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  • Writer's pictureChelle Hartzer

You Don’t Know Karst (AKA: Bring out your dead!)

It’s almost October so I’m perfectly okay with starting the Halloween series. Because it is the best holiday of the year. I was doing a wine-ing video on cemeteries and pest control which inevitably led to a literature search, 30 open tabs, and at least 20 scientific papers. While you will have to wait for the next wine-ing, the extras are going in this week’s blog. You’re welcome!

What do cemeteries have to do with karst? Great question, thanks for asking.


I had to look up what the word “karstmeant the first time I saw it. Karst is “a specific type of terrain formed by the dissolution of carbonate rocks and is characterized by the presence of sinkholes, caves, springs, and streams.” Urban karst is a little less defined but is basically basements, undergrounds, sewers, and other man-made “caves”. Because these are below ground and range from damp to holding water, they are a perfect spot for many pest insects.


Back to cemeteries. There are so many areas of a cemetery that are karsts. There are old graves that may have collapsed down and filled with water. Mausoleums can hold water in different areas. Crypts are much the same.

But what is the connection to pest control? So glad you asked. It’s not a big leap to connect carrion (aka dead bodies) to flies, beetles, and other decomposers. We aren’t necessarily talking about that, we are talking about water building up in underground “caves”. There are lots of urban pests that need water and wet conditions. When we think about those standing water sources, mosquitoes are one of the biggest pests. Since those populations are protected or at least partially protected underground, there are fewer predators and the mosquito populations can explode. It’s not just the visitors to the cemetery, it's all the surrounding homes and businesses that are going to see an influx of little vampires.


Midges can also use these water sources. Luckily midges are more of a nuisance but that’s not going to stop customers from calling

On top of the karsts, there are all the other water sources. One of the big ones is urns and vases for flowers. As the flowers sit and decompose in the water, they create decomposing organic material for all kinds of small flies like phorid flies (which also feed on carrion), moth flies, and fungus gnats.


Some old cemeteries are not as well maintained as newer ones and that can cause additional standing pools of water. The extra vegetation can also encourage wildlife like mice and rats. Those mice and rats will be foraging at nearby structures for food and creating issues. Then there are the ticks, fleas, and mites that the rodents carry.

For cemeteries that are well manicured, there are often lots of flowering plants and trees that are well watered. During periods of drought, all types of pests are going to be drawn to that area for water and the plants that can feed them. Then they migrate to other landscaped areas like homes and businesses.


There are so many pest issues that can start in cemeteries and then affect the surrounding above ground population. This is why it is important to investigate what is around a particular account. Cemeteries seem nice and harmless, the neighbors are pretty quiet! That doesn’t mean they can’t cause problems for surrounding areas.


I didn't even mention cockroaches!

If you need help with a scary pest problem and narrowing down spooky sources, we can do that for you! Contact us now for a free assessment.


Lagniappe - watch to the end!



Urban pest consulting.

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