trichogramma | lacewing | lady bugs
Crop Protection Through Biological Control
The economic loss caused by the Bollworm and Budworm to cotton crops is estimated & high as 500 million dollars, and to all crops nearly, 1 billion dollars per year. With more pest insects becoming immune to insecticides, this damage is increasing each year and so is the cost of controlling the pests. Entomologists are searching for new insect control alternatives to replace the chemical control strategies. Although effective and necessary in some cases, chemical applications have been used indiscrimately for too long, and the consequences of this shortsightedness are now upon us. The most promising 'new' method of insect control has been with us for millions of years and is now being 'discovered' by modern entomologists – natural biological control!
What Is Biological Control?
Insects fall into two general categories: (1) Beneficial and (2) Harmful (pest) insects. Biological control utilizes the natural presence of beneficial predators and parasites to reduce and keep the pest insect populations below economically harmful levels. Predators such as the Lady Bug and Green Lacewing devour many pest insects during their cycles while parasites such as the Trichogramma Wasp sting many eggs of potential worm pests during their life cycle.
Beneficial insects do not become pests themselves since they are programmed by nature to adjust their own population to fit those of the pests. The population range of each Insect species is predetermined by nature. When one species increases its population, the insects which feed on that species will increase their population accordingly since there is that much more to eat. When the pest population is reduced to its normal range, the lower food supply will cause beneficial populations to adjust again through starvation or migration to find food elsewhere. Thus the natural balance of nature is maintained.
As you can see from the above, biological control will not eliminate pests, but it can keep their populations below economically damaging levels. Although we tend to consider all insects as pests, fewer than 1% of insects are classified as such, and each one of them has many known enemies. Therefore, it should be evident that biological control does work!
What Can Be Done To Ensure Natural Control?
The most effective thing you can do to ensure natural insect control is reduce or eliminate the use of chemical insecticides whenever possible. Unfortunately, most insecticides do not selectively kill pest insects and leave beneficial insects to do their work. They kill all species of insects. Once this happens in a garden or field, several things occur which tilt the natural balance in favor of the pest insect. First of all, most beneficial insects which do survive a chemical application will migrate to a more desirable environment since they can usually find food or hosts anywhere. With the destruction and migration of beneficial insects, the surviving pests, who must remain on the plant for survival, begin to build their numbers rapidly. The key word is 'surviving'. The pests which survived were obviously immune to that dose of insecticide, so that the next application will have to be stronger. The next application will also have survivors, and so on, until the pest population is completely immune to the insecticide and free to grow to enormous proportions. Meanwhile the intolerable environment created by continued chemical applications will keep beneficial insects from re-entering the area. Cotton farmers have known for years that once-they begin spraying for worms, they have to continue to spray in order to prevent heavy crop damage. So what is the answer? The most effective and economical, biological control technique proven to date is the periodic releasing of known beneficial insects into a garden or field where pest insects can damage plants or crops. By releasing new beneficial insects, the farmer or gardener reinforces the native beneficial insects and allows a more rapid reduction of harmful pest populations. It is important to remember that as the pest populations go down, the beneficial population adjusts downward also. Thus periodic release of beneficial insects is necessary to ensure that migratory pests cannot come in to temporarily upset the natural balance. Although the natural balance would be restored eventually, the time elapsed could allow the pests to do considerable damage.
What About Special Situations?
In some areas a particular pest may enter where none or very few of its natural enemies are present. This situation is becoming more common today with the mobility of our society, particularly to and from foreign lands. Although precautions are taken at borders, occasionally an exotic pest will slip by and enter an area where its natural enemies do not exist. During the time entomologists are searching in the native country for its natural enemies, this particular pest is multiplying unchecked. In these cases there is little to do other than to apply insecticides. But all is not lost! By carefully limiting the application of insecticides to the time that the pest population builds to destructive levels, and by reintroducing beneficial insects artificially shortly thereafter, effective and less costly control can be maintained. A case in point is the Cotton Boll Weevil. Migrating from Mexico into the southern part of the United States, the Boll Weevil has been a persistent problem in the cotton fields. By carefully applying an insecticide in the early season, entomologists can eliminate early Boll Weevil damage. Afterwards worm control can be maintained for several weeks by introducing the Trichogramma Parasite Wasp into the fields. While the tiny wasp is stinging Bollworms and other worm eggs, other beneficial populations build naturally. By periodically releasing the Trichogramma, effective control can be maintained without any chemical applications until the next generation of Boll Weevils begins to emerge late in the season. Since cotton at this stage is in a more vulnerable state, periodic spraying is usually necessary for the remainder of the season. This strategy has helped farmers reduce their insect control costs by as much as 50%. This same strategy can be applied successfully in similar situations in gardens, trees, lawns, or other crops.
Trichogramma are among the smallest of insects, having a wingspread of about 1/50th of an inch. Despite its size, it is an efficient destroyer of eggs of many moth and butterflies which are the leaf-eaters in the larval stage. These parasitic insects disperse readily in their search for over 200 species of eggs to parasitize. The Trichogramma seeks out eggs, but does not feed on or harm vegetation. It is effective tool because it kills its host before the plant can be damaged.
They can be used in a variety of crops as well as in horticultural and ornamental plants. Trichogramma are used extensively in a variety of crops including cotton, corn, tomatoes, avocados, walnuts, pecans, apples, alfalfa, etc. The cost is so low that it is feasible to purchase them for massive releases.
Life cycle of Trichogramma
Minimum order of 5 squares = 25,000 plus Trichogramma
Agricultural requirements vary greatly.
We will furnish more information and price quotes upon request.
Trichogramma are shipped on squares of black paper with about 5,000 plus eggs glued to one-1 inch square. The Trichogramma are developed inside these eggs and should emerge on or near the date marked on the package. It is best to release them as you see them emerging. Place them in the crotch of trees, or inside the leaves of the plant. Releases should begin early when moths are first present and on a weekly basis thereafter.