Every year as we enter storm season here in Brisbane, the trees around our properties can become more of a concern, especially when two of the most vicious local termite species are involved.
Most trees are an asset; providing shade, cleaning the air, sheltering local wildlife. Some bountiful species provide us with special treats like mangoes and macadamia nuts. Trees also provide us with a very remarkable building material: wood. Light and strong, humans have used this excellent resource for thousands of years. Wood is also very durable and difficult to biodegrade. Special niche organisms developed to unlock nutrients trapped in the wood, such as decay fungi, auger beetles, and of course termites.
Are all termites very destructive?
No, not all termites are very destructive, so you need to know your enemy and where they live. Some local species of termites damage wood and their host trees relatively slowly. A classic example of this would be Microceretermes spp. The bulky tree nest, while visually spectacular, hides only minor damage to the trunk behind it. A close examination of the rest of the tree should only reveal shallow, shallow mud tubes (unless another species has been working). Unless they are particularly troublesome or very close to your home, we generally recommend leaving them alone (the nest may be used by other wildlife in the future).
So which termites should we worry about?
This boils down to our most common suspects, Coptotermes and Schedorhinotermes. Both types are a massive threat to your home and are the termites most commonly associated with serious structural damage. They are also capable of nesting similar to each other, and do so frequently. You will often find them inside live and dead gum trees and stumps, and their nests are not as obvious as those of Microcerotermes spp. You have to know where to look for these guys and it can take a bit of a raid to find them.
How do termite nests start?
Initially, king and queen termites (alates) burrow at the base of the tree or in and around the root crown. As the colony grows, more space is required. Now provided with worker termites, the queen sends them to hollow out the tree trunk, gaining food and more space to live. Soon the trunk will be seen full of termites, although at first glance it seems intact. In this way, large amounts of structurally important wood can be removed, significantly weakening the host tree. An event like “Oswald” arrives (the former cyclone we had in January 2013) or a strong storm (like the one in Gap a few years ago) and suddenly everything collapses. Badly damaged trees may only require a gusty breeze. Remember that the damage can continue for many years, and just because it didn’t fall last time doesn’t mean it won’t fall next time.
How are termite infested trees treated?
Treatment of infested trees usually involves drilling into the trunk at various angles and identifying the cavity made by the termites. The important nursery (where the queen lives) can be identified by its elevated temperature. Liquid termiticide can then be administered directly to this area. Often the damage to the tree can be extensive and the tree may still need to be removed for safety reasons.
If you suspect a tree in your yard is hiding more than you’d like, contact a termite specialist and have them take a look. It’s best to remove these pests before they cause too much damage!