Untamed Lowcountry

Yuck! When winter comes, palmetto bugs have to go somewhere. Maybe even your home

6 easy ways to rid your home of Palmetto bugs — and how to keep them out

Palmetto bugs, or American cockroaches, are known to invade coastal South Carolina homes. Here are some quick tips from the University of Florida's Institute of Food and Agricultural Sciences on how to keep the pests out of your home.
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Palmetto bugs, or American cockroaches, are known to invade coastal South Carolina homes. Here are some quick tips from the University of Florida's Institute of Food and Agricultural Sciences on how to keep the pests out of your home.

Do you think winter is rough on you? Be glad you’re not an adult palmetto bug.

“When winter comes around many of the adult palmetto bugs die,” said Eric Benson, professor of urban and medical entomology at Clemson.

For their younger and unhatched counterparts, winter is a time to find shelter wherever possible, be that in mulch, holes in trees, in leaf piles or maybe even your home.

“If a Palmetto bug, which is basically just a cockroach, if they’re against a structure and they have a choice between being out in the mulch or finding that crack or crevice that lets them wriggle into the structure, they’ll often go into the structure,” said Benson.

Many times, getting into a home isn’t a case of finding a hole or a crack in a wall, but coming in through the roof. Palmetto bugs will climb trees, Benson said, using branches that touch the tops of homes as bridges. Then it is just a matter of finding an entry point.

1. When do they move in?

Palmetto bugs are a part of life in the Lowcountry year round, but they find extra motivation to move into homes and structures as temperatures drop. Benson said that once it is consistently below 55 degrees, their shelter seeking instincts kick in.

When they move in, though, you might not notice them.

“You can see some activity in Palmetto bugs that get into your home, but they’ll basically have the same seasonal lethargy as their outdoor counterparts,” said Benson. “The most calls I get on Palmetto bugs are when it starts to cool down and they start moving in to structures, and in the springtime when it starts to warm back up and they become more active and people start to see them. I get fewer calls in the dead of winter or the dead of summer.”

Even though they aren’t active, Benson said, they aren’t hibernating.

2. What are they looking for?

Palmetto bugs tend to spend the winters hunkered down, waiting for the cold to pass, and spend summers outside, where warmer, more humid conditions are preferable those inside most homes. According to Benson, moisture is a big deal for them.

“Anywhere where there is moisture, they can use it to survive,” said Benson. “They like to drink water but they also like to be in relatively moist sheltered environments.”

This means that in addition to damp crawlspaces or attics where leaky roofs might provide what they are looking for, palmetto bugs can reliably be found in gutters where water has collected and around poorly caulked windows, Benson said.

3. Why do the adults die?

“As the winter progresses and you get more cold days down around freezing, that can cause some mortality,” Benson said. “But to a certain extent the adults are going to die anyway. They’ve basically lived out their life time, so its not so much that the winter is killing them. It is basically that they’ve reached old age for a bug.”

Even palmetto bugs raised in laboratory conditions, where temperatures are kept consistent year round, tend to die during winter, Benson said. This fact could have to do with their breeding patterns, which are seasonally influenced.

The average life expectancy for a palmetto bug is two years according to Benson. That life normally starts off in the spring. The bug will then develop into adulthood by the end of the ensuing winter and breed the following spring, reaching “old age for a bug,” as Benson put it, as winter comes around again.

“If you have palmetto bugs in a very suitable, good environment their lifespan can be shortened because their rate of development will increase,” said Benson. “We rear these things in colonies and we can have them go from egg to adult in far less than a year.”

That means that in ideal conditions, without having to compete with wintry conditions, a Palmetto bug will burn through its entire life cycle in about half the time of its counterparts out in the world.

Not all adults die in the winter, though, Benson said.

4. How do I know if I have a problem?

With palmetto bugs tending to keep to themselves during the winter months, it can be difficult to tell if you have an infestation waiting for you.

In fact, you might have to wait until spring to see if you have a problem, Benson said. There is no reason to panic if you see a large palmetto bug or two.

If you see small ones, though? That is a different story.

“If you were to see tiny little baby ones, they’re usually chestnut brown to blackish, if you saw a bunch of little ones, that could indicate that an egg case was deposited and successfully hatched,” said Benson. “If you have that, that is probably a location where they have food, water and shelter.”

5. How do I prevent/get rid of them?

Palmetto bugs thrive on food and moisture, like most living things. The easiest way to stop an infestation before there is one, according to Benson, is to deprive them of that.

“You should probably make changes, like caulking leaks in windows or fixing leaky gutters,” he said.

He recommends making sure your home is in good repair and that there are no easy access points for them. You should also trim back any tree branches or bushes touching your home and reduce excessive mulch.

If they do get in, Benson suggests using roach baits. You can also use roach sprays or boric acid powder, which are widely available. Simply spray or sprinkle them in cracks and crevices where palmetto bugs like to hide.

Michael Olinger: 843-706-8107, @mikejolinger