Central San -- Education:Less-Toxic Home & Garden - Beneficial Organisms
2/22/99


Types of Beneficials

Use beneficial organisms to control pests.


If the native beneficial organisms (beneficials) in your garden need some assistance, you may wish to purchase beneficials. Garden supply catalogs offer many species, and you can purchase them directly from private insectaries.
Know Your Pests
Effects of Pesticides
Where to Buy
Beneficials are Alive
Low Pest Populations
Habitats
Keep Ants Out

        Types of Beneficials

Beneficial organisms fall roughly into 2 categories: predators and parasitoids. Predators are usually generalists and feed on a number of different pests. Parasitoids are more specific and many can develop in only one host species. There are many predatory and parasitic insects, but there are also predatory mites and beneficial nematodes (microscopic worm-like organisms).


        Know Your Pests

It is important to have an accurate identification (preferably the Latin name) of the pest you are trying manage, so you can buy a beneficial that actually feeds on it. You can take specimens to the County Cooperative Extension Office, (look under "County Government Offices" in the phone book). Private consultants also provide identification services. See the Yellow Pages under "Horticultural Consultants." Calling ahead to ask when to bring in your specimen and how to preserve it will save time.


        Effects of Pesticides

Most beneficials are extremely sensitive to pesticides (often much more so than pests!), and you may have to wait for pesticides you have used recently to degrade before introducing beneficials into your garden.


        Where to Buy Beneficials

Beware of fly-by-night producers with poor quality products. Buy organisms only from reputable insectaries or retailers that guarantee their products. Is the staff helpful and do they seem knowledgeable? Complete and easy-to-read information on how to release the organism should be included with your purchase. This should cover facts about the life cycle of the creature, specific release rates, how often they should be released, and any special requirements of the organism.

If you are buying beneficials from a nursery or hardware store, ask for the name and phone number of the beneficial producer. Ask the staff in the retail store if the beneficials have been kept in a refrigerator. Don't buy anything that has been stored on a shelf.


        Beneficial Organisms are Alive

Beneficial organisms are living creatures and must be handled with care if they are to remain alive. They will need food when they arrive in your garden, so don't order them unless you have pests for them to eat.


        Some Beneficials Work Best When Pest Populations are Low

You will have the most success with some beneficial organisms (consult the insectary) if you release them at the first sign of a pest problem. This requires monitoring your garden, getting out and looking at leaves and plants to find pests before their numbers reach high levels.


        Create Habitats for Beneficial Insects

Often it is the immature stage of a beneficial insect that provides the best pest control, while the adult feeds mainly on nectar and pollen. By adding nectar- and pollen-rich plants to your garden you can encourage the beneficials to stay and reproduce. Try plants with numerous small flowers such as yarrow (Achillea spp.), sweet alyssum (Lobularia maritima), native buckwheat (Eriogonum spp.), California lilac (Ceanothus spp.), and coyote bush (Baccharis spp.). Flowers in the daisy family, such as asters and cosmos, and herb plants such as fennel, coriander, caraway, dill, and chervil (if allowed to flower) are also useful.


        Keep Ants Out

Many pest insects, such as aphids, scales, and mealybugs, are tended by ants that will attack and fend off beneficial insects. Use sticky barriers (Tanglefoot®, Tree Sticky Barrier®) around the trunks of trees or shrubs to exclude ants. Prune branches away from buildings or other objects that might provide ants an alternative route into the plant.




Business | Residential | Student | Publications

Services | Sewer System | Organization | Education

© 1999 Central Contra Costa Sanitary District.
All Rights Reserved, Email : Central San