Mole crickets are burrowing insects that pose a threat to turfgrass, particularly in warm, sandy-soil environments found across the southeastern United States. These pests spend the majority of their lives beneath the soil surface, creating damage through physical tunneling and feeding habits. Identifying the specific visual evidence of a mole cricket infestation is the first step toward effective management. Since the signs often mimic damage caused by other pests or environmental factors, a detailed understanding of their activity is crucial for accurate diagnosis.
Visual Signs of Subsurface Activity
The most immediate evidence of mole cricket activity is the physical disruption of the soil surface. As the insects tunnel just beneath the grass line, they push up the soil, creating characteristic meandering tracks or ridges. These elevated trails resemble tiny fissures or miniature mole tunnels, and they are especially noticeable after watering or rainfall when the crickets are most active near the surface.
The crickets’ burrowing also produces distinct soil disturbances that appear as small, conical mounds of loose dirt. These formations are created when the insects push soil out of their burrows, sometimes resembling an ant hill but composed of coarser material. These mounds are often seen around burrow entrances and confirm active excavation beneath the turf.
A single cricket is capable of damaging several square feet of turf in a night. This constant movement near the surface dislodges new seedlings and uproots grass roots. This physical disturbance is the primary source of initial damage, weakening the turf even before feeding activity becomes extensive.
Appearance of Grass and Root Damage
The physical damage from tunneling quickly translates into a visible decline in grass health. The most common symptom is the appearance of irregular patches of brown, wilted, or dead grass that do not respond to watering. These patches frequently appear in late summer or early fall when the nymphs are large enough to cause significant destruction.
Areas of heavy mole cricket activity often feel soft and spongy underfoot. This sensation is caused by the grass roots being completely severed from the underlying soil by the burrowing insects. The tunnel network detaches the turf layer from the ground, leading to poor water and nutrient absorption.
In severe cases, the damaged grass can be easily lifted or rolled back like a loose carpet because the root system has been destroyed. While some species feed directly on roots and shoots, all species cause damage by pushing through the root zone while digging tunnels. This combination of physical uprooting and feeding leads to the thinning and eventual death of the turf.
Confirming the Presence of Mole Crickets
Since mole cricket damage can be mistaken for symptoms of drought, disease, or other pests like grubs, a diagnostic method is necessary to confirm their presence. The most reliable technique is the soap flush test, which temporarily irritates the insects and forces them to the surface. This test should be performed in areas showing the earliest signs of damage, such as where light tunneling ridges are visible.
To conduct the test, mix two tablespoons of liquid dishwashing detergent into one gallon of water. This mixture is then poured evenly over a small, suspected area, typically about four square feet of turf. The detergent acts as an irritant that causes any mole crickets present to emerge from their tunnels within a few minutes.
If two to four crickets emerge from the treated area within three minutes, it confirms a population density high enough to warrant control measures. Adult mole crickets are distinctive, measuring about one to one and a half inches long with a velvety, brown or tan body. Their most identifiable feature is their large, shovel-like forelegs, which are adapted for digging through the soil.
Nymphs, or young crickets, appear as smaller versions of the adults. Their presence in the flush test is important for confirming an active infestation.