Monday, June 25, 2012

Wait! Don't Grab That Spray!

Some of my Clematis have been looking a bit chewed on lately.  The other day I was looking closely to find the culprit and I saw an odd looking bug.  A lot of people's first response would be to grab the spray, and the thought did cross my mind, but I chose otherwise.  I observed it for awhile and noticed it was looking for something.  If it was the bug who had been chewing on my plant, it would need to look no farther to chomp down.  There was only one of them and bad bugs are rarely alone, so I thought the odds were good that it was a beneficial insect looking for a meal. Examining it closer, it looked like the larva of a lady bug, though it was a different color than I was familiar with.  I had seen a feast of aphids on another plant earlier, and knowing that is a favorite meal of lady bugs and their larva, I took it to them.  Sure enough, it quit searching and munched down.  Had I jumped my guns and sprayed him, I would have been killing my ally and helped the bad guys to grow in their numbers.  That was a lesson learned the hard way.

Lady bug larva on an aphid infested Asclepias.

When I first started gardening, I decided I was going to have the "perfect" garden.  I went to the store and bought a bunch of herbicides and insecticides to kill everything that did not belong in my garden.  The clerk told me that was not a good idea, but what did he know ... he was a chain store checker.  Every day I went outside and diligently sprayed every cucumber beetle and squash bug I could find.  I was going to win this war and have all kinds of veggies, and it seemed to work for awhile.  Key words, "seemed to" and " for awhile."  I went out one day to find pitiful looking plants covered in what I learned to be aphids.  At that point, the battle was over, the bugs won, so I backed off on spraying.  A short time later I was looking and saw a bunch of terrible looking bugs I had never seen before.  These little alligatorish looking bugs had to be bad and I just about grabbed my spray, but my curiosity was stronger than my desire to kill them.  I looked page by page through an old insect book until I found a drawing of what I had seen.  It was lady bug larva. I read a little bit about them and found that they were there to eat the aphids.  They were my allies!

At that point I began diligently going out daily to flick squash bugs into soapy water and crush any of their eggs I could find.  I learned about beneficial nematodes and bought them to eat the larva of cucumber beetles.  I hardly have a problem with either any more.  I have traps for the Japanese beetles and flies; not only do the the ones I trap die, but the more I trap, the fewer there are to reproduce.  I have not found another way to get rid of flea beetles on the eggplants, but I only spray when they are doing extensive damage.  Likewise, I minimally spray the iris for borers.  I have decided to let nature take its course with thrips on the roses because it seems to be a losing battle regardless.

Whenever you spray any pesticide (fungicide, herbicide or insecticide), it kills most of what you are after. Key word, "most."  Those who survive are resistant and spread, creating super weeds or bugs, etc.  In the case of insects, the spray kills both the pests and the beneficials who feed upon them.  Since there has to be a greater ratio of pests for beneficials to survive, not only do more pests survive the insecticide, they also reproduce faster than the beneficials.  Unless there is great destruction, it is best to leave pest insects alone so the beneficial insects can move in and do their job.

Instead of herbicides, be diligent about weeding and use mulch freely.  One year's seeds is seven years' weeds.  Only use herbicides on the most difficult weeds that cannot be pulled or dug. Remember that not all uninvited plants are bad and biodiversity is a good thing.

When pesticides are needed, they should only be sprayed in the early morning or late evening when beneficials, including honey bees, are least active.  Even organic sprays can be toxic to beneficials.  Avoid spraying when there is a breeze to help prevent overspray.  Always make sure what you are spraying, insect or plant, is really an enemy.  Do not necessarily go for the most toxic spray and ALWAYS USE ACCORDING TO THE DIRECTIONS.  More or more often is not better. In fact, it is worse because it adds to the resistance problem which effects everyone and everything.

Update: July 5, 2012 ... Another unidentified insect that turned out to be an ally.  It looked vicious, but there was only one, so before killing it, I took the time to find out what it was.  While it can inflict a painful bite to humans, the wheel bug (Arilus cristatus) is also a beneficial insect that among other things eats Japanese beetles.

Arilus cristatus - wheel bug nymph
Also see Beneficial Insects and Why Organic Garden?

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