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Mole Crickets
By David W. Held, Ph.D., Dept. of Entomology and Plant Pathology, Auburn University; Yao Xu, Doctoral Student, Dept. of Entomology and Nematology, University of Florida; and David Bailey, Graduate Student, Dept. of Entomology and Plant Pathology, Auburn University
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awny and southern mole crickets are the most significant insect pests of warm-season turfgrass. The underground habits of these pests can make their biology difficult to study. This report highlights recent work supported by the ATRF that provides insights on the biology and management of mole crickets.
Al ab am a Tu rf Tim es >>> S umm er 20 13
Underground behavior In 2012, while completing his Master’s degree, David Bailey studied the tunneling behaviors of mole crickets and their impact on water movement through soil. Mole crickets make tunnels through soil that are about two-and-a-half to three times their body width, compared to earthworms that make tunnels equal to their body width. And adult mole crickets logically make wider tunnels than nymphs.
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Tunnel architecture is greatly influenced by soil type. David compared the tunnels of southern mole crickets in sandy, loam and clay soils and found that mole crickets tunnel more extensively through loam soils. In one week, tunnels in loamy soils have an average linear length of about 25", which is more than twice the length of tunnels in clay. Under laboratory conditions, one adult southern mole cricket displaces about 14 tablespoons of loamy soil in one week. Bermudagrass fairways on a golf course were used to determine the effect of mole cricket tunneling on water infiltration or runoff. Fairways with severe mole cricket infestations and those with no visible mole cricket activity were compared using a Cornell Sprinkle Infiltrometer. As expected, runoff was greater and infiltration less in plots that were not infested
with mole crickets. Turfgrass with extensive damage by mole crickets will have high groundwater infiltration, enabling solutes (i.e., fertilizers and pesticides) to move from the surface into the soil faster than through an intact soil profile. We don’t fully know the implications of these data. For one, damaged turfgrass is more porous, and this may facilitate penetration of surface-applied insecticides into the soil and enhance their efficacy. However, this may also hasten the movement of pesticides and fertilizers to groundwater. This would be most relevant in spring and late fall when large mole crickets are causing extensive damage at the same time that insecticides are applied to clean up those areas. The most common pesticide application window is just after eggs have hatched, when small nymphs are