Carpenter ants are notorious for causing damage to properties but is their reputation based on fact or fiction? Jay Turner examines the evidence.
I have always had an issue with the common names given to species. They can often be misleading or used very loosely to describe multiple species. A very well known example of this is the king brown snake (Pseudechis australis), which is actually a member of the black snake family, and is more closely related to the red-bellied black snake (Pseudechis porphyriacus) than the eastern brown snake (Pseudonaja textilis).
The carpenter ant is possibly even worse. Over the years I have heard the name ‘carpenter ant’ applied to basically any member of the Camponotus genus as well as any ant found nesting within timber. Where did the name ‘carpenter ant’ come from and is it even appropriate?
The reality is the name carpenter ant actually applies to a handful of Camponotus sp. in the United States, with the black carpenter ant (C. pennsylvanicus), western black carpenter ant (C. modoc), bi-coloured carpenter ant (C. vicinus) and the Florida carpenter ant (C. floridanus) being the main ones. These species can reach 50,000-100,000 individuals in a colony and can cause significant timber damage, and are classed as a WDO (wood destroying organism). But should the reputation of these few species be applied to all Camponotus sp.?
A quick Google search for ‘carpenter ants’ shows why it’s no wonder there is such a hype about these ants, even in Australia. Statements like ‘major cause of structural damage’ are common on popular sites such as Wikipedia and on company websites. There’s even the claim that ‘carpenter ants are one of nature’s most aggressive wood destroyers’ on another website. It seems that some companies think that scare tactics are a good marketing strategy.
A recent survey on the very popular Australian Pest Managers’ Network Facebook page revealed that Australian Camponotus species cause very little timber damage and the consensus among pest managers is they are a secondary pest to true timber pests such as fungal decay.
Surely the reputation of these ants isn’t based upon media hype alone? The reason for their reputation probably lies within their behaviour. Many Camponotus sp. favour fungal decayed wood, where they will excavate the soft timber within to create their nest. Often this decayed timber is chewed right back to clean, sound timber, giving the impression that the ants have ‘eaten’ the wood. Another common misunderstanding is the ants’ tendency to occupy old termite galleries and workings, once again giving the impression that the ants have caused the timber damage. It’s no wonder many ants are falsely incriminated and incorrectly labelled ‘carpenter ants’.
Worldwide there are over 1400 species of Camponotus, with Australia having 143 of those described species, including the famous desert honey-pot ants (C. inflatus). Other well known Camponotus species include the banded sugar ant (C. consobrinus) and the household sugar ant (C. humilior). Carpenter ants are typically nocturnal and one of the few ant species which are polymorphic, meaning having multiple-sized worker castes. The minor workers are food gatherers and are encountered further away from the nest whereas major workers stay closer to the nest and defend it. Camponotus ants feed on both carbohydrate and protein-based foodstuffs.
The key to successful treatment of Camponotus ants is the inspection; being a nocturnal ant, this means night times are often best. Camponotus ants will often have several satellite nests so it is often a matter of taking the time to locate these nests and directly treating the nest with an insecticidal dust or aerosol.
Unlike their American cousins, most Australian Camponotus ant nests are relatively small with nest sizes normally numbering less than a few hundred individuals, so typically requiring very little insecticide application. Lightly using a dust or aerosol as a flushing agent can also be an effective way of locating nests or, if you are patient and have the time, feeding foraging ants chopped up insects or cake crumbs and following them back to the nests. Failing that, residual liquids will help reduce foraging ant numbers.
So, the question remains: are our Australian Camponotus ants be deserving of the common name ‘carpenter ants’? Or should we, as professionals, adopt the Australian Museum term of ‘sugar ants’? Perhaps this is just another misleading common name. I personally prefer to use the term Camponotus, but I’ve always been a bit of a stickler for trying to be technically correct.
Jay Turner, Laguna Pest Control