Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Cotton mealybug (373)

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  • Worldwide distribution. Recorded from Australia and Fiji. Over 200 hosts: cotton, okra, papaya, potato family, and weeds. Above and below ground.
  • Damage, direct: adults and nymphs suck sap. Leaves yellow, plants become stunted, flowers and fruits fall; indirect damage from dark mould growth over leaves from deposits of mealybug honeydew.
  • Eggs, laid into ovisac, develop into crawlers, then adults covered in powdery wax. Females with spots on top, and 18 waxy filaments at margins. Males mosquito-like but no mouths.
  • Spread by crawlers carried in wind, birds, clothing, machinery. Movement of nursery stock.
  • Natural enemies: ladybird beetles, and many wasp parasitoids.
  • Cultural control: (i) nursery - weed; check plants, (ii) field - remove volunteer plants and weeds; avoid overlapping crops; handpick or prune infested leaves; hot water to destroy ant nests (plants will tolerate up to 49°C); collect and burn debris after harvest.
  • Chemical control: use soap solution, horticultural or white oils (see Fact Sheet no. 56). Avoid synthetic pesticides; only use e.g., synthetic pyrethroids to kill ants.
Common Name

Cotton mealybug, Solenopsis mealybug

Scientific Name

Phenacoccus solenopsis. It is possible that different biotypes exist in the Americas compared to Asia.

AUTHOR Grahame Jackson & Mani Mua
Information from CABI (2018) Phenacoccus solenopsis (cotton mealybug). Crop Protection Compendium. (; and Scalenet. Phenacoccus solenopsis Tinsley 1898 (Pseudococcidae: Phenacoccus. (; and from Phenacoccus solenopsis Tinsley. Plant Pests of the Middle East. ( Photo 6 Buamas C (2010) Solenopsis mealybug (Phenacoccus solenopsis): PaDIL - (

Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland and the Secretariat of the Pacific Community.

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