Latest Corn Borer Control Technique: How to Use Trichogramma Wasps?

There are many species of Trichogramma wasps in nature. The Trichogramma species currently used to control the corn borer is Trichogramma dendrolimi. Generally, at the beginning of the adult corn borer's egg-laying period, Trichogramma wasps are artificially released into the field so that they lay their eggs inside the corn borer eggs, preventing the eggs from hatching into larvae, thereby achieving the goal of controlling the corn borer. Now let's take a look at how to use Trichogramma wasps to control the corn borer!

Release Timing

For Trichogramma control of the corn borer, wasps are released twice. The first release is at the beginning of the corn borer's egg-laying period, generally when the pupation rate of the overwintering generation of corn borers reaches 20% or when the egg mass rate per 100 corn plants in the field is 1 to 1.5 (fish-scale-like egg masses deposited on corn leaves). Then wait 10 days for the first release, and release the second time after an interval of 5 to 7 days. Each release is 10000 wasps.

Release Method

Using Trichogramma wasps to control the corn borer is one of the biological control methods for the corn borer. When using this technique, the plots must be contiguous. Release should begin at the early stage of corn borer egg-laying. The total number of wasps released per mu is 20000, with 10000 per mu for the first release and 10000 per mu for the second release.

How to Attach the Wasp Cards

Separate the wasp cards evenly (generally each wasp card contains about 70 tussah silkworm eggs, and each tussah silkworm egg can produce 70 to 80 Trichogramma wasps; generally 2 wasp cards are attached per mu). Fix them in the middle of the underside of the middle leaves of the corn plant in a shaded spot. The method is to select a middle leaf of a corn plant, roll the leaf downward into a tube shape, and then fasten it inside the tube with a toothpick or needle and thread.

Setting Release Points

Set 2 release points per mu. Counting from the edge row of the release field, the 15th row is the first release row. Walk 15 steps inward along the first release row to reach the first release point, then walk 30 more steps forward along the row to reach the second release point. Walk 30 steps inward along the second release row to reach the second release point. Follow the above method and so on.

Precautions

1. When releasing wasps, choose a sunny morning and avoid noon or windy weather. If there is heavy rain, release the wasps after the rain. Light rain does not matter.

2. After receiving the wasp cards, immediately attach them to the corn leaves, no later than 1.5 days.

3. The hatching time of the corn borer must coincide with the emergence time of the Trichogramma wasps.

4. Trichogramma wasp cards are distributed free of charge.

5. Generally, Trichogramma wasp cards should be attached by a professional wasp release team organized uniformly by the township-level department. If there are violations locally, you can complain to the local government.