Correct use of biological pesticides

Biopesticides are known as green pesticides due to their advantages of being non-toxic, non-polluting to the environment, and insusceptibility to diseases and insect pests, which have broad prospects for development. At present, many places in our province have begun to accept or use this kind of pesticides, but we must pay attention to the following issues in use. The first is temperature. The suitable temperature for spraying biological pesticides is above 20°C. Because the active ingredients of these pesticides are protein crystals and living spores, spores in the low-temperature propagation rate in insect pests are extremely slow, and protein crystals are not easily affected. According to experiments, the application of biopesticides at 25°C to 30°C is twice as effective as that at 10°C-15°C. The second is humidity. The use of biological pesticides, the higher the ambient humidity, the higher the efficacy, especially the application of powdered biological agents, can only be fully exerted under high humidity conditions. The reason is that the buds of bacteria are not able to withstand the dry environmental conditions. Therefore, it is advisable to spray the bacterial powder in the morning and evening when there is dew, in order to facilitate the bacteria to adhere to the stems and leaves, and to promote the propagation of spores, increasing the chance of contact with the pests. The third is sunshine. Ultraviolet rays in the sun have a killing effect on spores, direct sunlight for 30 minutes, spores can be about 50% of death, irradiation for 1 hour, the mortality rate is as high as 80%, and ultraviolet radiation on the protein crystals also have deformation and lowering effect. Therefore choose to use biological pesticides after 4 pm or on cloudy days. The fourth is rain. Moderate to heavy rain will flush out the bacterial liquid sprayed on the leaves, reducing the efficacy, but if the light rain after 5 hours after application, it will not only reduce the efficacy, but can improve control efficiency. Because of the beneficial effects of spores on light rain, pests can accelerate their death.