The Chilli Whitefly, Bemisia tabaci, belonging to the Family Aleyrodidae of the Order Hemiptera, is a notorious pest that causes significant yield losses and reduces the quality of crops worldwide. It is also known as Silverleaf Whitefly or Sweet Potato Whitefly. The chilli whitefly is a sap-sucking insect that feeds on the phloem sap of the chilli plant, causing it to weaken, wilt, and eventually die.
The chilli whitefly is known to transmit several viruses, like, Tomato yellow leaf curl virus and Pepper golden mosaic virus, that can cause severe damage to chilli crops. These viruses can lead to stunted growth, yellowing of leaves, and reduced yields. To effectively manage this pest, it is essential to understand its life cycle, its preferred habitats, and the best methods for controlling it. This article will provide an overview and discussion of the Chilli Whitefly Pest in Chilli crops, including its symptoms, identification techniques, and control.
Whitefly Pest Management in Chilli
Life Cycle of Chilli Whitefly Pest in Chilli Crop
The life cycle of the Chilli Whitefly pest has four stages. They are egg, nymph, pupa, and adult. The life cycle begins when the female chilli whitefly lays eggs on the underside of the leaves. Depending on temperature and humidity, they are usually laid in circular or irregular patterns and take around 5-10 days to hatch.
After hatching, the eggs develop into nymphs. They feed on the plant sap by inserting their mouthparts into the leaf tissue. The nymphs go through four instars, shedding their skin between each instar. The duration of the nymphal stage varies between 7-14 days, depending on temperature and humidity. After the fourth instar, the nymphs moult into pupae, which are immobile and enclosed in a waxy, protective covering called a puparium.
The pupal stage lasts approximately 4-5 days before emerging as adult whiteflies. The adults are capable of flight and can disperse to other plants or even other fields. The adults mate soon after emergence, and the females begin laying eggs, starting the life cycle again. The entire life cycle of chilli whiteflies, from egg to adult, can take anywhere from 20-30 days.
Occurrence of Chilli Whitefly Pest in Chilli Crop
- Location of Chilli Whitefly Pest: This pest infests Chilli crops in India, Bangladesh, Nepal, Africa, Sri Lanka, China, Thailand, Malaysia, Vietnam, Indonesia, the United States, Mexico, Brazil, Colombia, Ecuador, the Philippines, New Zealand, and Australia.
- Host Range: The Chilli Whitefly pest infects crops like Chilli, Tomato, Brinjal, Cotton, Citrus, Poinsettia, Hibiscus, Cucumber, Squash, Pumpkin, and Sweet Potato.
Factors Favoring the Population Increase of Chilli Whitefly Pest in Chilli Crop
- Temperature – The pest prefers warm temperatures between 25°C to 30°C. In areas with warm temperatures, the pest can reproduce quickly.
- High Humidity – The pest can absorb moisture from the air, and high humidity levels provide the ideal conditions for the pest to thrive and reproduce.
- Low Light Intensity – The pest prefers low light intensity, and shaded areas are favourable for their survival and reproduction.
- Poor Plant Nutrition – Plants that are stressed or have poor nutrition are more susceptible.
- Lack of Natural Enemies – Pest populations can quickly multiply in areas with few natural enemies.
- Monoculture – The pest can quickly move from plant to plant and can lead to the build-up of pest populations.
Identification of Chilli Whitefly Pest in Chilli Crop
- Egg: The eggs are small, white or pale yellow, oval-shaped, and approximately 0.2mm long.
- Nymph: The nymphs are small, pale yellow, wingless, oval-shaped, and have a distinct, dark eye spot.
- Adult: The adults are small, white insects with four wings covered in powdery wax. The female adult is larger than the male and has longer wings.