Whitefly is a common plant pest that mainly parasitizes on the surface or axils of leaves and sucks plant sap. The harm of this pest is mainly reflected in the following aspects:

1. Impact on plant growth and development: The ingestion of whitefly can lead to nutrient loss in the plant body, yellowing of leaves, loss of luster, and even death. In severe cases, it can hinder plant growth and reduce yield.

2. Spread of viral diseases: White whitefly is a common vector insect of viral diseases. It absorbs the juice of plants infected with the virus and then carries the virus to other plants, spreading the virus disease and causing plant death.

3. Polluted agricultural products: White planthoppers absorb plant sap while also excreting a large amount of honey dew and feces, seriously polluting agricultural products, affecting their quality and market prices.

Therefore, early detection of the harm of whitefly and effective prevention and control measures are of great significance for protecting plant growth and yield, and ensuring the quality of agricultural products.