Biological Balance in our Landscapes

The other night I went into my kitchen to get something to drink. I had left the lights on, and when I walked in I noticed a bunch of insects on the outside of my window, drawn there because of the light. I grinned and started counting, because I knew I?d be writing this article soon. There were thirty Lacewing adults hanging on the glass. In case you?re not sure what they look like, let me describe them. They?re the light green flying insects you commonly see around porch lights at night, about 3/4 of an inch long, with slender bodies and what appears to be two clear wings folded along their backs. Thirty adults who will lay eggs all over my yard, and those eggs will hatch, and little pincher laden larvae will crawl all about, sticking aphids and other soft bodied prey with their jaws, and sucking out all the juice! Biological control in action, and a miniaturized version of the movie Alien!
 
When I care for a landscape, I like to think of it as a mini-ecosystem. Because I want my landscapes to perform well without too much from me, (hey, at least I?m honest), I want to get nature working in my favor. A biological community exists within these landscapes whether I like it or not, and I?d like to have as many of those little critters as possible working for me. You know who I mean?the bugs?or, more accurately, the legions of insects and other arthropods.
 
There?s an old gardener?s saying that goes ?If you kill a spider, plan on doing his work for him?.
 
The further I get away from using chemical control for pest problems, the fewer pest problems I seem to have. It?s really amazing. I undertook my holistic approach to pest control mostly on principle. I?m honestly concerned that our reliance on chemicals has many potential consequences. I really do believe in the ?think globally, act locally? approach to living our lives in a responsible way. So, when I stopped using chemical pesticides to ?control? pest problems, I did it with altruism and hope, but also a dash of healthy skepticism. And here I am, years later, with thousands of dollars saved and healthier plants, to tell you that it works!
 
The thing about most pesticides is that they?re usually pretty non-selective in who they kill. They?re often just as likely to kill your predators, as they are to kill your pests. Unfortunately, the pests usually have a much more rapid reproduction rate, while the predator populations take much longer to recover. So when you?re done spraying, and you?ve inevitably missed a few of the bugs you set out to kill, the populations return with a vengeance, and often the problem is even worse than before, for the predators aren?t there to help keep them in check. So what do you do then? Why, spray again, of course! You see the nasty little cycle here, don?t you?
 
Like many others, I have bought ladybugs in the past, let them go in the evening, and ventured out the next day to check on them. I found just a few. Most of my treasured little helpers had flown away to other yards (the little ingrates) and were helping to control my neighbors? pests. I?m sure some of my neighbors rewarded them by spraying them with pesticides. Unfortunately though, my neighbors, as far as I know, didn?t return the favor by also buying ladybugs so some of theirs would fly into my yard. I was disappointed. Fortunately, biological control has progressed far beyond that point since then, or at least my understanding of it has.
 
I remember the first time I bought insects in quantity. I was taking care of a site with thirty-five Mesquite trees all in a row. With some help, I?d been spraying there for months on end, trying to take care of a problem of little psyllids that would suck so much of the vital juice out of my trees, that the leaves would brown and fall off, and the branch tips would not form properly. While it seemed that the pesticide applications would help alleviate the problem for a short time, within a week or two things would be just as bad as ever, and I was out there spraying again. So I talked to my supervisor and asked him if I could buy some bugs...$400 worth! After he picked his jaw back up off the floor he listened to my idea, and to my surprise and his credit, he okayed the purchase. A few days later, some 13,000 Lacewing larvae arrived. I started to release them on the trees, and curious as to what would happen, I watched the little guys start to spread out. To my dismay, the first one I watched was almost immediately attacked and killed by an ant. Whoa! Time to rethink. Of course the ants would fight the larvae, for they were up there milking the psyllids for honeydew, and protecting them. I immediately went and purchased sticky goop to apply in a band around the base of the trees to keep the ants off, and went back the next day and tried again to release them. This time they seemed to wander off more or less unmolested. Over the next few weeks the psyllid problem virtually disappeared. To top it off, we saved money both in time and chemicals, more than enough to pay for the larvae purchase, and both the workers and the public were safer, in that no pesticides were applied.
 
Since then, I?ve become a convert to cultural and biological control of pests in the landscape. The garden I work at now, the Desert Demonstration Garden, is almost completely free of the use of pesticides, and the plants rarely show any extensive or noticeable damage from pests. Along with preventative releases of Lacewing larvae (they seem especially effective in keeping our roses virtually aphid-free), we also use water extensively in our program. Sometimes we just blast the little buggers off our plants with hard jets of water, (really messes with Spider Mites), or we mix up a soapy concoction that coats their little bodies so they can?t breathe, and I?ve heard it makes the plants taste bad as well. I?m not sure about the last part, but it does seem to make sense. Another control method we use is the placement of yellow and blue sticky trap cards throughout the Garden. These attract the pests with their bright colors and they get inextricably stuck to them. They?re also useful in that they allow us to do some monitoring of our pest populations, simply by observing the numbers and types of insects stuck to them.
 
There are a number of companies out there that will help you in selecting the right control method for your pest problems. I?ve found the folks at Rincon-Vitova to be particularly helpful. They?re an insect producer in California. There?s also a wealth of information available to us on the web, and other helpful vendors. So, do a little research, and see what you can find as an alternative to our tradition of spraying every time we see a bug. I really believe that like me, you?ll be pleasantly surprised by how effective these non-toxic control methods are. And may the bugs be with you!