Pacific Pests, Pathogens and Weeds

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Summary

• Widespread distribution. On mango, other fruit trees, ornamentals, and weeds. Probably important, but several webworms on mango.
• Larvae web together flowers, young fruits and leaves; leaves rolled and larvae feed from inside.
• Eggs on undersides of leaves; larvae yellowish green, with heads and first two pairs of legs black. Adults pale brown with dark markings, up to 20 mm long.
• Natural enemies: not recorded in Pacific islands (but assumed present).
• Cutural control: prune trees giving sprays better access.
• Chemical control: use Bt (Bacillus thuringiensis): ensure good coverage of shoots and flowers; treat when larvae small, and when webbing first seen. Avoid pyrethroids and organophosphates: they will kill natural enemies.