Thrips

Common name

 

Scientific name

Stenchaetothrips biformis (Bagnall)

 

What it does

Feeding damage caused by thrips causes leaf curling and discoloration.

Why and where it occurs

Rice thrips are more serious pests during the dry season. It infests the rice plant during the seedling stage or 2 weeks after early sowing.

Periods of dry weather favor the development of the rice thrips. No standing water in the rice fields encourages damage.

These insects are present in all rice environments. In the tropics, the rice thrips becomes abundant in dry periods from July to September and January to March. In temperate areas, the insects migrate and hibernate on graminaceous weeds during the winter season.

The adult thrips are day-flying. They migrate during the day and look for newly planted rice fields and other hosts.

Eggs are laid in the slits of leaf blade tissue. The upper half of the egg is exposed.

Neonate larvae feed on the soft tissues of unopened young leaves.

How to identify

Check the plants for feeding damage:

  • Leaves damaged have silvery streaks or yellowish patches
  • Translucent epidermis becomes visible on damaged area
  • Leaves curled from the margin to the middle
  • Leaf tips wither off when severely infested
  • Unfilled grains at panicle stage

Rolled leaves are also symptoms of drought. To confirm rice thrips damage, check for the presense of thrip inside the curled leaves.

  • cream-colored eggs on leaf tissue with upper half of eggs exposed on leaf surface
  • yellow larvae and dark brown adults lacerate the plant tissues
  • leaf shows discoloration and rolling, and extensive removal of leaf tissues causes a translucent epidermis to remain

Click on images to enlarge

How to manage

  • Use resistant varieties
  • Flood to submerge the infested field for 2 days
  • Encourage biological control agents: predatory thrips, coccinellid beetles, anthocorid bugs, and staphylinid beetles

Learn more

View full fact sheet:
Thrips on IRRI Rice Knowledge Bank