Unsightly Mounds in the Lawn

For the average home lawn, armyworms are not something you need to be concerned about. From calls to the county extension office the typical report is multiple mounds two to four inches in diameter, sometimes with a hole in the center but sometimes without. The most common cause this time of year is the cicada killing wasp. Read More...

Unsightly Mounds in the Lawn

Home Grown  by Keith Reed
It’s about the time of year to begin seeing small mounds of soil appearing in your lawn. The typical report is multiple mounds two to four inches in diameter, sometimes with a hole in the center but sometimes without.

There are a couple of insects that can create this type of soil structure but the most common cause in September is the cicada killer. This very large wasp (about an inch and a half long), while quite intimidating at first glance, is usually benign and harmless. Even though the female cicada killer can sting people, it generally only does so when provoked. The male of this species is more aggressive but it lacks the capacity to sting.

As the name indicates, cicada killers do kill and feed on cicadas. The mounds are created from the soil removed to create a burrow the insect uses as a home to lay its eggs. The dead cicada is placed in the burrow to provide a food source for the newly hatching wasp larvae.

Under most circumstances, control of these insects is not suggested since they are rarely a problem for humans and cause no disruption to our food supply. If unusual circumstances necessitate control, there are some options. Any “knock down” wasp control product will work. Individual mounds can also be treated with dusts labeled for wasp control. As with any pesticide, read the label and follow directions carefully.

Another insect we generally get calls on this time of year is the cricket. Crickets are generally just a nuisance so control measures are not suggested. The best a homeowner can do is to keep outdoor lighting to a minimum around building entries. It may also help to keep dead crickets swept up as it is thought that the swarm tends to build on itself as the crickets search for mating partners near the end of their life cycle.

For more information on this or any other horticultural topic, you can contact Keith Reed, the Horticulturist in the Payne County Extension office. Keith can be reached via email at, phone at 405-747-8320, or in person at the Payne County Extension office, located at 315 W. 6th in Stillwater.

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