Milky Spore

Ah, August.  The season of sharpened pencils, shiny shoes, and first-day jitters.  And the harbinger of the collective germ pool shared amongst all those willing learners.  From the water fountain to the pencil sharpener, bacteria has a hey day.  With three grade-schoolers, I’m in the thick of germ warfare.  A daily lecture circuit escapes semi-unconsciously from my mouth:  “Wash your hands.” “Use a tissue!” “Stop licking your brother.”  Does it do any good?  Do they listen?  I don’t know.  We get our fair share of stomach viruses and strep throat.  I always say what we don’t pick up from the community basketball in P.E. we get from the shopping cart at Aldi’s. 

But thank goodness I’m not a grub mama.  As those little baby grubs wriggle off from home into the pitch-black underworld, they’re exposed to every imaginable germ.  How they can see what they’re eating?  Who knows?  And there’s clearly no hand-washing before meals.  One soil-borne germ in particular, milky spore, is deadly to grubs.  Oh, those poor mamas, the sleepless nights they must endure with such dangers lurking.  You may be more familiar with the parents of grubs these days: our iridescent summer visitor, the Japanese Beetle.  What?  Not feeling sympathetic?  I can relate. 

A creepy Grub family tree

I suppose beetles can’t help their behavior.  They’re just doing what comes naturally.  It isn’t their fault that we’ve planted all these delicious Linden trees and hollyhocks, roses and beans around our properties.  After all, if the tables were turned, would we behave differently?  If Willy Wonka’s dream came true, would we leave the candy grass, gumdrop flowers and chocolate river alone simply because they looked lovely?  One whiff of that cocoa current and my self-restraint would be taking a hike.  This, however, isn’t Wonka World, and I’m not here to make excuses for Japanese Beetles.  We have crops to grow and plants to protect from the appetite of these destructive creatures, which brings me back to the milky spore germ.

It’s important to clarify what Milky Spore (Bacillus popillae) is not.  It is not a quick fix.  Yes, I know you’re worried about the marigolds the beetles are currently feasting on, but Milky Spore is not that kind of a fix.  It does not instantly kill beetle like Sevin.  This is a gradual population-control product.  I know I lost most of you on the word “gradual”, but hear me out.  This bacteria attacks the future generations that will be overwintering in and emerging from your soil next spring.  It’s like taking out an airfield instead of just shooting bombers out of the sky.  You’re hitting them at their population source.  Milky spore is applied in one season, and the resulting control can last upwards of 20 years. 

The product works like so: after being eaten by a grub, the bacterial spores have nothing short of a cataclysmic orgy.  The resulting exponential growth results in billions of new bacterial spores.   And we thought rabbits were bad!  The inner fluid of the grub, or hemolymph, is so saturated with spores by the time it dies that it turns white, hence the milky nomer.  Therein lies the catch-22: for the bacterial population to grow, it requires live grubs to percolate it’s population.   Meaning, if you don’t have a good infestation of Japanese Beetle grubs, the product won’t flourish well.

Milky spore is available in a powder form in most garden centers.  Spread it on your lawn while temperatures are still warm.  Spore development is optimized when the soil temperatures are between 60 and 70 degrees farenheit.  I found a 40 oz package of powder for $70 on Amazon.  Certainly not cheap, but if you divide the cost of the investment over the span of 10-20 years, it’s a bit easier to swallow.