Worldwide distribution. In the tropics, sub-tropics and temperate countries. On members of the cabbage family, Chinese cabbage in particular. An important pest.
Adults, 2mm long, occur in large numbers, eating tiny holes in the leaves, making them unmarketable.
Eggs are laid in the soil and the larvae feed on roots.
Biosecurity: Limited distribution in Pacific islands.
Cultural control: avoid planting near or downwind from infested crops; use fertilizer, manures or composts to accelerate growth; monitor for beetles (cardboard covered in grease moved quickly along the row); collect and burn debris after harvest; crop rotation.
Chemical control: PDPs: neem, pyrethrum, or derris; or synthetic pyrethroids, but they are likely to kill natural enemies.