Rowan, left, and Colt Stensberg volunteer at Father Marquette Catholic Academy, including helping with gardening work. (FMCA photo)

By IRIS KATERS

Special to the Journal

MARQUETTE — STEM classes can get mighty grubby sometimes as Father Marquette Catholic Academy’s Alex Gencheff’s science students have discovered.

While digging up lawn for four more raised vegetable and herb beds they discovered an infestation of Japanese beetles. The project is supported by the MSU Extension nutrition education program.

Like other Upper Peninsula residents, students are digging up a relatively new kind of grub that has been eating their lawns all winter and is now going to emerge soon to eat anything with a petal or berry. The attached females and males will soon be found together voraciously munching on their favorites–roses, peonies, raspberries. They are not fussy, though. They will eat almost anything.

Rowan and Colt Stensberg, regular after-school student volunteers, added to the count of 103 curled C-shaped grubs that fifth-grade students found earlier during STEM — science, engineering, technology and mathematics — class in a 10- by 20-foot area.

“There are too many! These are nasty to pick up,” Colt said as he flung another grub on the ground and joyfully stomped on it.

“We are digging them up, so they don’t emerge and damage our gardens as adult Japanese beetles,” his sister Rowan explained.

Now found in most states including local lawns and gardens, they are doing major damage to homeowners’ lawns, landscaping, garden crops and commercial orchards. Often lawns are gone before owners realize there is something seriously wrong.

What may start looking like winter damage turns to bare spots and then the ravens, crows and other flocks of birds may move in and decimate the lawn overnight. Skunks, moles and birds can’t keep up. Local neighborhoods have bare ground instead of a lawn due to Japanese beetle grub damage.

FMCA students urge residents to research treatments online. There are no cures, but several control methods will help avoid an expensive disaster in local yards.

Microscopic beneficial nematodes are being used in 30 states. They attack the grubs and eat them, but are harmless, relatively inexpensive, naturally found in the ground in low numbers and must be applied now before the emerald green beetle emerges.

They are applied again in fall to kill the eggs hatching into grubs that merrily eat lawns again all winter. Park Cemetery volunteers in Marquette have found the beneficial nematodes effective and easy to apply to save flowers and shrubs.

There are also heavy-duty special chemical treatments that are different from the usual grub control. They may be harmful to children and pets.

Once the beetles emerge and attack fruit trees, shrubs, flowers and gardens, homeowners have few options other than netting or picking them off and placing them in soapy water. They seem to be immune to normal sprays that will, unfortunately, kill honeybees and other beneficial insects.

Simply shaking them off or using a water hose to knock them off to the ground will help them lay their eggs. Each beetle is protected by a hard shell and will simply lay hundreds of eggs for next year to continue their cycle.