Spiny Cotton Bollworm
Earias insulana
moderate risk
insect
Overview
A significant cotton pest throughout the Middle East, North Africa, and South Asia, the Spiny Bollworm attacks cotton shoots, flowers, and bolls. It is particularly important in the Nile Valley and Egyptian cotton production, where it is considered a primary pest alongside the related Egyptian Bollworm.
Adults are small green-and-white moths 16–20 mm wingspan with a distinctive metallic green patch on the forewing. Larvae are 15–20 mm with characteristic fleshy spiny tubercles on each body segment — the source of the 'spiny' common name.
Prevention Strategies
- •Synchronise planting dates to concentrate and shorten crop's vulnerable period
- •Destroy crop residues immediately after harvest
- •Pheromone monitoring for adult flight timing
- •Avoid late-season nitrogen application that promotes vegetative growth attractive to ovipositing females
Control Methods
- •Trichogramma egg parasitoid releases (area-wide IPM program in Egypt)
- •Nuclear Polyhedrosis Virus (NPV) biopesticide specific to Earias larvae
- •Spinosad or emamectin benzoate sprays at egg hatch
- •Neem-based biopesticides as part of IPM rotation
- •Trap crops (okra rows at field margin to concentrate adults for spot treatment)
Interesting Facts
- •The Nile Valley SIT (sterile insect technique) program for cotton bollworms is one of the longest-running IPM programs in Africa
- •Spiny tubercles on the larva may deter some generalist predators
- •Egyptian Extra Long Staple cotton (ELS) — one of the world's most valuable natural fibres — requires intensive bollworm management to maintain quality