Xavier Magazine

Beetle Mania: The Hunt for a Different Kind of Longhorn

Like a lot of entomologists, assistant biology professor Ann Ray has been bugged by a dearth of information about the valley elderberry longhorn beetle. So she joined a group of other bug-crazy biologists to find a better way to locate them than just looking in the weeds.

The valley elderberry longhorn beetle, whose Latin name is Desmocerus californicus dimorphus, is a threatened species, just a step below endangered. But there’s a catch—no one really knows how many there are.

“Since (the beetle was added to the threatened species list in 1980), it has been the subject of a lot of controversy because the larvae bore into elderberry trees,” Ray says. “Elderberry is a weed. It just grows up in all sorts of place. Since the beetle’s elderberry habitat is protected, you can’t cut down elderberry trees. But you also can’t develop.”

Property owners don’t like elderberry, but they can’t cut down the pesky weed because it’s the habitat of the longhorn. And yet determining exactly how threatened the longhorn is has been nearly impossible. Until now.

Who would have thought that the sex pheromone desmolactone could be the answer?

Entomologists use pheromones like desmolactone in special traps, where the pheromone is hung in a cross-section of cardboard. The beetles are attracted to the pheromone and hit the cardboard as they fly, falling into the trap. Only the male beetles are attracted to the traps. It’s a far more effective way to find specimens than hunting through elderberry trees.

Ray and her colleagues published an article on their discovery in the online journal PLOS One in December last year and hope it’s the answer to finding—and studying—the valley elderberry longhorn beetle. And maybe freeing up the elderberry for a much-needed trim. Read the journal article at PLOS One.


Xavier Magazine

Beetle Mania: Eradicating Invasive Bug Species

Biology professor Annie Ray clicks her pen, closes her spiral notebook and snaps the trap shut, feeling satisfied with her catch. She’s not exactly sure what kind of beetles are crawling in the Portland warehouse on this spring morning, but she knows that the ones in her trap will bring her closer to saving the world—parts of it, at least.

When Ray’s not on campus, she’s probably not at home or on vacation, either. In fact, she likes to keep busy on her days off. Ray, who has a doctorate in entomology (that’s the study of bugs), spends her extra time partnering with customs agents and the U.S. Department of Agriculture to understand how invasive insects, specifically the longhorned wood-boring beetle, thrive in foreign habitats. Basically, international pest-control.

Not much is known about the beetles that Ray studies. What scientists do know is that there are an estimated 35,000 species of longhorned wood-boring beetles, and that they’re found on all continents except Antarctica. What scientists don’t know is how the different species of longhorned beetles affect individual ecosystems. That’s where Ray’s research comes into play.

“Invasive insects have huge impacts on ecosystems and land values,” says Ray, citing the Asian longhorn beetle infestation in North America as an example. First spotted in New York City in 1996, the beetle, which is native to Asia, has now spread to states as far away as Illinois and Ohio. Left unmanaged, the infestation could result in more than $650 billion in damages to forestry and landscape, according to a recent report commissioned by the USDA.

Ray’s work begins when the USDA receives a report of a foreign beetle infestation. With the report in hand, she travels to nearby offloading warehouses and sets traps using pheromones, which are chemicals beetles release to attract potential mates. She then records how the beetle populations grow, eat and reproduce in their new habitats. Scientists use her research to compile databases that help them quarantine and eradicate invasive bug populations.

According to Ray, the longhorned wood-boring beetle’s trip abroad starts when goods like auto parts, tiles and furniture are packed into fresh-cut wood crates for overseas shipping. Wood-boring beetles eat, reproduce and burrow in trees, so many of them end up hitching a ride with the wooden crates. When the beetles arrive in the states, they crawl out of their burrows and start looking for a fresh-wood meal in their new habitat.

“The truth is that we just don’t know what we’re up against,” says Ray, after returning home from a trip to Portland. “There isn’t much data that associates larvae and beetles in their adult stages. So when a warehouse worker finds a larva burrowed in a crate, we’re not sure what kind of longhorned beetle it will turn into. I collect DNA samples from the larva for barcoding purposes and identify the types of wood that are likely to house certain species of wood-boring larvae.”

The work is demanding, but for Ray, it’s not all about getting rid of pests: Her time spent outside the classroom also includes research on the conservation of endangered beetle species, like the Valley Elderberry longhorned beetle, a species native to the Central California region.

Similar to her work with pest control, Ray uses phermones to study the endangered beetle populations. And she is the proud owner of 11 pet tarantulas who also reside in a foreign habitat—her office.

Ray, who participates in the biology department’s annual Costa Rica study abroad experience, says she wishes that her students could experience field research with her more than just once a year. Hands-on research, she argues, is necessary for the development of the whole self.

“A liberal arts education makes you a better scientist, but it also makes you a better person as well,” she says. “It’s so nice to watch the students interacting with the outdoors and experiencing the world. They just blossom and turn into different people out there.”