Drought Could Slow Japanese Beetle Spread

Jan 30, 2013

Local plants might find a silver lining with the recent drought.

The Japanese beetle, an invasive species with no natural predators and no simple way to kill off, can be affected by the recent dry weather. This could be a boon for gardeners who otherwise have no good way to fight off this growing pest. Without a natural predator, a species like this will continue to grow and thrive.

Missouri Department of Conservation’s Forest Entomologist Rob Lawrence says the dry weather affects their larval stages the most.

“They do not do very well when  we have a lot of drought, a lot of really dry soil,” Lawrence said. “So if in your neighborhood nobody was really watering their lawns, back during all that drought, that might actually help reduce the Japanese beetle population a little bit.”

Lawrence says they do damage to lawns in larval stages, but really get to business as adults.

“When they come out as adults, the adults fly around and they feed on a wide range of plants, and they feed on the leaves and they’ll feed on flowers and fruit and so forth, but feeding on a wide variety of plants,” Lawrence said.

He cautions people on using  traps, due to their failure to trap all of the beetles while still attracting them. Biological controls have failed to have a large impact as well. But here’s the good news: The ongoing drought could slow down the invasive pest’s spread.

Lawrence says if you attempted to keep your lawn nice and green, it might have actually benefited the beetle, causing their population to grow. So before you decide whether or not to water your lawn, pause and consider the larger implications.