Research Stories

by Margaret Coulombe

Once a year, ASU scientist Stan Faeth's experimental site at the Arboretum in Flagstaff gets a thorough spring cleaning. The cleaning tool of choice is not a Hoover. It's not a Dyson. And it's not a Dirt Devil. Faeth and his team prefer the bug vac.

The bug-vac is officially known as the "Vortis Insect Suction Sampler." The machine is made by Burkard Manufacturing Company Ltd. in England. It uses a motor that operates much like that found in any leaf blower. But it is designed to suck up bugs into a sample cup. The cup is emptied following collection from each plant.

"We vacuum each fescue and every sleepygrass plant in May," says Sally Wittlinger, Faeth's lab manager and field expert for more than four years.

The bug vac sucks arthropods from the fescue or sleepygrass. They plop softly into a sample cup. The little creatures are then emptied into a jar filled with 70 percent ethanol. The solution preserves the insects, spiders, and other arthropods with minimal damage.

Faeth's undergraduate workers in the School of Life Sciences get the fun job. They sort the ethanol-preserved arthropods from the debris. The catch is divided into groups. Spiders go with spiders. Thrips go with thrips, mites with mites, springtails with springtails, and so on.

Andrea Cloudcroft puts the bug-vac in action.

When the sorting is complete, it is research specialist Maggie Tseng's job to identify each of the insects and other arthropods. She categorizes them by Family or Genus. Each critter is assigned to what Faeth calls a "feeding guild." There are detrivores, herbivores, omnivores, parasites, and predators.

The ASU researchers analyze each feeding guild in lots of ways. For example, they look at each little creature in relationship to its genotype, or genetic makeup. They also look at the creature's relationship to the infection status of the plant. Does the plant have endophytes, or not?

Each new bit of information is important. Every bit adds to the continuously growing body of knowledge.

Read more about Stan Faeth's research in "Symbionts and the city."