Silverleaf whitefly (Bemisia tabaci) is a major pest of eggplants and many other crops worldwide. It belongs to the family Aleyrodidae and is one of the most destructive pests due to its ability to transmit plant viruses, cause direct damage to plants, and produce large amounts of honeydew, which attracts ants and promotes the growth of sooty mold.
Management of Silverleaf Whitefly in Eggplant
The life cycle of Silverleaf Whitefly
- The life cycle of the Silverleaf whitefly consists of four main stages: egg, nymph, pupa, and adult. The duration of each stage varies depending on temperature and other environmental factors.
- The life cycle begins when adult females lay small, oval-shaped eggs on the undersides of leaves. The eggs are translucent and usually hatch within five to seven days.
- After hatching, the first instar nymphs emerge and feed on the plant sap. The nymphs have legs and antennae and can move around the plant to find suitable feeding sites. After the first molt, the nymphs lose their legs and antennae and become immobile, remaining attached to the leaf surface for the rest of their development.
- Over the next three instars, the nymphs feed and grow, gradually changing from pale yellow to yellow-green. Once the fourth instar is complete, the nymphs enter the pupal stage, transforming into adults.
- Adults emerge from the pupal stage and typically begin to mate within 10-20 hours. Male adults usually emerge first in the morning, followed by females. The timing of emergence is temperature-dependent, with earlier emergence at higher temperatures.
Identification of Silverleaf Whitefly in Eggplant field
Adults are very small, measuring only about 0.06 inches (1.5 mm) in length, and have a yellowish body with four white wings. The wings are held at a slight angle, forming a roof-like structure over the body, and do not touch or overlap over the back, leaving a small space between them. The nymphs of silverleaf whiteflies can also be identified on the undersides of leaves. They are small and oval-shaped, with a flat, disc-like appearance.
Damage symptoms of Silverleaf Whitefly in Eggplant field
- One of the most noticeable symptoms is the presence of large numbers of tiny white insects on the undersides of leaves. These insects feed on the plant’s sap, leading to stunted growth, wilting, and yellowing of the leaves.
- As the whiteflies feed, they excrete large amounts of sticky honeydew, which can cover the leaves and fruit of the eggplant.
- This honeydew attracts ants and other insects and can also promote the growth of black sooty mold, further reducing the plant’s ability to photosynthesize and produce healthy fruit.
- The black mold can also make the fruit unattractive and difficult to market.