Greenhouse whitefly is the main pest in the cultivation and production of vegetables in the protected areas of northern China, most of the greenhouse whitefly are greenhouse whitefly, which occurs seriously, not only directly harming vegetables, but also spreading tomato virus disease and other diseases. Lily aphid wasps are the main natural enemies of greenhouse whitefly, and experiments have proved that the use of aphid wasps to control greenhouse whiteflies is currently a more effective biological control measure.
How to release the best results
1. Prepare before release
Hanging yellow plate: Generally hanging at the standard of 20 pieces per acre, the purpose is to monitor the density of whitefly mouths.
Insect net: Install 60 mesh insect nets in the air vents and air windows of the greenhouse to prevent the invasion of small pests such as whiteflies and aphids. It should be noted that the temperature in the shed will increase after the installation of the insect net, and the air release time can be appropriately advanced or extended, and the width of the insect net can also be appropriately increased to increase the ventilation area.
Cultivate disease-free and insect-free seedlings, do not bring pests into the greenhouse, and pay attention to disease prevention at the seedling stage.
2, How to use
Release timing: When whitefly or crops have been seen in the greenhouse for a week, the release of aphid wasps begins. Do not wait for the number of whiteflies to be large before putting it, otherwise the effect is not good and the cost is high.
Release Method: Hang the bee card directly on the upper middle branch of the plant when used. The wasps automatically look for whiteflies and parasitize nymphs of whiteflies.
Release amount: 10 small cards (2000 heads) are released per acre at a time, and released every 7-10 days.
For overwintering crops, they are generally released 1-2 times before winter and 2-3 times after winter (early March). It is released 3-5 times throughout the growing season.
It is generally a spring and autumn crop. In spring, because the number of whitefly is small, it can be released 1-2 times. Whitefly are abundant in autumn and need to be released 2-3 times.
These issues require attention
1. The aphid wasp is small in size and has limited flight ability, and the bee card should be hung evenly in the field.
2, the release time should be early, in the early stage of pest occurrence, or even after colonization without seeing pests, release aphid wasps to ensure good control results. When pests occur in large quantities or in large quantities, it is not recommended to use directly and should be used at an appropriate time after the base of the source of the pest is depressed.
3. Prevent a large number of external insect sources from entering the shed. On the one hand, when planting, try to purchase clean seedlings; on the other hand, it is necessary to ensure the tightness of the shed and install insect-proof nets at the vents.
4, the appropriate temperature of the aphid wasp 10 °C -30 °C, the appropriate humidity of 60%-70%, the use of drip irrigation or submembrane dark irrigation, control the humidity in the shed, try to meet the conditions for the growth and development of the aphid wasp through management measures, reduce the impact of extreme temperature and humidity, promote the aphid wasp spawning to establish a population, thereby indirectly increasing the effectiveness of prevention.
5. After releasing the natural enemy, the insecticide is prohibited to avoid the killing of the natural enemy.
The above are a few points about releasing lice and wasps to control greenhouse whitefed, hoping to help farmer friends who are plagued by whiteflies.