Bugging Your Garden
by Jack Shoultz
Originally published in American Rose
by Jack Shoultz
One of my most memorable moments in gardening was the first time a green lace wing fluttered out from a rose bush. This sight seemed to be one of those times when what you are doing is validated. I had been working on returning my yard to as natural a process as I could. I had thrown out or given away all the "chemical" products that had accumulated over a 3-4 year period. I was even beginning to doubt the methods I was presently using because my results were not exactly what I wanted. My roses had been looking good for a while, free of the major diseases like mildew and rust, but my insect population seemed very one sided. I was water blasting as often as I could while working swing shift or graveyard whichever it was at that time. But it seemed that the aphids were back as fast as I knocked them off. So it was a thrill to see the luminous green wings fluttering through the garden, bringing me one step closer.
Since then I have enjoyed watching a procession of insects come and go throughout the seasons. I soon learned that buying a cup of ladybugs from the nursery and expecting them to stick around to take up residence is wishful thinking. But I did feel good about setting them free and I am sure that someone's garden benefited. And sometimes a few did hang out for a while. But from my experiences came the knowledge that beneficial insects will not take up housekeeping where there is not a ready food supply. That is part of the paradox of Mother Nature. The ladybugs are not waiting in hiding for an unsuspecting aphid to appear. They are out searching for them. The aphids upon reaching your garden somehow, as if my magic, set up base on the new growth and start doing what they do best. When you first notice the aphids they may already have more then a generation in the area. The reproduction of aphids is a remarkable example of how one female can produce thousands of offspring in early spring. The rate if not kept under control can really damage a plant. (This procreative process is characteristic of many insects that attack roses.)
By now you are asking yourself, "Where are the beneficial insects to control these damaging insects"? They are checking out the neighborhood and as soon as they find a food source they will settle in. By the time the "good bugs" arrive, you may already have what you might consider an infestation and realistically damage could be done before your garden environment can balance itself. The new "good bugs" arrive, but will need time to have young to help get the large number of pests under control. Spraying with chemicals will not help, as you are killing the good as well as the bad and when the next batch hatch out the pattern starts all over again.
So what can you as an organic gardener do to help? The first method of defense that I use is water blasting. This is the simplest and least offensive control there is. There are many good tools to use, but I made my own blaster and it fits my needs. I don't like bending over to get on the under side of the leaves at the bottom of the bush, which is usually where a lot of the bugs are hiding or laying their eggs. So, I took a 3' - 4' length of 1/2" PVC pipe (depending on how tall you are), attached a connector for a garden hose to one end with plumbers glue. On the other end, I attach a fitting for an irrigation nozzle. I use a 90 degree nozzle, that way I can focus the spray where I need it and it gives a strong enough blast to do the job. (Email me if you need better details, but this one should cost about $10 to make.)
This method of knocking off the bad bugs will help to keep them under control until the good bugs can catch up. Becoming familiar with all the bugs in your garden - Good and Bad - will help you to know what plan of action will best help. (I only had to water blast once this spring, before my garden reached balance.)
We all know what ladybugs, green lace wings and aphids look like, but are you aware of what the green worms are that are eating your buds or lacing the leaves? The ladybug lays about 20 yellow, oval shaped eggs in clusters usually on the underside of the leaves. When it hatches, it is "alligator-shaped" black with orange spots. Its size is from a few centimeters at birth eating itself up to 1/8". They will be at that stage consuming aphids, scale and other soft bodied insects for 12-14 days. Then pupate to the adult and continue eating.
Hover Fly Larva
I recently saw a green worm on a rose bud, but on closer inspection saw no damage and it was not eating the bud. I took a digital photo, went home, downloaded the image, did a Google search and found out that what I had observed was the larva of a Hover Fly (Syrphidae). On looking at the image on my computer, I realized that this "green worm" had a yellow stripe on its back. Although the fly feeds mainly on pollen and nectar, the larvae can consume hundreds of aphids in a month. I confess that in the past, I had squashed some of these mistakenly thinking it another "bad" green worm. So not all is as it seems in nature. To assume, that just because it is a little green worm it is bad, is not necessarily true. I learned a very important lesson from this and am now taking more pictures and doing more searching. I don't judge a bug by its outward appearance. In fact, I have a picture of a little red worm that I am searching out now. (There actually is another fly that is a predator and that is the tachnid Fly - There are probably a lot more than I am aware of.)
But, there are those other green worms such as the "rose slug". This pest is the larvae of the sawfly and damages your rose leaves, leaving them looking lacy with a cellophane texture. Because it looked like a worm many people sprayed chemical sprays they used for caterpillars only to realize that it didn't work. The fairly recent discovery of Spinosad has been a great boost for anyone needing help in combating this green worm. Spinosad is man made and a bacteria, and is deemed a good product by organic standards.
Spinosad works on all chewing insects, but make sure to spray the underside of the leaves. One caveat is that it will stun honey bees if sprayed directly on them, so the best thing to do is avoid spraying when they are most active (early morning and early evening best). I know of two products utilizing Spinosad. Green Light has one in most nurseries. Rosemania has Spinosad under the name Conserve. I have used them and find that both work. (There may be more sources in your area.) Since it only affects chewing insects there is no damage to the beneficial insects. (If any of you have tried this product against the Japanese Beetle, let me know your results. The bad part about this is that they still have to ingest it to be effective so there will be some damage. If it can slow the population, it may be of benefit.)
In my garden I grow many types of butterfly and bird attracting plants. When the small finches make a pass through my garden a twittering, fluttering and generally raising a ruckus, I watch them go up and down the roses just eating away. When they are done and moved on, the silence means there are less bugs then before. Birds do not make a noticeable impact in any war on bugs, but anytime I see one with a grasshopper in their beak, they get a thumbs up from me. Just enjoying the music they make, the grace of their flight, the fights at the bird feeder, and watching them raise their young make me appreciate more my methods of gardening.
Many butterfly larvae have voracious appetites, but generally don't bother roses. Instead, they will choose their host plant. Spraying your roses would not really affect them as long as "they" follow the "rules". Of course, there are exceptions, as in the cabbage loper or moth. This small white moth, with a black spot on its wings can be seen cavorting in many gardens now. They flutter around and lay an egg here and there to allow the larvae their own leaves to destroy and generally mess up any plant they hatch out on. They can be controlled with general applications of Spinosad, about every 2 weeks. Or as soon as you see the start of damage, you can apply Spinosad or try picking them off or squashing them.
The method and regularity depends on the level of damage you will accept. Which is basically what organic gardening is all about. With the new earth friendly products we have, it is a choice as to how much you want to do to achieve your acceptable results. One result, I couldn't accept was being stung by a wasp or yellow jacket. I normally don't bother them as they are good for the garden. Well, this day my wife was washing off the front of the house and without knowing it hit one of those paper wasp nests and they took out after her. I came around to see what was going on and they came after me. One got under my glasses and stung me about 1/2" below my eye. Needless, to say that nest is gone. I discourage their nest building if they are in an undesirable area, but I still have respect for wasps and bees and what they do.
There is a family of wasps called parasitic wasps. They search for a host insect such as aphids, whiteflies, scales, leafminers and caterpillars and lay their eggs in or on the body. When the egg hatches they kill the host as it is their food source. These wasps are of various sizes, but are rarely seen.
Any discussion on life in your rose garden wouldn't be complete without mentioning spiders. I think everyone knows that spiders do a lot in the ecosystem of balancing out nature. I'm not crazy about walking out in the morning and running into a web full face, but their value far outweighs the down side.
There are more living parts to a garden, but realizing what are good and how they help makes letting them exist an integral component of your reaching that balance. This can be achieved by a little patience, ingenuity and knowledge. I hope that sharing my experiences with you will bring about more interest in finding out what good guys you have in your garden.
Photos from Wikipedia