How to control whiteflies? An introduction to practical control methods
The whitefly is a worldwide pest, also known as the small white moth. It occurs everywhere in China and has a wide host range. Cucumbers, kidney beans, eggplants, tomatoes, peppers, winter melons, beans, lettuce, as well as Chinese cabbage, celery, scallions, daphne flowers and others can all be damaged by it. It can also damage flowers, fruit trees, medicinal herbs, forage grasses, tobacco and other plants, affecting 653 species in 112 families. Let us take a look below at the control methods for whiteflies!
Living habits of the whitefly
In greenhouses in the north, the whitefly produces more than 10 generations a year, and cannot overwinter outdoors in winter; south of central China, it overwinters as eggs in open fields. After adults emerge, they can mate and lay eggs within 1-3 days, with an average of 142.5 eggs per female. They can also reproduce by parthenogenesis, with the offspring being male. Adults tend to prefer tender growth and lay eggs on the young leaves at the top of the plant. The eggs insert their egg stalks into the leaf tissue through the stomata, maintaining water balance with the host plant, and are extremely difficult to dislodge. After hatching, the nymphs walk short distances on the underside of the leaves within 3 days; once their mouthparts are inserted into the leaf tissue, they begin a sedentary life and lose the ability to crawl. The suitable temperature for whitefly reproduction is 18-21°C. In spring, they move into open fields along with transplanted seedlings or through greenhouse ventilation.
Damage characteristics of the whitefly
The whitefly damages fruit trees such as grapes, apples and persimmons, and also damages many vegetables such as tomatoes and lettuce, as well as forest tree species such as Paulownia. It is an important pest of courtyard grapes, flowers, vegetables and greening trees, and is especially abundant and severe on grapes and Paulownia. Adults and nymphs suck plant sap, causing damaged leaves to lose green color, turn yellow, wilt, and even die along with the entire plant. In addition, because of its strong reproductive capacity, fast reproduction speed, huge population size, and clustered feeding, it secretes large amounts of honeydew, seriously contaminating leaves and fruits, often causing outbreaks of sooty mold and making vegetables lose their commercial value. Besides seriously damaging Solanaceous crops such as tomatoes, green peppers, eggplants and potatoes, it is also a pest that seriously damages cucumbers and kidney beans.
Control methods for whiteflies
1. Whiteflies can be controlled by spraying pesticides. The pesticides used include 600-800 times dilutions of Jishijing, Jijianshi 1+1, acetamiprid, 1.3% (matrine), thiamethoxam, nitenpyram, fenpropathrin-malathion emulsifiable concentrate, cypermethrin-zinc emulsifiable concentrate, fenpropathrin, cyhalothrin or Tianshiwang, etc.
2. In greenhouses, aphid parasitoid wasps can be introduced, and whitefly adults have a strong tendency to be attracted to yellow. Yellow boards can be used to trap adults and coated with insect-sticking glue to kill the adults, but they cannot kill the eggs, so recurrence is easy.