They're back...

On May 15, 2011 I wrote about the California Oak Moth  as it decimated (not permanently) our Carmel Valley oak tress and dropped it larvae (tiny caterpillars) on my head and into my evening cocktail.  I followed the law of the land and did nothing.  Oh I swept and blew and hosed, but they just kept coming.  At the height of the larvae growth they formed great curtains of webs that made the stately oaks look like Halloween decorations out of season.  They lasted a good portion of the summer of 2011. Frankly we stayed out of the Valley last summer.  They won.

We arrived last week after a month’s absence and in that month they were back.  Not as many, but enough to cover rails and fall on you.  Lounging on the outdoor decks was out of the question.  Time to fight back!

I came across the services of Charlie Phillips company, Stillwater Landscaping & Maintenance.  Charlie has the non-toxic method of eliminating the oak moth larvae.  It’s important to note that although we are now interested in death for the oak moth, we would rather stay away than use a method of eradication that hurt other bugs, birds, or wildlife.  Charlie, and some research proved that he’s the man.  Charlie uses Btk.

Bacillus thuringiensis kurstaki (Btk) is a subspecies of a naturally occurring bacterium, Bacillus thuringiensis, commonly found in soil and plants. It is used as a biological insecticide to control crop-damaging moths.  Btk affects only leaf-eating caterpillars. It has no effect on adult insects. Btk does not kill the insect on contact, but instead must be ingested to be effective. When ingested, proteins produced by Btk that are harmful to caterpillars damage their digestive systems, causing them to stop feeding and die. This effect is specific to the caterpillars. The digestive systems of humans and other mammals differ from caterpillars, and as a result, they are not harmed by the proteins. Humans and other mammals have highly acidic environments in their stomachs that destroy Btk before it can causes infection. Because the Btk endotoxin requires extremely alkaline conditions to become active (such as those found in the guts of gypsy moths and other caterpillars). Btk does not affect animals with acidic stomach environments such as birds, fish, and mammals.

Charlie says it takes about 6 – 10 days for the catepillars to get sick and succumb to the bacterium.  I am leaving the Valley today but will be back in a couple of weeks.  Hopefully I will be sweeping up he mess.