July 11, 2000
Let's Talk Grub Control 

         I hope that by the time you’re reading this that the weather has warmed up a bit.  Temperatures are lingering in the low to mid seventies; just about ten degrees cooler than normal.  I rather enjoy these temperatures but they’ll make an already late season slow down.  I expect that, out in the Glenville hills, I’ll be harvesting what few tomatoes I’ll get sometime in late August or early September.  I guess I shouldn’t be complaining.  At least it’s not raining. 

                Even though I haven’t seen any at my place, I’m hearing that the Japanese Beetles are starting to emerge from the soil to begin their feasting.  In an artist’s eye, the Japanese Beetle could be considered an attractive specimen with its shiny, coppery-bronze wing covers and metallic-green highlights.  Unfortunately, this color scheme isn’t attractive to birds or any other insect predators so, we’re left to battle these destructive, leaf eating beetles on our own.  There are few things that can send gardeners into a state of insecticidal rage quicker that the sight of a group of Japanese Beetles chowing down the petals of a favorite rose bush or crop of beans. 

                Our first line of defense is Japanese Beetle traps.  These yellow traps with their floral and sex lures are almost irritable to hungry, sex-crazed Japanese Beetles.  The trick to using beetle traps is to not place them IN your garden but 15’ outside the garden.  You don’t want to lure the beetles into the garden after all.  If you home is somewhat isolated, traps can be quite effective.  In the suburbs, with many lawns adjoining and surrounding yours, the use of traps can actually increase the number of beetles in your gardens.  In this situation, spraying may be the only solution.  In the past, Sevin was the insecticide of choice.  Recently, however a product called “Eight” has come on the market and looks as though it will do as good a job as Sevin but with a lower toxicity (making it safer to use).  As with Sevin, Eight is available in dust or liquid sprays.  While Sevin required that the insects eat it, Eight kills on contact and remains effective for a couple of weeks after (or until rain washes it off the leaves).  Try to avoid using Sevin or Eight dusts on plants with lots of flowers since bees visiting these flowers may carry the dust back to the hive with their pollen deliveries and harm the hive.  In those situations, a spray of liquid Methoxychlor will be safer for the bee population.

                In the past we all knew to treat for grubs “in the fall”.  Recent developments in insecticidal chemistry have changed all that.  Now we want to treat for grubs as soon as we see Japanese Beetles in our area.  I wrote about all this in an earlier column but, I imagine most of you need another reminder so I’ll quote myself:

                “ What’s the best thing to use?  In my opinion it will be one of two products.  Either the chemical Imidacloprid (sold as Merit Season Long Grub Control) or the biological control (non-chemical) Milky Spore Disease.

                Let’s start with Merit: Ideally, you’ll want to apply Merit in mid to late July and WATER IT IN.

By now you must think I’m totally nuts.  I just explained how there aren’t any grubs in July because they are all in the beetle form eating the beans and roses.  Rest assured, I’m not nuts.  The reason Merit needs to be applied so early is that it needs some lead time to get absorbed into the roots of the grass where it remains waiting for the grubs.  As soon as the grubs hatch they begin to eat the roots of the grass.  POW!  They die.  That’s the beauty of Merit.  It can’t miss since it’s in the food of the grubs.  Properly applied and watered-in Merit will kill 98% of the grubs that hatch.  No need to lose your lawn…no need to treat again in spring either.  Don’t worry, your neighbors grubs will stay in his yard.  Grubs aren’t much for traveling.

                Better yet there’s Milky Spore Disease.  Milky Spore is a disease that only affects white grubs.  It won’t hurt earthworms or even a bird that eats a grub that has the disease.  Milky spore needs to be applied

two or three times a year for three years to reach “epidemic” proportions in the soil.  After that the grubs that hatch into your lawn will contract the disease then die reproducing the disease and spreading it throughout the soil.  Milky Spore is more expensive up front but will last at least 20 years once it takes hold.  Not a bad investment really.  Over the years it will actually save you money to say nothing about the time you won’t need to spend spreading chemicals and running sprinklers.” 

                Remember that?  Another reminder: Don’t count on rain to properly water-in your grub control.  A soon as the product is out of the bag, oxygen and sunlight will break down Merit in a matter of hours and Milky Spore is killed if left exposed to sunlight for too long.  Put a tuna or cat food can on the treated area and don’t shut the sprinklers off until the can is full.  THAT’S how much water it takes to allow these grubs controls to be effective!  Make this the year you GET WITH THE PROGRAM.  Our lawns have made a great recovery from last year’s drought.  Down let those grubs get the jump on you and destroy the healthy roots system this spring’s rain made possible  Thanks for the read.