Johnson's Garden Centers Text File document - copyright 2007 
PDF file available at http://www.johnsonsgarden.com/advice.html#lawnpests

Don"t Let Grubworms Get the Best of Your Lawn 

    The evidence of damage by grubs (whitish, c-shaped worms found in
the soil) appears in August and September. Spots or patches of damaged
turf may wilt, turn brown and die-even though the turf is getting plenty
of water.

    The grass root zone should always be inspected for grubs if dead
areas appear in August or September. Test your turf by grabbing a
section and pulling up. If it comes up like a carpet, grubworms have
been feasting on your lawn. You won"t need to look too deeply in the
soil to find the offending grubs.

    In Kansas, we have two different types of grubworms. The Southern
Masked Chafer has a one-year life cycle and tends to be the most
destructive of the two, due to the great number of these insects. The
other grub is the May Beetle (also know as June Bug). It has a
three-year life cycle with the second year being the most destructive.

    Although lawns can withstand a small population of grubs, three or
more per square foot of turf is enough to justify treatment. Application
timing is important and varies depending on the product used. Hi-Yield
Grub Free Zone, containing Merit may be applied as a preventative
earlier in the year than traditional grub products. It is the only grub
control that is effective when applied in late spring to early summer.
After treatment, water deeply to get the product down into the soil. The
effectiveness may be affected by excess moisture. If we have a wet
summer, keep an eye out for grub damage and follow up with one of the
insecticides listed below.

    Hi-Yield Kill-A-Grub, containing Mach disrupts the grubs" life
cycle, causing the insects to stop feeding. One application in their
early development, mid June to early August, will prevent damage by
grubs all season long. It is not important to water in Kill-A-Grub
granules the way you need to with other grub control treatments.

    To treat grubworms after you start to see damage in August through
September, use fast-acting Bayer 24-Hour Grub Control with Dylox. The
Southern Masked Chafer grubs are still very tiny and are feeding in the
upper 2" of soil surface. The critical treatment time is 3-4 weeks
after the egg laying. After treatment, water deeply to get the product
down into the soil.