Cotton Whitefly (Silverleaf Whitefly)
Bemisia tabaci
high risk
insect
Overview
A tiny but catastrophically damaging pest of cotton, vegetables, and ornamentals across tropical and subtropical regions. Known primarily for vectoring over 200 plant viruses, most notably the begomoviruses (Tomato Yellow Leaf Curl Virus) that destroy entire tomato crops. One of the top 10 agricultural pests globally.
Adults are 1.0–1.5 mm with white waxy powdery wings, yellowish body. Nymphs are translucent flat scales on the underside of leaves, barely 0.3 mm. Puparia are white oval cases on leaf undersides.
Prevention Strategies
- •Use virus-resistant tomato varieties where available
- •Install 50-mesh insect-proof screens on greenhouse vents
- •Yellow sticky trap monitoring and mass trapping
- •Reflective mulches on soil to disorient adult flight
- •Avoid growing tomato and cotton in adjacent fields
Control Methods
- •Neonicotinoids (imidacloprid) as soil drench or seed treatment
- •Spiromesifen, pyriproxyfen (insect growth regulator) for nymphs
- •Biological control: Encarsia formosa parasitoid wasp (in greenhouses)
- •Insecticidal soaps and neem oil for organic management
- •Rotate to non-host crops to break population cycle
Interesting Facts
- •Bemisia tabaci is actually a species complex of over 40 distinct cryptic species morphologically indistinguishable
- •The Q-biotype developed resistance to all major insecticide classes within 5 years of widespread use
- •TYLCV, the virus it transmits, can destroy 100% of a tomato crop with no effective curative treatment
- •First appeared in Israel in the 1960s and spread to Mediterranean and North Africa by the 1980s