Flea Beetles, Biological Controls, and the Peter Principle

I would like to speak to someone in charge.  I ordered this: 

Instead, I got this:

The flea beetles are feasting on Salix alba 'Britzensis', aka coral bark willow.

The following rant is dedicated to the people who make a living making you feel bad, the authors of what I like to call the Fantasy genre of garden literature.  They hold out the promise that if you simply do A, you will surely get B.  They also have a warning: whatever you do, you must never do C.   

Tiny but ruthless. Flea beetles are particularly fond of Rudbeckia 'Goldstrum.'

For the past two months I have been suffering from a flea beetle epidemic.  The trouble started, as usual, on my Rudbeckia, one of those "indestructible" natives you're supposed to plant to get that Snow White effect.  If you think that flea beetles only like eggplant, think again. They adore Rudbeckia.  

I wanted to give peaceful co-existence a chance, so first I tried flicking them off.  But it turns out they are a very mean-spirited bunch and used my "walk softly" approach against me.  If you drive them off one plant, they attack another.  That is the nature of flea beetles. 

Achillea "Strawberry Seduction" is here to attract beneficial insects. Plus it's pretty.

Flea beetles are almost impossible to eradicate, unless you intend to pull a Monty Python and bring out the heavy artillery.  But who thinks in terms of eradication? All I wanted to do is control them, and that's hard enough.  For starters, they seem to be impervious to biological controls.  I should know.  I have more biological controls than you can shake a stick at.  I've got bees buzzing, butterflies fluttering, and birds chirp-chirp-chirping.  I have all kinds of beneficial insects, hundreds of frogs and lizards, and the occasional box turtle.  Snow White has nothing on me.

Yet it turns out that even biological controls are subject to the Peter Principle.  They are effective up to a point, but eventually they meet their match.  In my case, their match was the flea beetle. 

Displaced from Rudbeckia, but moving on to Achillea.

With the birds on strike, Nepeta (which is said to repel flea beetles) entirely useless, and soapy water a joke, it was time to step up the program.  Neem, which supposedly makes the plants taste bad, held them at bay for a few days but had no long term effect.  Dusting with diatomaceous earth helped with the Rudbeckia infestation.  However, it did nothing to help my coral bark willow, where hundreds of beetles were massing along the branches last week, decimating the foliage and withering the stem tips.  

A few survivors linger on the coral bark willow.

There is an old Henny Youngman-style joke that goes something like this: if a husband speaks in the forest and his wife isn't there to hear him, is he still wrong?  By the time I reached for the pyrethrin, I felt a lot like the husband in the forest. Whatever I did, I was going to be wrong.  

The pyrethrin worked.  The flea beetles are (mostly) gone.  All that's left are an inferiority complex and a guilty conscience.  Nice going.