Couplet 25

10/22/2010 3:25:03 AM


Puparium or larva near edge of leaf blade; bump in leaf.

Insect may be:

Puparium behind leaf sheath; golden-crown puparium, rounded at each end.

Insect may be:



Photos by: Johnny Saichuk

Photos by: Johnny Saichuk


  • Adults are metallic blue-green to gray flies with clear wings (1/4 inch long). They fly near the water and lay eggs on rice seedling leaves. Transparent or cream-colored larvae emerge in less than one week and feed between the layers of the rice leaf. Larvae become yellow to light green while feeding for one to two weeks before pupation. Adults emerge and live two to four months. The life cycle is completed in two weeks to one month.


  • Leafminers attack rice fields in early spring in the same vicinity year after year.
  • Infestations usually occur where water is deepest on the upper side of levees. Leafminers are not usually a problem in shallow water.
  • Leafminers are more severe in continuously flooded than in periodically flooded rice.
  • Larvae tunnel between the leaf layers (mining the interior), attacking and killing leaves closest to the water before moving up the plant, killing additional leaves and possibly the entire seedling.

What you should look for:

  • Walk through flooded rice fields and draw leaves between your thumb and forefinger.
  • Bumps in leaves indicate leafminer larvae or pupae.

How you can manage the rice leafminer:

  • Maintain water depth at 4-6 inches.
  • Lower the water level in fields so that rice leaves can stand up out of the water.
  • Treat if plant numbers are reduced to less than 15 per square foot.


  • Adults are small, gray flies of about 1/10-inch in length. Eggs are laid on near the margin of rice leaves. Larvae are small, white or yellowish maggots (1/4-inch long). The brown puparium is elongate and tapered at both ends.


  • SARM is an invasive insect pest of rice in the United States.
  • Because of damage to the rice plant whorl, SARM is called “whorl maggot”.
  • It is common to find more than one maggot in a single stem.
  • Rice injury tends to occur from emergence until tillering, especially in late planted fields.

What you should look for:

  • The maggot inures rice be causing large, elongated lesions on the margins of emerging leaves.
  • The maggots mine or rasp the leaf before it unfurls.
  • As the leaf expands, yellow damaged areas are visible.
  • Damaged leaves usually break off or are ragged in appearance.
  • The maggot continues to feed on the whorl tissue and enters the stem of developing plants.
  • Affected seedling plants are killed or plant growth is severely retarded.
  • Pupation occurs inside the affected stem, near the leaf collar.
  • Field damage is distributed in large patches either in the center or along the margins of the field.

How you can manage the SARM:

  • The only recommendation available at this time is to avoid late planting.



For more information, please see the Rice section of the Insect Pest Management Guide on the LSU AgCenter's Management Guides webpage.

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