How to determine the difference between Drywood and Subterranean Termites

Termites cause some of the worst structural damage in the United States. According to some estimates, over 5 billion dollars is spent annually controlling and repairing termite infestations and damage. Subterranean termites play a big role in that annual cost, estimating between 1 and 2 billion dollars spent annually. Termites work 24 hours a day without ever taking a break, no matter what species. Studies show that termites have been able to survive for over 250 million years. The highly structured nature of the colonies allows termites to adapt to the ever changing environments around them. Both types of termites eat cellulose for nutrition. Cellulose is found in wood and wood products. Unfortunately termites do not distinguish the difference between the wood in your home and the wood in forests, to satisfy their nutritional needs. So with that being said, it’s a good idea to know what species of termites are present and have them eradicated right away!

Here in San Diego the two most common types of termites are drywood and subterranean. Termites are identified by the appearance of the swarmers, damage, and the droppings they leave behind as well as some other key points that we will mention in this article.

Drywood termite soldiers and workers are much larger than the soldiers and workers of subterranean termites. The appearance of swarmers in drywood and subterranean termites are important for identifying the difference between the two species. Drywood swarmers, have two sets of wings. The outer part of the front set of wings has a pattern of three or more, well-pigmented veins. Drywood swarmers have red heads and black bodies where subterranean termite swarmers are solid black.

Photo: Subterranean Mud Tube

One distinct way to tell what type of termites you have on your property is “Mud Tubes,” also known as tunnels. These are literally mud formed into the shapes of tubes created by the workers. These allow subterranean termites to safely travel around the property and up into the structure of your home. Subterranean termites need moisture to survive and will die if exposed to sunlight or open air. These tunnels protect them from the outside elements, predators and also help keep them hydrated. Now just because subterranean termites need moisture to survive, that does not mean they will only stay in the soil beneath your home. If you have a leak in your roof, the subterranean termites will build mud tubes all the way up into that leaking area to feast on the surrounding wood. Subterranean termites can gain access from small cracks in the slab floor or even though small openings around the perimeter of your home. When looking around your home for subterranean termites, inspect areas that are prone to high moisture conditions, like basements, crawl spaces or anywhere you find soil to be damp or standing water is often present.

Photo: Drywood Termite (Worker) Velvety textured wood

Now on the other hand drywood termites nest inside the wood they are infesting and do not need any sort of contact with soil to stay hydrated. They get enough moisture to survive from the cellulose they eat. This leads to varying points of attack on your home. Common entry points would be attic vents, fascia boards, rafters, window seals, door jambs, and your garage. Once in, drywood termites can infest virtually any part of your home.

Each species of termites have different eating habits.

Photo: Drywood termite Droppings

When drywood termites feast on wood they leave a velvety texture and subterranean termites leave a smooth surface. You can also detect what type of termite is present by their droppings/ fecal pellets left behind. Subterranean termites use a mixture of their droppings and soil to line and create their mud tubes. Because of this it is less likely you will spot subterranean droppings. Drywood termites create ‟kick-out” holes to push their droppings through. This leads to their distinctive droppings piled where ever they are in your home. These fecal pellets often resemble coffee grounds though they may also mimic the appearance of sawdust or sand. Termite droppings vary in color depending on the type of wood/other cellulose food source, ranging from beige to dark brown. Sometimes fecal pellets can even be black.

If you suspect you have an active infestation of either drywood or subterranean termites call a licensed company like us and have a licensed inspector come out and identify which type of termite is present and your options for treatment.