Thursday, March 12, 2015

Tolerating the Uglies, Take 2

Probably the hardest lesson I've learned in gardening here is to tolerate the uglies caused by blister beetles.

Our vegetable garden was one of the first gardens we began after moving in during the spring of 2007.  Having just spent 6 years in southern Alabama, where tomatoes didn't grow very well, we were aching for some sweet-tart, juicy, home-grown tomatoes - and therefore tomato seedlings were some of the first plants that went in.

The tomatoes did beautifully...except that they got pretty ragged looking in late summer, in large part because of all the blister beetles - both black and gray - that were munching on their leaves.  Mind you, the plants were still producing huge numbers of tomatoes.  There were more tomatoes than we could possibly eat or even give away.  But, doggone it, the plants looked positively decrepit, with ratty leaves, covered in blister beetle, frass.  How could I call myself a gardener with my tomato plants looking this bad?

So in I rushed, intrepid organic gardener to the rescue!  Every morning I would fill an old peanut butter jar half full of water with dish soap in it and sally forth to fight the blister beetles.  Carefully I inspected the leaves of the tomato plants and gently picked off the blister beetles, dropping them to their soapy deaths in my peanut butter jar.  At first I wore gloves, worried about the defensive chemical, cantharidin, that blister beetles are known to secrete.  It's cantharidin which will cause the blisters that earn this group of beetles their family name.  Eventually, though, I shed the gloves and still had no problems.  It wasn't uncommon for me to pick 50 or 100 blister beetles off my tomatoes each day.   Best of all, I could simply flush the dead beetles down the toilet or even put them in the compost when I was done, since my "killing agent" was simply dish soap and water.

Faithfully I protected my tomato plants for several summers this way, culminating in 2011, when we came home from a trip in early June to find several huge masses of Three-Striped Blister Beetles engaged in orgies on our front lawn. 

I'd not seen ONE of this blister beetle species in our yard before, let alone thousands of them.  What should we do?!  What if ALL of these guys started eating the plants around the yard?

Getting creative, I put my soapy water solution in a small shop vac and we vacuumed most of the striped blister beetles up.  Whew.  Disaster averted.

But, wait.  No.  Disaster NOT averted.  It just wasn't the disaster I thought I was getting.  Up until this point, we hadn't had any real issue with grasshopper populations, despite living in the country and being surrounded by tall grass and crop fields.  Beginning in 2011 and continuing into the present, we've learned the benefit of blister beetles.

You see, blister beetle young (larvae) burrow through the soil and eat grasshopper eggs.  For every adult blister beetle you see, 21-27 grasshopper eggs have NOT grown up into grasshoppers.  And those 21-27 grasshoppers that haven't grown up also haven't produced any eggs or young of their own.  While blister beetles eat leaves for a few weeks and make them look pretty ugly while they are munching, they don't generally eat a wide variety of plants and they don't even defoliate the ones they do lunch on.  Grasshoppers, on the other hand, will eat almost anything, including bark, and they will eat it all down to nubs.  The photo below shows what they did to our (shrub) althea one summer.....

Weather certainly played a role in our grasshopper outbreak, but I'm quite certain that our grasshoppers wouldn't have been as numerous if I hadn't been so zealous about controlling the blister beetle populations in our yard.

Blister beetles have now become almost a sacred animal around here.  I welcome them to the yard when I see them, and I mentally encourage them to munch for a while.  Happily, I've been seeing a few more blister beetles each year.  I still don't see three-striped ones, though.

Meanwhile, last summer had wet spells.  It turns out that, during rainy spells, grasshoppers get a fungus which causes them to climb to the top of plants, grasp the stem firmly,... and die.  Our yard was full of these weird grasshopper mummies gruesomely hanging on to the tips of plants. 

Between healthier blister beetle populations and grasshopper reproduction being down due to the zombie fungus last year, I'm hoping there will be fewer grasshoppers overall this summer than there have been in recent years.

I'm hoping, too, that the blister beetle populations will once again be healthy and that our tomato plants will look quite ragged by summer's end.  From now on, the blister beetle "uglies"  will be welcomed with open arms in our landscape!


Corner Gardener Sue said...

Oh, my! I didn't know about blister beetles controlling grasshopper populations! I used to pick insects off of plants, too, but not consistently. I do cut baptisias with the genista broom moth caterpillars on them and put them in the trash. I didn't have to do it last year, though.

I am tickled with the variety of insects and a few birds that seem to carry on OK in the yard.

Gaia Gardener: said...

Sue, It's absolutely amazing what I've been learning about the insect life in my yard! Almost all of the new insects I find (and photograph) have turned out to be predators or parasites, often controlling plant eaters like grubs or caterpillars. It's truly heartening...and sad, because so few people realize how helpful these many insects really are.