ST. GEORGE — Record-breaking moisture may have caused an increase in cockroach sightings this year, but there is good news: Roaches slow down as temperatures drop, giving locals until next spring to prevent infestations.

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“This was a very unusual year,” said Hannah Brenchley, area manager at EnviroGuard Pest Control. St. George received almost double its average rainfall, which may have prompted roaches to move indoors to escape flooding and heavy rains.

“This could be why people are seeing an increase inside their homes,” Brenchley told St. George News.

While there are thousands of cockroach species across the globe, four are considered pests in Utah: the German, American, oriental and brown-banded cockroaches.

The increase in sightings was most notable in German cockroaches, which Brenchley said are challenging to eliminate as they are smarter and multiply more quickly than other species.

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“The German cockroach is the cockroach of concern, the species that gives all other cockroaches a bad name,” according to the University of Florida’s Featured Creatures.

German cockroaches have colonized areas across the globe near human populations and are typically found in multifamily dwellings, the university states. The species is unable to survive away from people. Factors inhibiting their spread include cold temperatures and the availability of water, food and shelter.

Cockroaches can cause allergic reactions in some people and can worsen asthma symptoms, according to the American Lung Association. The insects can leave body parts, saliva and fecal matter in their wake, creating small particles that can become airborne or settle into fabrics.

“The most common way to inhale cockroach allergen is to breathe in dust that has collected in pillows, bedding or other dust-trapping fabrics,” the association states.

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Roaches also have a reputation for having “dirty habits,” according to Utah State University Extension.

Most house-dwelling cockroaches hide and reproduce in warm, humid places like sewers and garbage receptacles,” the extension writes. “From these areas, they can pick up food spoilage organisms and human pathogens. At night they come into areas where food and water are accessible, like the kitchen and bathroom, and spread diseases they carry on their body or via defecation or regurgitation.”

Additionally, according to Bulwark Exterminating, roaches have a pungent odor.

“Describing the cockroach smell isn’t easy,” the company states. “Most of the time you won’t smell it until the population size is quite large. But if you have the unfortunate chance to deal with multiple infestations, you can pick up that scent with only a few roaches present. Yes, pest control pros are among that small percentage that can smell roaches. No, it is not a superpower. Quite the opposite. Sadly, this skill has ruined a restaurant meal or two for some exterminators that pick up that scent halfway through dinner.”


Most infestations occur in the spring and summer as higher temperatures prompt the insects to seek refuge inside, Brenchley said.

“April showers bring more flowers but also roach infestations,” she said.

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Insects are coldblooded, so infestations decrease in cooler temperatures, according to American Pest. Those that don’t die, such as cockroaches living in homes, slow down and multiply less quickly.

“When temperatures warm up again, those cockroaches that have been laying low for the winter will suddenly go into high gear, searching for food sources and multiplying like crazy,” the company states.

Homes with poor drainage systems or various roach entryways, such as holes in walls or cracks in screens, are more likely to become infested. Brenchley said the bugs typically nest in moist areas, and the company often sees infestations beginning in kitchens and bathrooms, particularly under sinks or behind appliances.

To prevent infestations, Southern Utahns should eliminate cockroach entry points, such as under doors, through cracks in foundations or via pipes, among others. Utah State’s extension service suggests sealing all entryways and hiding places greater than 1/16 inch with silicone caulk, installing door sweeps and weather stripping on doors and windows, and clearing clutter. All items that have been in roach-infested areas should be inspected before they are taken inside.

“Cockroaches need moisture, food,and shelter to survive,” the extension states. “Cleanliness and attention to minimizing available moisture and food sources are critical aspects to any cockroach management program.”

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There are various ways to make a home inhospitable to cockroaches. For instance, homeowners can repair leaky fixtures, pipes and drains; dry sinks, baths, dishes and other wet areas with a towel after each use; avoid storing moist dish rags and sponges where bugs can access them; and store food in airtight, plastic containers.

To manage cockroach infestations, Utah State suggests integrated pest management — using multiple control tactics simultaneously. The method includes identifying the species of cockroach, monitoring, altering the environment and using various control methods, such as baits and insecticides.

Some cockroaches may be resistant or have learned to avoid control methods and “using only insecticidal tactics will not likely eliminate your roach problem,” the extension states, adding that using a combination of strategies is most effective.

In some cases, homeowners may benefit from outside help.

“If you notice the problem getting out of control, it is always nice to take something off your ‘to-do’ list,” Brenchley said. “Pest control shouldn’t be something that you have to worry about. If it is interfering with how you are living your life or you would just like peace of mind, call a pest control company.”

What good are roaches anyway?

Cockroaches are beneficial to the environment. They consume organic matter and assist with natural decomposition processes. They “play a crucial role in the nitrogen cycle, supporting the health of forests,” Bulwark Exterminating writes.

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Additionally, this 2022 study funded by the Air Force Office of Scientific Research suggests that while continued study is needed, cockroaches could benefit humans.

As “one of the hardiest insects,” they can survive for up to 30 days without food and 45 minutes without air, and they “thrive in unhygienic environments,” the study states.

One reason for this could be cockroaches’ gut microbiome or the metabolites produced by their natural bodily processes, like digestion.

The researchers state that this could lead to discovering biologically active molecules that could be used to treat infectious diseases and cancer, citing the insects’ success and their “extensive use in traditional and Chinese medicine.”

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