Silverleaf Whitefly - Anatomy and Life Cycle

Anatomy and Life Cycle

During the adult stages of the silverleaf whitefly, the body expands up to 0.8mm in length and has a snow-white color, which is attributed by the secretion of wax across its wings and body. During feeding or resting stages the whitefly adult covers its body over with its wings. When depositing eggs, the females will lay 50 to 400 eggs ranging from 0.10mm-0.25mm on the under part of leaves. Female whiteflies are diploid and emerge from fertilized eggs whereas male whiteflies are haploid and emerge from unfertilized eggs. Eggs are laid in groups, being small in size with dimensions of 0.2 mm wide and .1mm in height. Eggs are initially whitish in color and change to a brown color towards the time of hatching within 5 to 7 days. After the egg stage, the whitefly hatchling develops through four instar stages.

In the first instar, commonly called the crawler, the nymph is 0.3mm in size and grows to be 0.6 mm till the fourth instar stage. During the first instar stage the body is greenish in color and flat in body structure. The mobile whitefly nymphs walks to find a suitable area on the leaf with adequate nutrients and molts into four other instar or nymphal stages over the span of 40–50 days until it reaches adulthood. During molting,the flies shed silver skins, which are left on the leaves. During the instar phases, the whitefly maintains an opaque white appearance and does not move from the feeding site the crawler originally chooses. At the feeding site the nymphs use parts of their mouth to stab into the plant and consume the plant’s juices. The stage following the nymph stages is the pupal stage where the eyes become a deep red color, body color is yellow and the body structure thickening in size. After development is completed, adult whiteflies are approximately four times the size of its egg with light yellow bodies and white wings.