Bug of the Week: Desert Encrusting Termites

Did you figure out the mystery insect from last week?

The patches of mud you see on the trunk of the saguaro are made by desert encrusting termites (Gnathamitermes sp., probably Gnathamitermes perplexus).

These desert termites build layers of mud on the bases of saguaros or palm trunks. They also plaster mud over dry grass or twigs on the ground, particularly after a rain.  Over time they eat the grasses or twigs, leaving a hollow tube of dried mud.

On trees, they gently scrape the surface clean of dead material.

Desert encrusting termites are different from other termites because they do not enter or eat sound, strong wood. They could even be considered beneficial. Have you ever heard that termites have protozoa in their guts to help them digest the cellulose in wood? Desert encrusting termites have bacteria instead. Those bacteria are capable of fixing nitrogen, which means they actually fertilize the soil. Because the termites work on dry grass and twigs on the ground, they reduce fuel for wildfires. Finally, by tunneling in and moving soil, they aerate it, making it better for plants.

You could say that desert encrusting termites are part of nature’s clean up crew.


  1. Joel Cosmano

    I like the info that you have, it has given me a start on learning more about them. Please send me more

  2. Roberta

    You might want to try this article at the AZ-Sonora Desert Museum https://www.desertmuseum.org/books/nhsd_insects_saguaro_new.php

  3. Frederick C Fritz Fisher

    Thanks, this is something I have noticed but not been sure of. I came here from a book I bought that was advertised on your blog by Michael Moffett. He mentions termites on page 19: Elsewhere in the Western Ghats of India, I saw this system used by Leptogenys. The tight pack of slim, glossy ants was moving through the dry litter at the reckless speed of an Indian bus driver. I followed and watched as they entered the mud galleries of a termite colony. The ants soon emerged, each with a stack of termites in her jaws. This regimented form of group predation

    Moffett, Mark W.. Adventures among Ants (p. 19). University of California Press. Kindle Edition.

    So I decided to check again for information about the tubes on the soil in my study areas.
    Thanks for telling me what I needed and wanted to know.

  4. Roberta

    Thank you for the story.

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