By Mike Isbell
University of Georgia

The rear end of a white grub isn’t a pretty sight. But if you’re
going to identify the grubs that are damaging your lawn,
somebody’s got to look.

That somebody is going to have to use a magnifying glass, too,
which makes the grub’s rear end look even bigger.

Lately, I’ve had a lot of calls about crows and even wild turkeys
digging up turf grass looking for stuff to eat. In a lot of these
cases, the birds are digging for grubs in the soil.

Moles, skunks, raccoons and armadillos, as well as birds, all can
root up the turf hunting for grubs. And even if animals aren’t
digging, the grubs themselves can damage turf grasses.

Damage symptoms

Most grubs feed on grass roots, cutting the plants off from water
and nutrients. Damage from grubs appears as yellowing or browning
of the leaves, signs of drought stress even when there’s
moisture, and loose turf that pulls easily from the soil.

A typical phone caller will say something like, “Mike, I was out
mowing my lawn and my mower just tore up the grass by the roots.”

Sounds like grub damage to me.

Grubs feed most actively and are easiest to control during late
summer and early fall. But they may be active in warm periods
throughout the winter.

Main culprits

More than a dozen species may damage turf in the Southeast, but
the main ones we have are green June beetles, chafers, Japanese
beetles and May beetles or June beetles.

While white grubs in general are among the hardest turf pests to
control, the green June beetle grub is one of the easiest.
Because they come to the surface at night, green June beetle
grubs come in contact with insecticides more readily than the
other grubs that remain deeper in the ground.

To check for white grubs, cut three sides of a square foot of
turf with a shovel. Then fold the sod flap back and look for
grubs in the top 2 or 3 inches of soil and roots.

Some species can damage turf with just four grubs per square
foot. Others can have 10 to 20 per square foot and still not
damage turf.

Which grubs?

If you find white grubs in your soil, how do you know which one
it is? Well, if it crawls on its back, with its legs sticking up
in the air, it’s a green June beetle. I’m not making this up –
they do crawl on their backs.

If they don’t crawl on their backs, that’s when you use your
magnifying glass. But you have to be willing to get close, and
you have to know what you’re looking for. It’s not for the
squeamish.

With an identification key available from the Extension Service,
you can identify the grubs you find. If you can identify them,
your county agent can tell you what to use to control them.

You don’t have to be an entomologist to identify a grub. But a
proctologist? Maybe.

(Mike Isbell is the Heard County Extension Coordinator with
the University of Georgia College of Agricultural and
Environmental Sciences.)