esa researchW

Caroline Larsen examines a dragonfly collected during a taxonomy class field exercise. Courtesy photo

UC Davis

Science matters: Invasive flies fly under the radar

By From page A1 | August 13, 2014

Editor’s note: The Enterprise is highlighting some of the young UC Davis researchers who will be presenting at this week’s Ecological Society of America’s annual conference in Sacramento.

One of two families of fruit flies, Tephritidae can wreak havoc in an orchard. Adults burrow into ripe fruit, flowers, leaves or stems to lay their eggs. When they hatch, the larvae emerge, they gnaw through the plants or fruit, destroying the crop. So it comes as no surprise that the California Department of Food and Agriculture carefully tracks the family of invasive species.

“In California, it’s especially a big deal because of our huge agricultural industry,” said Caroline Larsen, an entomology Ph.D. student at UC Davis.

Tephritidae differ from the domestic fruit flies, like the ones found floating around brown bananas or soft mangoes.

“They have different wing patterns; a lot of invasive species have zebra stripes, so they can be really colorful little flies,” Larsen said. “They’re really beautiful.”

But with one exception, information collected about the 17 species detected in California make the flies seem almost benign.

“The data makes it look more like a rare species,” Larsen said. “(They) don’t really fit with our current idea of what invasive species do. They’re not booming out of control.”

Invasive species are generally lumped together as aggressive and unwanted, especially when they put whole industries at risk. But Tephritidae don’t seem to act the same way as most invasives: The flies simply haven’t invaded. Larsen and her adviser, James Carey, use the data collected by the Department of Food and Agriculture to discern patterns of reproduction and spread to assess the risk fly species pose to California’s heartland.

Only one species, the olive fruit fly, has established a dangerous population in the state. It destroyed crops in Napa and Sonoma last year, though the heat prevents the olive fly from carving out territory in Yolo County.

Beyond the identifying controls for fly populations, Larsen is investigating how information that wasn’t collected for science can be used to enhance research. Working with a government department has opened a world of data to Wright and her adviser — 60 years of detailed reports.

“The question is are they small because they are controlled, or because they are staying naturally low by themselves?” Larsen asked.

Next, she will begin modeling different policies and control tactics to see how they affect fly populations, and what the state actually needs to do to keep them in check.

“It’s like a big mystery game,” Larsen said.

— Reach Elizabeth Case at [email protected] or 530-747-8052. Follow her on Twitter at @elizabeth_case

Elizabeth Case

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • Special Publications »

    Use of this site constitutes acceptance of our Terms of Service (updated 4/30/2015) and Privacy Policy (updated 4/7/2015).
    Copyright (c) 2016 McNaughton Newspapers, Inc., a family-owned local media company that proudly publishes the Daily Republic, Mountain Democrat, Davis Enterprise, Village Life and other community-driven publications.