John Moser’s Research on Town Ants and Mites

The aboveground view of a town ant colony. Photo by U.S. Forest Service, courtesy of

On December 31, 1989, John Moser retired from the U.S. Forest Service Southern Research Station (SRS). The next day, he was back as a volunteer to continue his research on insects. Today,  over 20 years later, he still works daily and most weekends. 

“John Moser has become an international authority on town ants,” says James Barnett, also SRS emeritus scientist and lead author of a new general technical report, Town Ants: The Beginning of John Moser’s Remarkable Search for Knowledge. The report describes Moser’s career, background, accomplishments, and the significance his half-century of work at the SRS Insects, Diseases and Invasive Plants unit.

Moser once seemed an unlikely scientist. “My scholastic record in high school was less than spectacular,” he says. In his sophomore year of college, however, he discovered a previously unknown species of gall wasp—and a lifelong interest in forest entomology. Once Moser found his niche, he never lost interest in the small worlds of ants and beetles, the miniscule mites that live on their bodies, and the microscopic fungal species that live alongside them both.

When Moser began working at the Station in 1958, his first assignment was to develop control methods for town ants. Also called leafcutter ants, the species are the farmers of the insect world, growing fungus in underground cavities called gardens. The fungus is the ants’ only known food, and because the gardens must be supplied with fresh leaves, the ants defoliate young plants, and as Moser says, “can strip a newly planted pine plantation naked of every needle.”       

His approach to the town ant assignment went beyond control strategies. “Moser’s long-term goal was to develop a better understanding of the ant’s biology,” says Barnett. Moser was one of the first researchers in the U.S. to excavate and map a town ant colony, and he also discovered several undescribed insect species that lived alongside the ants without causing harm.

Moser’s research on town ants established him as an expert in town ant biology and led to a career-long interest in town ant ecology and that of its interrelated species. Although his involvement in the town ant project officially ended in 1962, he continued publishing earlier research on town ants, and his collaboration with university partners led to the discovery of new trail-marking compounds and bioassays that are still used today.

In addition to town ants, nematodes, and fungi, Moser studied southern pine beetles and the mites that live on their bodies. “Moser continues his efforts to understand the relationships among these insects,” says Barnett. “Mites can spread tree diseases, and Moser’s research has led to new opportunities for understanding how tree diseases can spread through our forests.”

Access the full text of the GTR.

For more information, email James Barnett at

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