What precautions should be taken when applying pesticides to orchids?

Temperature: The active ingredients of biological pesticides are composed of protein crystals and living spores. It is essential to keep the temperature ideally above 20°C. Once spraying is done below this temperature, the reproduction rate of the spores inside the pest's body will be very slow, and the protein crystals will also struggle to play their role, often showing no control effect after spraying. According to experiments, spraying biological pesticides at 25-30°C gives a insecticidal effect 1-2 times higher than spraying at 10-15°C.
Environment: The higher the humidity, the more pronounced the efficacy of biological pesticides, especially powdered biological pesticide formulations. It is best to spray bacterial powder in the morning and evening when there is dew, so that the agent can adhere well to theorchidstems and leaves, allowing the spores to multiply quickly.
Sunlight: The ultraviolet rays in sunlight have a lethal effect on spores. Scientific experiments show that under direct exposure to strong sunlight for just 30 minutes, the spore mortality rate reaches 50%. After 1 hour of exposure, the spore mortality rate is as high as 80%, and furthermore, ultraviolet radiation can also deform the parasporal crystals and reduce their efficacy. Therefore, choosing to apply biological pesticides after 16:00 or on cloudy days will give better efficacy.
Rain: Heavy rain will wash away the sprayed biological pesticides, causing the spores to lose their killing power. However, if light rain occurs for five or six hours after spraying, the efficacy will not only not decrease but will actually increase. This is because light rain is very favorable for the reproduction of spores, which can kill more pests.
Watch the wind: Applying bacterial pesticides on windy days causes great waste, especially powder formulations, which drift away even more. At the same time, windy days are also unfavorable for spore germination. Therefore, bacterial pesticides should be applied on windless or breezy days.