Beneficial Insects In The Garden



A few weeks ago I was picking lettuce and as I worked my fingers down a leaf to break it off, was stung by a wasp.  Surprised, I check the plant and found several wasps deep inside the rosettes of several lettuce plants.  Puzzled about why they were there, I none the less let it go and have just been much more careful and observant when picking lettuce.

Well a couple of days ago, I figured it out and the answer is a great example of why we should not use insecticides in our vegetable garden.  Many people who grow vegetables organically do it because of concern about the chemicals they or their families might ingest when eating the produce.  This is a good reason to grow organically, but there is also another, just as important reason.

Insecticides often have a broad and residual effect.  A chemical may kill its intended target, but also kill ladybugs, honey bees, and other beneficial insects.  The latter category of insects turns out to be where this wasp resides.  The wasps were busy down in the center of my lettuce plants helping me to grow healthy productive plants.  It turns out that there were small green caterpillars down in the centers of my lettuce, eating to their hearts delight.  The wasps turn out to be predators of these worms, finding them deep in the lettuce and eating them.

When I first came across one of the wasps on top of a worm, I thought it might be laying eggs.  For example, I had heard of wasps that lay their eggs on the backs of Tomato Horn Worms.  When these eggs hatch, they burrow into the worm and eat it from the inside out.  In this case, however it was obvious the worm was dead.  As I watched I could see that the wasp was slowly devouring the worm.  So, now the wasps are my friends, joining me in my quest to grow healthy, organic lettuce.  Beneficial insects can thrive in a garden free of insecticides, making the organic growers job of getting healthy produce much easier. 

I had another surprise when I looked at the photos I took of the wasps.  I had not noticed the house fly that was in many of the photos, seemingly just observing the action.  Why, I don’t know, unless the fly knows the wasp will leave some caterpillar guts behind for the fly to clean up.

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Will Sig
1 Bob

Too cool Will and very interesting, always amazed at your close ups.

Bobs last blog post..The Great Columbian Mammoth


2 John Hunter

Great post and photos. I don’t use any chemicals on my garden (or yard for that matter) and the garden does very well. The only fertilizing I do is with compost I get from leaves, grass…

John Hunters last blog post..Salaries with a College Degree


3 Linda Prout

A couple of nights ago, the vineyard next to our house near Sebastopol, CA was sprayed in the middle of the night with a variety of pesticides (for fungi and mold). We listened to the aerosol machines from 10pm to sunup.

About an hour after the spraying started my husband felt his throat burn and his sinuses became inflammed and congested. He did not sleep at all that night nor the next, in fact lay awake with his mind racing in way he has never experienced. Two days later, he is still congested and with a sore throat.

And true to Will’s post message, the flowers in my garden that attracted swarms of buzzing honey bees just a few days ago are eerily quiet.

We have always bought mostly organic food. After this little episode we will work toward ONLY organic and never drink conventional wine. The chemicals used in the vineyard (Elevate and Elite) were made by Bayer. They come with a warning to avoid the sprayed field for 12 hours, although Hispanic workers returned early the next morning for pruning.

Isn’t it interesting a company makes one product that causes you to need their other products (drugs). Turns out almost all pharmaceutical companies make toxic chemicals that cause you to need their drugs, whether it be for pain relief or chemotherapy for cancer. I can’t think of a more profitable corporate strategy.

The only way to change this is for every person to vote organic with his or her dollar. The money you save on your health will more than pay for any extra you spend on organic.


4 Will

Hi John – You are right about the compost. We recycle all our appropriate kitchen wast into the compost plus lots of the outside plant and garden stuff. It is the only fertilizer I have to use on the vegetable gardens.


5 Will

Thanks for that comment, Linda. Sorry to hear about the spraying in the vineyard. They really should notify the neighbors. If you had known it was going to happen. a motel in town for the night might have been worth the price.

I am constantly going back and forth about starting a series about the cost of organic food. There are so many factors involved, and some get me really worked up. The bottom line is that as long as the price difference continues the way it is, wide-spread acceptance will be hard to achieve. I bought a whole organic chicken from a local grocery store a few days ago. The price was 2.28 per pound. On the display shelf right below the organic chickens were the conventional whole chickens at 78 cents per pound.

At almost 3 times the cost, how many people do you think are going to buy the organic chickens. I did, but I bet 99% grab from the lower shelf and I can’t say that I blame them for making that choice.


6 Linda Prout

I have purchased organic chicken at Whole Foods for 99 cents/lb. They run sales periodically and I’ll buy up 4-5 whole chickens. If you buy sale items in larger quantities, you can do organic reasonably. Whole Foods has $1 off coupons for organic butter right now. I just bought 4 packages and stuck 3 in the freezer. I scan the whole store and buy up the discounted items I normally use. McEvoy Organic Olive oil was recently reduced by 1/2 at another local store. I bought 4 bottles. If you shop like this you can live on organic foods relatively inexpensively. Especially if you skip your daily Starbucks fix. One month of lattes comes out to $75-$90. You can buy a lot of organic chicken for that.


7 Jennifer Robin

You can imagine the mess we had in So Cal back in the 80’s when they were aerial spraying with malathion for the Mediterranean fruit flies. We didn’t see bees or ladybugs for a few years.

I love our 42 acres in the woods all the more because of that past life. Everything within our sight is a perfectly balanced part of the ecosystem, bugs and all.

Jennifer Robins last blog post..bookMobile Monday: Remember When?


8 Andrew Flusche

Simply amazing!! I love the photos of the insects. Although this reminds me too much of picking lettuce when I was kid. My dad liked to plant lettuce, and I hated picking it. Hard, nasty work.

Andrew Flusches last blog post..Quickly E-Sign Your Business Contracts


9 Will

Lettuce? Hard? LOL! I had a job in college where some days I picked bush beans for 8 hours. Now that is hard. Oh, and yes, I also walked 10 miles to school every day, uphill both ways, in all weather. 😉

The beans part is true, though.


10 Steve

hi Will,
Beautiful picture of the wasp and nice post as well. I’ve never thought of a wasp as being “beneficial”. I do think of spiders in a beneficial sense,and remind my wife that they eat bugs and such, but until now, I’ve just thought of wasps as a typical “pest”. I’ll look at them a little differently from now on.
I’d be curious to see if you can change my opinion of gophers though, based on the havoc they can wreck on a yard and seeing whole squash plants sucked down into the ground and disappear… ~ Steve


11 Brian

I just about had a similar incident several weeks ago when trying to gather some blackberries. I reached in to grab a few ripe blackberries and at the last second noticed an actual wasp nest, covered in wasps, that was constructed under the dense canopy of leaves. Even though no wasps flew my way I still took off like a bolt of lightning. These weren’t the beneficial wasps I like to find in my garden, but I left them be just the same. We try to refrain from using chemicals in the garden as well. I think we all get enough toxic chemicals from what we have to buy at the grocery. No need to add them to our home-grown food.

Brians last blog post..Garden Reflections


12 Gloria

When I first started gardening I had to get used to working through all the bugs and knowing which ones to keep and which ones to get rid of. It was hard to adjust to it and I love many plants. But now I have a thriving garden.
.-= Gloria´s last blog ..How To Replace Garden Canopies =-.


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