Beneficial insects: bug your bugs

Biological alternatives to chemical pesticides are gaining wide popularity in the agri-cultural industry. Take advantage of these non-toxic techniques in your backyard plot.

by Karla Stange
f you are a gardener, you understand heartbreak and frustration. It's that pain you feel when you check the lush tomato plants you lovingly tended all summer, only to find the bright red fruit blighted with worm holes.
Your first angry response may be to grab the nearest pesticide and spray away. But if you are like many other environmentally sensitive people, the use of chemicals in the home garden may cause a pang of guilt.
It's a tough decision. You can't live in peace with the litte beasts that ruin your prized fruits, vegetables or flowers, but you don't want to wantonly spread poison all over your yard either.
Beneficial insects may provide an ideal solution. You may already know about some of these "Terminator" bugs: praying mantis, ladybugs, decollate snails and beneficial nematodes. In addition to these faithful predators, there's a whole army of lesser-known insects that can be ordered through catalogs (see Call to action, below) to help you maintain order in your garden.
The concept of using beneficial insects as "biocontrol" is simple: increase the ratio of predators to prey and it will create a natural balance that will protect your garden. When used in conjunction with other new organic and non-toxic garden products like insecticidal soaps and sticky traps, beneficial insects can provide efficient and environmentally safe pest management.

Ag industry uses 'good' bugs

The beneficials that you find in commercial nurseries have first been extensively tested on farms. Due to the growing public concern over the use of pesticides, many growers have started searching for organic ways to protect their crops. The agricultural industry currently uses many benefical insects to control stubborn pests, and the trend is likely to continue.
Don Domenigoni, an entomologist and Agricultural Standards Investigator for the County of Riverside Agricultural Commission, believes beneficials may be one of the key elements in a new system of biocontrol. "If the growers can get an integrated pest management control program going, it would not only benefit the environment, it's also going to benefit them economically." Growers are faced with tougher pests that have developed a resistance to chemicals, so they are turning to beneficials instead of larger and more expensive amounts of pesticides.

To spray or not to spray

The insects that have been proven to work in the field are slowly entering the commercial market, and recreational gardeners have shown increasing interest. "Once people know about biocontrol, there will be a demand for it," said Domenigoni, "because that's what the Green movement is all about - consumer support for products that won't hurt the environment."
You may think of your backyard garden as a peaceful paradise, but under the leaves and within the soil, there's a raging battle for survival. An army of aphids, worms and beetles struggle to find food, which, unfortunately, may be your neat little rows of peas and carrots. One way to get rid of the pests instantly is to use pesticides. Sure, this gets rid of the bugs, but it also may contaminate the water your cat drinks, or kill the birds who eat the dead pests, or even poison the air you and your children breathe. One bottle of pesticide can create a dangerous chain of reaction.
Lou Diaz, Manager of Mission Hills Nursery in San Diego, is concerned with the commercial misuse of pesticides. "People don't always read the warning labels that say 'Don't release near streams or ponds,' or they don't wear protective clothing when they spray. There can be some dangerous exposure." For people who are concerned about chemicals in their environment, beneficial insects can be the key to a new way of protecting home gardens. "But you pretty much have to decide one way or the other - beneficials and biopesticides or chemicals," said Diaz. "The reason is that you'll kill off your beneficials along with the harmful pests if you use even the smallest amount of pesticides."
Using biocontol measures, on the other hand, means that your actions are in tune with the natural cycle of life. While pesticides are like an atom bomb, eradicating all insect life for an extended period of time, beneficial insects work like little hitmen, selecting out only the pests that are causing problems in your garden. "Like any predator-prey relationship, you have peaks and valleys in the populations. Bio-control is never absoute or eradicative. The beneficials are never going to kill totally all of their prey. But they will kill enough to keep the pests from destroying your crops," said Domenigoni.
If you are a person who demands quick results, however, using biocontrol methods may be frustrating. "For people who want instant gratification, biocontrol is probably not a good idea. While pesticides take a few minutes to kill the pests, beneficials take a couple of weeks. But if you set out beneficials while the plants are young, before a pest problem is out of control, then you'll see good results," said Domenigoni.

Buying the best bugs

It may seem strange to spend money on a carton of ladybugs, or a little box of decollate ("carniverous") snails at your local nursery. There is also a parasitic wasp on the market now where you buy an empty box, send it to a certain address, and it comes back to you full of egg cases ready to be hatched.
For those who are a little squeamish, handling insects may be a major detriment to starting a biocontrol program. But consider the rewards of using, for example, beneficial nematodes to protect your lawn. "A lot of people have problems with grubs in their lawns during the summer," said Diaz. "Then you have two problems, because grubs attract skunks, who like to dig for them. Beneficial nematodes get rid of the grubs, protect the lawn and prevent skunks from dining on your property."
According to Diaz, nursery customers are now asking for certain beneficials by name, instead of automatically reaching for pesticides. Decollate snails, which eat the common brown garden snail, are popular because snails can be difficult to control, and baits and sprays may not get rid of the problem. Decollate snails also offer another benefit: after they have eaten the garden snail population down, they feed on organic material like dead leaves, which adds to the natural composting process.
Most of the beneficial insects are available in nurseries only in the spring and summer seasons, but now is a good time to plan a system of biocontrol for next year. "Talk to a local nursery-person who is familiar with the products. They can help you figure out which pest you're trying to get rid of, then recommend the appropriate beneficial insect," said Diaz.

Practical tips

You may be thinking: "I hate bugs, why would I want to add more to my garden?" With a good system of bio-control, you won't even notice the tiny insects that will protect your plants. There won't be any black clouds of insects swarming around you, invading the peace of your garden. In fact, you'll feel more relaxed, knowing that you don't have to keep the kids or pets away from areas previously sprayed with chemicals.
Here are a few tips on how to use beneficial insects in your garden:

1. Target your pest.
Think about what fruits, vegetables, or flowers you are going to plant, and do some investigative work on which pests in your specific area tend to be a problem. With the help of a nurseryperson, choose a beneficial insect that will go after these pests. Think of it as a food chain game matching predator to prey.
2. Create an attractive environment
For bugs, this means plentiful food, water and shelter. One way to encourage the process is to have a permanent border of weeds or native plants around the area you want to protect. Although cultivating weeds may not appeal to your aesthetic sense, it will help to keep your garden protected and free of chemicals. An occasional sprinkling of water on these sheltering weeds will provide enough moisture for your beneficial insects to thrive. If you create a good environment, your beneficials may breed and reproduce, which will create a perennial army of "hitmen" bugs.
3. Avoid any chemicals
Make sure you haven't sprayed or baited for snails in the last six months before you set out decollate snails. Remember, if there is lingering pesticide on your plants and soil, your beneficials will suffer.
4. Plant a succession of crops
For vegetable growers, it's a good idea to plant a series of fruits and vegetables throughout the year. This provides a continuous pest supply as a food source for your beneficials. For example, once your lettuce crop is done, they can move on to tomatoes, and then cabbage, and so on. This will prevent your beneficials from abandoning your garden en masse and moving on to your neighbor's yard once they have eaten a pest population down.
5. Release during early spring to mid-summer
Insects don't like extreme heat or cold, so you'll get the best results if you release them during the mild weather seasons (although with San Diego weather, you may be able to release them year-round). It's also better to release the insects in the early morning or early evening, when temperatures are cool and there is moisture in the air.
6. Watch for the first signs of pests
Don't wait until a pest problem is out of control. Due to the slow process of reducing a population through natural means, you'll probably lose some of your crops. Set the beneficials out either before the problem occurs (this is where the investigative work pays off) when the plants are young, or when you see the very first signs of damage to the plants.
7. Give yourself a pat on the back.

You deserve a little thanks for doing your part to protect the environment. If every gardener starts with their own back yard, it will make a big difference in our quality of life.

Call to action ... What you can do

Call or visit your local nurseries. Many can provide you with professional advice and a variety of pesticide alternatives. Common products include ladybugs and "bt" (a bacillus spray particularly effective against worms and catterpillars).
In the book Sustaining the Earth, Debra Dadd-Redalia calls The Bio-Integral Resource Center "the very best source for practical information on the least toxic methods for managing pests." Members can get advice by mail or phone about virtually any pest problem. The group publishes a newsletter and has a number of pamphlets on pests. You can write them at: P.O. Box 7414, Berkeley, CA 94707, or call (415) 524-2467.
Gardens Alive! is probably your number-one source for organic garden products. While many beneficial insects can be found at your local nursery, if you really get interested in biocontrol, this little catalog offers several "killer" beneficial insects that you can't find in nurseries. You can choose from green lacewings, whitefly parasite and parasitic nematodes.
Gardens Alive also carries many innovative non-chemical pest control products, like traps, sticky bars, and insecticidal soaps. To order this catalog ,call (812) 537-8650.

Karla Stange is an editor for the Times-Advocate in Escondido, an environmental reporter, and a free-lance writer. Raised in Hemet, CA, she moved to San Diego 6 years ago and now lives in Golden Hill.