Spray repeatedly every two to three days to catch emerging adults and kill them before they lay more eggs. Sprays usually destroy only the flying adults, not the eggs. Pesticide resistance is becoming a big problem and many chemicals are no longer effective against whitefly so you should try various brands. This lays eggs in whitefly scales, parasitising and killing them. Introduce the wasp as soon as you spot the whitefly, possibly as early as May or June.
Most companies send the wasp in three batches at timed intervals.
Make sure you follow the instructions sent with your order. Ask our experts for their advice or read their comments about controlling pests and diseases . Your technical gardening terms explained.