Ask The Expert

MICHAEL BENTLEY, PhD, BCE, Director of Training and Education, NPMA

Q My client is complaining of medium sized reddish brown, torpedo shaped beetles. They congregate around the porch light and occasionally find their way inside. What are they?

A The pests in question are commonly called click beetles (family Elateridae). There are more than 900 species of click beetles in the U.S. and none are structural pests—meaning they will not breed, overwinter or otherwise infest a structure—but many species are pests in agriculture. The larvae of pest species are called wireworms and can destroy roots of important crops like corn, tobacco and wheat. Adults are commonly attracted to lights, sometimes in large numbers. This is probably what your client is experiencing. Turning off the porch light, changing to a less attractive bulb, or using alternative lighting placed away from the door might help reduce the number of beetles getting inside the building.

One of the amazing things about click beetles (and the reason for their strange but descriptive name) is they will initially play dead when disturbed, but eventually (and when you least expect it) they will catapult themselves into the air with an audible "click." This behavior is intended to startle and confuse predators, helping the beetles escape becoming a meal for a hungry insectivore. Scientists have measured the force by which the beetles launch themselves into the air at 380 times the force of gravity.

Q My clients keep asking me about the Joro Spider. Is it something I should be concerned about as a pest management professional?

A The Joro Spider (Trichonephila clavata) is an orb-weaver spider that originally hails from Asia (specifically Japan, Korea, Taiwan and China). They can be up to three inches long, and are brightly colored with stripes of red, yellow and blue. This spider was actually first documented in Georgia back in 2013 and has quickly spread to South Carolina. Experts believe the species was transported via shipping containers. It is expected that the Joro spider will likely naturalize to the East Coast of North America, given that the species has a good tolerance for cold weather and a penchant for accidental transport.

It is not expected that the Joro Spider will become a common household pest. However, the impacts of this invasive spider on local ecosystems are still to be determined. The Joro Spider is not considered to be an aggressive species, and the rare bites are not considered to be medically relevant to humans or pets. Scientists are still attempting to document the spread of this spider, so if you spot one, report it to your local extension office. If an infestation occurs, removal of webs and spiders through vacuuming and eliminating potential harborages can be effective with this type of spider.

Q I’m struggling to control a small fly infestation in my customer’s bathroom. The flies are often seen around the base of the toilet and near the shower drain. I assumed they were phorid flies, but I’m not having any success with the traps I usually use to target this species. Any ideas?

A It’s possible you are dealing with another common small fly associated with bathrooms, the drain fly. This group of flies is also commonly called moth flies because of their fuzzy, moth-like appearance. As their name implies, drain flies are often associated with drains that contain a buildup of organic matter. The standing water and organic matter found in poorly functioning drains creates the perfect breeding site and larval habitat for these small pests to thrive.

Luckily, controlling drain flies is relatively simple once you know where to look. As is the case with other small fly infestations, eliminating the larval food source will resolve the infestation. In this case, the food source is the organic matter building up in one, or more, of the bathroom drains. You can cover the drains with clear tape to isolate the affected drain(s) that need to be treated. Once the breeding sites have been confirmed, you can use a wire brush to break up and clean out the organic buildup. A bio-enzymatic product can also be helpful in removing any debris that may be harder to reach. Lastly, you can mechanically remove any adults that may be lingering in the bathroom. They aren’t strong fliers so they should be easy to target. Good luck!