Termite Life Cycles And Habits

termite control - construction debris

Bulldozers make plenty of fragments which lie on or just below the surface after a sub-division of once-rural land is covered in houses and landscaping

It’s a cycle, so let’s break in and start at the beginning of the colonizing flight.

New colonies begin when winged reproductive termites fly out of a mature colony in the first weeks of summer when the heat and humidity outside are a close match to conditions inside the nest. They can, but seldom fly more than 100-200 metres and of the thousands that leave ‘home’ full of hope, most fail to establish a successful colony. The first problem is boy meeting girl, the next is finding something to eat which is in contact with damp soil before they themselves are eaten by birds, ants, spiders, echidnas, lizards, etc.

In their natural bush it’s relatively easy for them to find a fallen branch, leaf or bark mulch, a stump or if they are supremely lucky, a hollow tree. Around most homes there are tree and wood fragments mixed up in the soil and which gives the ‘honeymooners’ some homemaking options. Although more than 99% of couples fail to get past the first summer, some will become established.

termite control - colony-diagram

Once a nest site is chosen, the young couple begin to excavate and secure a chamber just below ground level adjacent to the wood/food. They tend their first eggs and the hatching nymphs that grow into workers. When they have what they deem to be enough ‘subjects’ they declare themselves ‘royalty’ and spend the rest of their lives making babies they don’t have to look after.

The nymphs grow in a series of moults, each a size larger than before. Initially they are all worker caste but later some nymphs become soldiers. It is only 3-6 years later that some of the nymphs will become reproductives — but let’s not get ahead of the story. The workers not only chew off cellulose (the basic component of wood) to feed themselves, they also have to feed everyone else: nymphs, royals, soldiers. If the initially chosen wood fragment was the size of a fist or maybe a boot, it won’t take more than a few months for the food to run out.

Once a nest site is chosen, the young couple begin to excavate and secure a chamber just below ground level adjacent to the wood/food. They tend their first eggs and the hatching nymphs that grow into workers. When they have what they deem to be enough ‘subjects’ they declare themselves ‘royalty’ and spend the rest of their lives making babies they don’t have to look after.

The nymphs grow in a series of moults, each a size larger than before. Initially they are all worker caste but later some nymphs become soldiers. It is only 3-6 years later that some of the nymphs will become reproductives — but let’s not get ahead of the story. The workers not only chew off cellulose (the basic component of wood) to feed themselves, they also have to feed everyone else: nymphs, royals, soldiers. If the initially chosen wood fragment was the size of a fist or maybe a boot, it won’t take more than a few months for the food to run out.

termite control - colony-diagram

Time to look further afield.

Scouts are sent out, usually at night and when a new source is found and pheromones are used to mark the route, a tunnel is built from the original to the new. If the initial fragment is close to the surface the royals are relocated deeper into the soil, seldom do they move far laterally.

The colony always seems under threat. The first hot dry summer can mean lack of moisture and they dry out and die. Or heavy rain can wash the initial fragment away. Then there are bushfires, ants, echidnas, bush turkeys and other wildlife that can also terminate the termites.

Having somehow survived those first 2-3 years, a colony’s chances increase dramatically; they just need more and more food, never relying on just a couple of sources no matter how big it is (tree, log, house). The foraging scouts leave the security of the current workings but once a new food is found, the workers build an impregnable (to ants) tunnel to it. This tunnel may go just below ground level, on top of the ground, up over the edge of concrete foundations and once into the timber, they stay below the surface out of your sight. Once inside a house, all the timbers join up and they can get to anywhere and everywhere, removing tonnes of timber out through that little tunnel… keyhole liposuction!

The queen might live for 25 years or so and by the time she is a 3 yr old, she is probably laying a thousand eggs a day. Her abdomen enlarges to 25-30mm long to accommodate her egg-laying equipment. When she dies or degenerates, she is usually replaced by a chosen reproductive which is spared the flight.

A colony does not begin producing nymphs to turn into reproductives until it is well established — maybe 3-6 years, whenever. If you break open some galleries and see generally browner individuals (with eyes) and usually a little longer in the abdomen, you might on closer inspection see developing wings. Closer to the start of summer, the wings will be getting in their way but they begin clambering toward the highest part of the working galleries where workers will have cut open slots about 20-30mm long to the outside world. The opening will be guarded by soldiers heads until that warm humid evening arrives. I can’t help wondering who yells the termite equivalent of “Geronimo!” as they launch themselves into the evening sky.

You can identify flying termites easily; they are the only insects with all four wings of the same size that they lever off soon after they land. I suggest (if there’s no stormy lightning) you get a torch and look up at nearby trees, poles and buildings to see if you can find them pouring out of a high narrow opening which usually means the actual colony is close by. To prove that termites aren’t always so damned smart, there have been plenty of times homeowners have told me the flight slot was cut in the plasterboard of their lounge room and ten thousand termites made it almost impossible to see the TV!!! No chance of any successful colonisers in that lot!

Termite have instinctive habits to specifically meet their needs.

These few subterranean major pest species need just three things: a constant supply of moisture (found in soil), food (cellulose), and privacy (which means mud tunnels and staying inside whatever they are eating).

As a colony enlarges, so does the demand for moisture. They are very thin-shelled insects and once they are exposed to anything other than their controlled climate of about 80% humidity and 25C+ temperature for any length of time they dehydrate and die. Workers travelling, say up into a warm roof, will chew off their payload of cellulose and head back to earth as soon as they can. If a feeding area of their workings (galleries is another term used) becomes hot, they will wait until it is cooler — another day, or during the night. The significance of this is that if you discover termite damaged wood that appears to be empty, it might be re-occupied when the ambient temperature is more suitable — just leave a small hole and check again next morning or in a couple of days. If the hole has been repaired, it will confirm the gallery is still in use and you can do something about treatment.

Sometimes termites build a re-hydration mass where many kilograms of moist ‘mud’, usually close to their entry point into a house, and especially if the nest is still some way off. Workers and soldiers that have traversed say 30 metres to the building then another 10-15 metres up into warm framing will be happy to rehydrate in a safe, moist staging camp or bivouac before proceeding back to the nest. This ‘mud’ mass is often discovered in the wall cavity between the studs behind the plasterboard.

termite control - town hall

Finding food has produced some amazing termite feats. Here’s my first-hand account of Coptos finding a couple of beams of timber at the top of the bell tower of the Sydney Town Hall in 1958: they had built a long tunnel about as thick as a finger from the upper mezzanine, up past the cogs and workings of the clock, up a sandstone column into the dome where two 400 x 400mm wooden beams bridged the masonry hole and which, by a short metal bar some 200mm diameter, supported the maybe two tonne bell which was struck on the hour. A few weeks/months later, the beams would have been weakened and the bell would have crashed, stripping out the clock on the way down to the foyer. The at-that-time Lord Mayor Harry Jensen would have asked some serious questions!

Privacy to termites means staying enclosed. Workers and soldiers do not have eyes so they can’t see if you are looking at them, however they obviously sense light and want to block it out because an opening represents loss of humidity and the opportunity for invasion from their mortal enemy — ants.

Whenever subterranean termites work above the soil, they remain inside either the tunnels or the timber they are eating and, if there are cracks or splits, they fill up the gaps with a regurgitated food/soil mix. (Scouting/foraging termites are the exception; who knows how many are lost during their patrols?).

When a large part of a termite gallery system is damaged, such as when an echidna, a numbat or maybe a human breaks in, there is usually too much damage to be repaired to quickly restore the gallery to its original safe state. Soldiers guard while workers repair and seal the narrow access tubes closest to the nest. This often results in sacrificing large numbers of workers and soldiers who can never get back. But the nest is secure and the colony can expand again another day in another, often parallel, direction.

We’ve already mentioned the major natural enmity with ants probably highest up their list. Humans become a major enemy too when we put our mind to defending our structures but termite instincts were formed long before humans; we are not recognised! Do not ever think that if your backyard is overrun with ants that you won’t have a termite problem. On the evolutionary timeline, termites have been around longer and they can keep ants out of their galleries. The message here is: don’t put up with invading ants in your kitchen hoping they are at least keeping the termites at bay outside. They aren’t.

Summary

Sorry to keep labouring the point, however, it is because termites stick with their habits that you can anticipate their intentions and use your knowledge and your own ingenuity to defend your home and structures.

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