Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Bean flower thrips (342)

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  • Widespread distribution. On food legumes, e.g., cowpea, French bean. Probably, minor pest in Pacific islands.
  • Infests the flowers. Pods twist and deform, and show brown feeding marks. Large numbers cause poor pod set, stunting, wilts. Not known to spread virus.
  • Nymphs yellow, later orange-red. Adults greyish-brown with striped abdomen.
  • Adults and nymphs spread on air currents.
  • Cultural control: crop rotation with non-legume crops; avoid planting next to infested crops; intercrop with non-hosts, e.g., capsicum between yard-long beans; weed; in small plantings, hose plants with jets of water to remove thrips; after harvest, destroy trash. 
  • Chemical control: pesticides not recommended; synthetic pyrethroids or malathion will kill natural enemies; also, difficult to reach inside flowers. If necessary, try botanical sprays (derris, chilli, garlic, neem), or horticultural oil, white oil, or soap solution (see Fact Sheet no. 56).  
Common Name

Bean flower thrips. It is also known as the Oriental bean thrips, Asian bean thrips.

Scientific Name

Megalurothrips usitatus; previously known as Taeniothrips nigricornis

AUTHOR Grahame Jackson
1Information from Swaine G (1971) Agricultural Zoology in Fiji. Her Majesty's Stationery Office. London; and CABI (2019) Megalurothrips usitatus (bean flower thrips) Crop Protection Compendium. (; and from Bean flower thrips (Megalurothrips usitatus) Plantwise Knowledge Bank. ( Photo 1 Desley Tree (2010) Oriental bean flower thrips, Asian bean thrips (Megalurothrips usitatus): PaDIL - ( Photo 2. Ko Ko Maung,

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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