Will Wetzel in the field
As unsexy and pesky as they may be, Will Wetzel loves flies. They are the main subjects of his research project, which he hopes will further the understanding of how animal populations change over time.
“I started with a bunch of projects, but this one was the most exciting,” Wetzel said with a grin, while gently trying to nudge one of the species onto his finger.
A graduate student at UC Davis, Wetzel has been conducting his research in Mammoth’s own backyard, at the Valentine Reserve. The flies, Eutreta diana, eat and are eaten in the complex circle of life that Wetzel has had his sights on for three years, and expects to closely monitor for at least three more.
“In brief, I’m studying an insect food web that has sagebrush as the primary producer,” Wetzel explained. “The main herbivore in the food web is a fly called Eutreta diana. It feeds on sagebrush as a larva from inside small swellings in sagebrush stems called galls. The larvae of the fly trick the plant into forming galls by releasing growth hormones. The larvae then crawl around inside the galls and feed on the plant tissue from the inside out.”
Female flies through ovipositors, or long needle-like appendages, deposit the larvae. When it is time for the larvae to spread their wings, they tunnel their way out of the gall.
But it’s not always smooth sailing for the Eutreta diana. Predators such as parasitic wasps, beetles, ants and even songbirds love to feed on the larvae, hence the tangled food web Wetzel has woven, which is not always a pretty sight.
The most specialized predators are parasitic wasps that also have ovipositors that they use to drill into the galls and deposit eggs, Wetzel said. The wasp eggs get inside the fly larvae where they hatch, feed on the insides of the fly larvae, and then burst out of the baby flies when ready to fend for themselves, killing the fly larvae in the process (think about that scene in the movie Alien).
While, according to Wetzel, there is no threat of the Eutreta diana dying off, some of its predators do rely solely on the fly as their food source and would become extinct without the little buggers, proving that the lowliest piece of a food web is often the most important.
So what does science like this mean for the rest of us, besides fodder for our favorite horror flicks?
“We are judged by our use and the publications that are produced
from research here,” said Valentine Reserve Education Coordinator Leslie Dawson. “People come in and see the wildflowers, wildlife, etc. but what we are really about at the Reserve is research.”
Which is why the Reserve remains so protected. The controlled environment it provides can’t be beat when it comes to experimentation.
“There is sagebrush all over the Great Basin,” Wetzel explained. “But here, the sagebrush is ungrazed,” which means one less variable that Wetzel has to account for in his work.
Even national parks and public lands, which are protected in certain aspects, are still fully open to the public.
“The gold standard in science is experiments,” Wetzel explained. “The facilities to do experiments aren’t available at national parks or on federal lands.” As an example, Wetzel pointed out his open-air experiment for the sagebrush and the flies. At Valentine he can rest easy knowing that the large enclosures he has set up around the Reserve won’t be bothered by anyone or anything other than bears. He wouldn’t be so confident if the enclosures happened to be set up on BLM land.
“People are curious,” he explained.
Since experimenting in national parks and public lands isn’t realistic, those agencies use the knowledge discovered at reserves such as Valentine for management of those lands, according to Wetzel and Dawson. Data collected from places such as Valentine goes directly to land managers to be incorporated into their policies.
Sharing cutting-edge research with larger land management agencies is not the only educational outcome that is the result of work done at Valentine. Wetzel himself teaches local Eastern Sierra students about ecology and experimentation as part of his work on the Reserve, sharing his knowledge directly with young, budding scientists.
Gone are the days of scientists working clandestinely behind closed lab doors, not explaining their research to the public. In order to truly be competitive, scientists must incorporate teaching and outreach in with their research.
“Teaching classes is part of the broader outreach that is important to scientists these days,” Wetzel said. “We have to educate the public to let them know why money should continue to be spent on science.”
In some ways you could say that Wetzel chose the perfect subject to study at the Valentine Reserve. Just as the flies are the bottom feeders in a complicated food web, the Reserve is the first rung of an educational ladder that spreads all the way up through federal agencies. Without the flies or places like Valentine, the higher ups would cease to exist.
