Beneficial Insects

This began as an update to Thrips :(, but then I thought it might go better as a continuation of Wait! Don't Grab That Spray!.  In the end, I decided to make it its own entry.

It has been a beautiful spring with plenty of rain and the plants are thriving.  One thing plant pests love is new growth, and this year they have it.  I have been finding aphids everywhere, and though I was hoping with all the rain and the virtual flood we had the thrips would have disappeared, they are back, though as yet, damage is minimal.  I have also discovered that they are the reason why my Clematis have done so poorly the past couple of years.

I sprayed some plants with Neem oil, but on most plants it is pointless.  Where do you begin?  Or end? Most everything seems useless with thrips anyway.  My thoughts turned to beneficial insects, particularly for the thrips.  A quick search showed that minute pirate bugs, big eyed bugs, predatory mites and even some nematodes eat thrips.  They cost a pretty penny though, but since there are no assurances that you will get what you are paying for, or that it will be successful if you do, I decided I will try to attract some to my garden.  I have their food source, so all I need are plants that attract them.  Yarrow and shasta daisies are a couple that I already have and are attractive to several of them.  Fennel and Cosmos are a couple of others, so I bought seed and scattered it around the garden.  As I researched beneficial insects, I saw that there are many more that eat thrips, they just are not necessarily ones that are sold.  The best part is, I already have a lot of them in the yard.

The next thing was to hope that lady bugs would discover the feast of aphids in the garden.  Of course, there have to be enough aphids to be an attractive food source for the lady bugs.  In looking in the curled up leaves of an aphid infested plant I saw something amazing.  Tiny lady bug larva.  A few days later in the curled up leaves of another aphid infested plant, the dried up remains of aphids and the skins of lady bug larva that had molted.

A well fed praying mantis.

The closer I look, the more I see a wonderful array of beneficials in the garden.  I discover new ones every day, some insects I have never seen before. As I look them up, I discover others that I have seen for years, but never knew they were beneficials.  There appears to be a wonderful balance in the garden, and though there may be some insect damage, it is minimal compared to the damage that would be caused if I tried to fight the battle on my own with pesticides.

October 6, 2013 update:  I keep check for thrips, and the other day I saw one, the only one since soon after this was posted.  There are also countless beneficials, including minute pirate bugs. Unfortunately cucumber beetles have discovered the roses, but I am sure beneficials insects will reduce their numbers as well.

Also see Why Organic Garden?

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?