Causes for holes in yard

Q. I have lots of holes in my yard. They are small mounds of excavated dirt with an emergence hole. They started near the end of November. Is this an insect?

Janet

A. This was an interesting question, with several possibilities for the answer. Based on the description, this is not a hole, or a mound made from a mole or vole in the landscape.

Thus, further information was sought from our nursery, landscape and turf team at Ohio State University. One of our experts, Dave Shetlar, suspects these mounds were made by some of the semi-aquatic crayfish, but that they also could be the soon-to-emerge periodical cicadas (set to emerge in the eastern third of Mahoning County later this year). Dave has been receiving reports of early cicada emergence for the past year, as some of these insects forget they are all supposed to be on the same 17-year cycle.

But based on the photo of the rather large hole (about a half-inch across) and mound of mud, it could have been crayfish as well. Dave says that you don’t really have to be near a pond to have the crayfish, just in an area where the water table is high. They are seen commonly along roadside ditches where the water table is sufficiently high enough to allow easy access to the ground water.

Another entomologist suspects a third possibility is that they are night-crawler earthworm holes and mounds. The warm weather through December kept them active and close to the surface of the ground. The accumulation of worm castings and leaf litter that they pull into their holes to consume make the mounds. The rain would smooth the mounds. But it would be a rather large night crawler to make a hole as large as the holes in the photos provided.

In any case, there should be no attempt to control the critters by pouring insecticide or other toxins in the holes as the burrows likely connect to the ground water system. Plus, night crawlers help recycle nutrients in our lawns, keeping the lawn healthy.

At many of our programs regarding insects, we talk about being in the right place at the right time to find out the insect or animal causing issues in our landscapes. Sometimes, this involves using a headlamp on the red light setting either later in the evening or very early in the morning to see if you can spy the culprit.

For more information on the periodical cicadas, view our updated factsheet about their emergence here in the Mahoning Valley this year at http://go.osu.edu/cicadas.

To learn more about crayfish visit http://go.osu.edu/crayfish.

To learn more about night crawlers visit http://go.osu.edu/nightcrawlers.

Eric Barrett is OSU Extension educator for agriculture and natural resources in Mahoning County. Call the office hotline at 330-533-5538 to submit your questions. Regular clinic hours are over for the growing season, but you can still call and submit questions. Hours vary throughout the winter season.