Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Bean (cowpea) fly (291)

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  • Worldwide. Sub-tropics and tropics. On beans of many kinds - Vigna, Phaseolus, and weeds.
  • Eggs in seedling leaves hatch, and larvae tunnel to the midrib, then to the petiole and lower stem.
  • Plants wilt, are stunted, or may fail to yield.
  • Natural enemies: parasitoid wasps.
  • Cultural control: remove volunteers and weeds; avoid overlapping crops; hill-up 2-3 weeks after germination (damage stimulates roots) ; mulch to encourage root formation; tolerant varieties.
  • Chemical control: commercial growers – treat seed (e.g., imidacloprid); or spray plants (dimethoate).
Common Name

Bean fly

Scientific Name

Ophiomyia phaseoli; previously Melanagromyza phaseoli.

AUTHOR Grahame Jackson 
Information from CABI (2015) Ophiomyia phaseoli (bean fly). Crop Protection Compendium (; and from  DAF (2018) Bean fly. Business Queensland. Queensland Government. ( Photos 1&2 Shepard M et al. Insects and their natural enemies associated with vegetables and soybean in Southeast Asia, Photo 3 Shane McEvey, Australian Museum (Phyiomyia sp., Townsville, Queensland).

Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community. 

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