all the mainland (including where Mastos thrive) and consequently they run up their dollars in the high population cities/suburbs.
Identification is pretty easy: they are 13-15mm long (that’s more than half an inch). Most other termites are less than 10mm. They don’t build big mounds; those magnetic (north-south) mounds up that way are grass eaters.
Mastos are easy to entice into monitors. It is a good plan to use timber in the monitor as well as cardboard otherwise they may eat everything and have moved on within a month or less of finding it. Inspect monitors every week or two. If you find live Mastos, the IGR (chlorfluazuron) baits are ineffective, you will need to call in a professional who will probably use a fipronil product. If you are apprehensive of chemicals, do not worry unduly. Fipronil is the chemical in Frontline which is put directly onto the skin of dogs to kill and prevent fleas. A dilute 3 ml/litre solution of fipronil is even less toxic.