Identifying Mole Crickets
Mole crickets are strange-looking pests, with bodies like crickets and clawed front legs designed for digging through soil, similar in shape to a moles’ front paws. This combination gives mole crickets an appearance that’s a cross between a cricket and a crustacean.
Mole crickets are fine-haired and velvety, with three segmented body parts and three sets of legs, plus two antennae. Fully grown adults range in size from 1-2 inches long, while the nymphs, the immature stages, have the same body type at a smaller scale, and no wings.
The two most common types of mole crickets are the tawny mole cricket and the southern mole cricket. Tawny mole crickets are tan and larger comparatively, nearly two inches long as adults. Southern moles crickets are dark brown and are about 1 ½ inches long when mature.
Unlike your common cricket, mole crickets are not good at jumping. But they do chirp.
Signs of Mole Cricket Damage
Mole crickets are most likely to damage bermuda grass and bahia grass. The telltale signs of mole crickets are disturbed soil, irregular tunnels, and dying grass. As mole crickets tunnel, they leave runways like moles do, as well as uprooted seedlings. As they burrow, mole crickets push up the soil, damaging grassroots and leading to dead patches.
Tawny mole crickets are more destructive to lawns than southern mole crickets. While both species plow through the soil, tawny mole crickets actually feed on grassroots and grass shoots. On the other hand, southern mole crickets feed on the organisms in the soil, not the actual grass. This will cause your grass to feel spongy when you walk on it, since the turf has detached from the soil.
As they mature and these warm-season grasses slow down from their most active growth period, mole crickets do the greatest amount of damage. This is usually from late August to October, but conditions like moisture levels and soil temperature may change this, as they impact feeding and tunneling habits.
When temperatures drop and winter begins, mole crickets begin to “overwinter” deep in the soil. This translates to less damage.
Mole Cricket Life Cycles
One generation of mole crickets typically occurs once per year, or twice, the further south you go. Each generation has three stages in the life cycle—egg, nymph or “immature,” and adult. Both nymphs and adults can overwinter. As the temperatures warm up, the nymphs will turn into adults, and the adults will seek out females to mate.
The males will die shortly after mating, and the females will lay a cluster of 2—40 eggs in an underground chamber. Females will lay about 100 to 150 eggs before dying. How long it takes the eggs to hatch will depend on the soil temperature, with eggs hatching earlier in the warmth. In general, it takes about three weeks.
That means that by late spring or early summer, the nymphs will have grown large and hungry enough to start extensive damage. However, because the warm-season grass is actively growing at this time, the damage can remain hidden until the weather cools down—and it may be too late.
Mole Cricket Monitoring and Control
This means that the nymphs must be dealt with before you may even know they’re there. You’ll have to pay careful attention to your lawn for signs of adult activity. Ideally, you would try to eliminate adults in the spring before they can tunnel too much and lay eggs. Then, you would eradicate any destructive nymphs that survived.
The most vulnerable time for nymph mole crickets is when they’re newly hatched, in late spring and early summer. At this point, they’ll be about ¼ of an inch long and won’t have burrowed too deeply into the soil—making it much easier to eliminate them than when they’ve doubled in size and dug deeper a few weeks later.
Flushing Mole Crickets Out
There’s an effective test you can try if you think you’ve detected mole cricket activity. Mole crickets will burrow deep into dry soil but will emerge in most soil. You can flush them out with a combination of dish soap and water.
Mix two tablespoons of liquid dishwashing detergent, like Dawn, with two gallons of water. Pour it over a 2-square-foot area of your lawn. The mole crickets should pop out of the soil as the soap mixture sinks down. One or two is not a big deal. But if you see two to four within a few minutes, you need to take action. Mole crickets tend to infest the same area of grass every year, so it’s a good idea to map out the area where the mole crickets came out.
When to Treat Mole Crickets
After you’ve mapped out the affected area of your lawn, monitor it through the seasons. Examine it for signs of loose soil and poor growth in the winter, and for tunneling in the spring. There is no real reason to treat adults with chemicals then, because after the eggs are laid, the adults will die.
Instead, wait until June and July—the eggs will have hatched, and the nymphs will be small and vulnerable. You can also apply additional chemical control, as needed, later in the summer.
Pesticides will be most effective in warm, moist soil—if the soil is dry, the mole crickets will burrow down deeper and be harder to target.
Ultimately, it is difficult to fully eradicate mole crickets because their development depends on soil and weather conditions. Because of this, your best bet might be to hire a professional lawn care company that protects lawns from mole crickets.
Mole Cricket Control Options
You can try either chemical or non-chemical approaches to mole cricket removal. The best methods depend on the stage of the life cycle. Summer treatment is effective on nymphs, while spring treatment is more effective against adults.
As of now, the most effective natural method for killing mole crickets is introducing beneficial nematodes into your soil. These naturally occurring parasites infect the pests with bacteria, which then eat the cricket from the inside. This measure is more effective at killing adults than nymphs and may take a long time to show results. The best time to apply beneficial nematodes is either in early spring or fall.
Some people say that there are natural deterrents you can plant, including marigold and chrysanthemums, to ward off mole crickets in the first place.
The two primary ways of killing mole crickets chemically are using mole cricket baits or insecticides.
You can find mole cricket baits at garden centers or online. Baits containing grains and toxins have been shown to be effective. Place the baits in the early evening, since mole crickets feed at night. Be mindful of the weather forecast because rainfall can wash away your bait or render it ineffective. Do not water your lawn for at least two days after setting mole cricket bait. Baits do well against adults in the spring and fall.
Insecticides come in granular and liquid form. They fall into three major categories: synthetic pyrethroids, neonicotinoids, and organophosphates. You might want to consider alternating the category type or use a product that contains two categories, since mole crickets can develop a resistance to specific types over time. Read the instructions carefully. Typically, you will need to water the lawn after applying one of these insecticides. These are normally applied in early summer to kill small nymphs.
Applying insecticides can be hazardous. It might be best to leave this in the hands of a professional, especially since they require routine reapplication.