2015-05-18

Columbines In Spring

Spring sprang kind of quickly on me- with an attack on my columbines. I have to admit I didn't look closely enough in the beginning- attributed the mounting damage on the leaves to wind and sudden heat but by the time I really did examine the plants it was almost too late. Tiny little green caterpillar-like insects were chewing up the leaves- dozen of these things from what I could see and I knew that there must be far more that I couldn't see.
17 crawlers in this closeup
It was really discouraging because this had never happened before since moving to Merritt- with the exception of the aphids on the apple tree that we eventually took down. These were sawfly larvae and as far as hatches go there might have been several...it was bad.

So there I was, standing over the carnage, debating the wisdom of not using chemicals and an idea struck me. Thinking about how diatomaceous earth was a good control for ants I thought there must be something similarly natural that could take care of these creatures. (Diatomaceous earth is basically super finely ground up diatoms- ancient calcified sea creatures- that effectively becomes powderized glass that ants ingest and die from).
Leaves stripped and ongoing damage
I wondered if talcum powder would work and got some from the house and  blasted one plant with it as a test. I checked back in 5 minutes and after a moment saw a small caterpillar fall off. I came back 5 minutes later and saw a few more on the ground at the base of the columbine.


Made up my mind and blasted every plant with the remainder of the powder. At the end of the day there were easily hundreds of larvae on the ground...the ants came and took a few away but most of them I simply hosed off. I went to the dollar store the next day and bought more talc and blasted the columbines twice more. In the end I believe several thousand larvae had contributed to the excessive damage- this was just over a week ago and most of the plants have recovered and are beginning to flower but the damage still shows.
Talc to the rescue!
Talc is a fairly natural substance in that it's the softest mineral on earth and is ground up very finely and usually has some scent added. Obviously you don't want to breath it in so  apply it on a day when the wind isn't blowing. The fine powder gets into the spiracles (breathing parts) of the caterpillars and clogs them up and possibly poisons them as well. I was able to do this on a relatively cool overcast day so there weren't any other insects moving about in the garden for which I'm grateful.

Too bad, so sad

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