Apr 25, 2011 – The Termite Appetite
QUESTION:
I'm familiar with how much wood over a period of time subterranean termites can eat, but I can't find anything on how much wood drywood termites can eat. Can you help please?
ANSWER:
I looked through some references on termites and frankly couldn't find any specific numbers put to this. So, the best I can offer is some comparison between the two kinds. Subterranean termites cause more damage than just the eating, as they tend to encourage moisture in the wood and this leads to decay fungus problems as well. But, ultimately both kinds of termites are capable of eating ALL the wood available to them. As it states in my Mallis book, drywood termites will eat every bit of the wood and leave just the paint behind, and we have all seen wood fed on by subterranean termites, where all that may be left is the harder "rings" of the wood.
The difference may be in how fast this can occur, and this is a function of colony size. Some subterranean species can have colonies that max out at several hundred thousand workers, and of course the Formosan may have over a million workers in a colony. This represents a lot of little mandibles chewing off pieces of wood in a structure, so the damage from subs occurs quickly. I have heard from friends in Hawaii that a home may be so destroyed in just 6 months from Formosan termites that it is more economical to tear it down and rebuild than to try to repair all the damage. Drywood termite colonies may max out at just a few thousand workers, and typically in the western drywood a colony after 15 years of that colony's existence there may be only 2700 workers in it. The queen just lays fewer eggs and the colony grows more slowly than the aggressive sub termites, where a queen could be laying 1000 eggs each day once the colony is well established.
Both kinds of termites will feed on virtually any species of wood, but drywoods cause us a problem because prevention is very difficult. We can keep subs out of a structure with a proper soil treatment or pretreating the wood with a borate, but drywoods may just fly into an attic and infest wood with no chemical barriers to stop them. Fortunately the range of drywoods is far less than that of subs, so much of the U.S. is without drywood termites. Looking around on the internet is always risky, because you can find a lot of opinions that may or may not be based on facts. However, one website stated that a sub colony of half a million workers will consume the equivalent of a 2 foot long 2x4 each year. Personally, that seems like a great under-estimate to me, but maybe it's accurate. Formosans, according to this website, consume 6 times that amount, and that definitely seems like an understatement.
So, I'm limited to comparing, and I would suggest that Subterranean termites can do substantial damage within just a few years of feeding within a structure, whereas Drywood termites might be there for 20 years before serious structural weakening occurs.
I'm familiar with how much wood over a period of time subterranean termites can eat, but I can't find anything on how much wood drywood termites can eat. Can you help please?
ANSWER:
I looked through some references on termites and frankly couldn't find any specific numbers put to this. So, the best I can offer is some comparison between the two kinds. Subterranean termites cause more damage than just the eating, as they tend to encourage moisture in the wood and this leads to decay fungus problems as well. But, ultimately both kinds of termites are capable of eating ALL the wood available to them. As it states in my Mallis book, drywood termites will eat every bit of the wood and leave just the paint behind, and we have all seen wood fed on by subterranean termites, where all that may be left is the harder "rings" of the wood.
The difference may be in how fast this can occur, and this is a function of colony size. Some subterranean species can have colonies that max out at several hundred thousand workers, and of course the Formosan may have over a million workers in a colony. This represents a lot of little mandibles chewing off pieces of wood in a structure, so the damage from subs occurs quickly. I have heard from friends in Hawaii that a home may be so destroyed in just 6 months from Formosan termites that it is more economical to tear it down and rebuild than to try to repair all the damage. Drywood termite colonies may max out at just a few thousand workers, and typically in the western drywood a colony after 15 years of that colony's existence there may be only 2700 workers in it. The queen just lays fewer eggs and the colony grows more slowly than the aggressive sub termites, where a queen could be laying 1000 eggs each day once the colony is well established.
Both kinds of termites will feed on virtually any species of wood, but drywoods cause us a problem because prevention is very difficult. We can keep subs out of a structure with a proper soil treatment or pretreating the wood with a borate, but drywoods may just fly into an attic and infest wood with no chemical barriers to stop them. Fortunately the range of drywoods is far less than that of subs, so much of the U.S. is without drywood termites. Looking around on the internet is always risky, because you can find a lot of opinions that may or may not be based on facts. However, one website stated that a sub colony of half a million workers will consume the equivalent of a 2 foot long 2x4 each year. Personally, that seems like a great under-estimate to me, but maybe it's accurate. Formosans, according to this website, consume 6 times that amount, and that definitely seems like an understatement.
So, I'm limited to comparing, and I would suggest that Subterranean termites can do substantial damage within just a few years of feeding within a structure, whereas Drywood termites might be there for 20 years before serious structural weakening occurs.
