GARDEN DETECTIVE: Getting rid of - ewww - grubs

I was digging in my garden yesterday and found these (photo enclosed). I think they are grubs. If they are, what should I put down to get rid of them? When is the best time to apply? Thanks.

Joe Koloski, Hicksville

You're right - those half-inch to inch-long off-white things are grubs. Ewww.

Grubs actually are the larval stage of Japanese, Oriental or European chafer beetles, and until they fully morph into adults, they survive by eating grass roots under the soil level. Good for the grub, not good for your lawn.

The bigger grubs get, the more roots they consume. The most damage occurs during spring and fall, because beetles lay eggs in late summer and newly hatched grubs embark on a feeding frenzy before hibernating for the winter. They wake up, so to speak, in early spring and begin feeding again before becoming adult beetles and laying their own eggs to start the cycle all over again.

If your lawn develops dead patches, pull up a section just outside the affected area and check the soil underneath. The presence of groups of eight or more grubs per square foot is cause for action; smaller populations shouldn't present a problem.

Lawns that are badly infested can be lifted easily and rolled up like sod because the grass becomes completely severed from its roots. Naturally, without attached roots, the grass dies.

Early August is prime time to inspect for grubs. It's also the best time to treat against them because they're at their weakest right after hatching. Although you might just be noticing last fall's lawn damage now, springtime treatments can be a waste of time and money, not only because of diminished effectiveness, but also because there will be another generation of grubs right around the corner when beetles lay more eggs.

Heterorhabditis bacteriophora, a species of beneficial nematodes, are a nonchemical means of targeting young grubs. Allowing grass to grow taller and cutting back on irrigation may discourage beetles from laying eggs in the area, consequently reducing the grub population.

Milky spore, a disease that sickens and kills grubs, is widely sold in powder form as a remedy, but it only works against Japanese beetle grubs, so if you're dealing with one of the other species - and you likely have no way of knowing this - it would be useless. Plus, it can take several years for milky spore treatments to take effect. Chemical pesticides also may be used, but many are not available for sale to homeowners in New York State, so you would have to call a certified pesticide applicator.

If you go the pesticide route, check with the Cornell Cooperative Extension for specific recommendations: 631-727-4126 in Suffolk 9 to noon Monday through Friday, 516-228-0426 in Nassau 10 a.m. to 12:30 p.m. Monday through Thursday.