Onion-Leafminer

Includes

American serpentine leafminer (Liriomyza trifolii)

Pea leafminer (Liriomyza huidobrensis)

Pest description and crop damage Adults are small black to gray flies with yellow markings. The body is covered with long, stiff bristles. Larvae are a nearly translucent white or yellow and about 0.25 inch long when mature. Eggs are white, cylindrical, and laid singly or in small groups. Adult leafminers may stunt seedlings by attacking the cotyledons in seeds. Larvae mine between upper and lower leaf surfaces, creating winding, whitish tunnels that initially are narrow but then widen as the larvae grow. Excessive mining renders leaves unmarketable, reduces photosynthetic capacity, and provides easy access for disease organisms.

Management-chemical control: HOME USE

  • acetamiprid
  • azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
  • cyhalothrin
  • deltamethrin
  • gamma-cyhalothrin
  • lambda-cyhalothrin
  • malathion
  • permethrin
  • pyrethrins-Some formulations are OMRI-listed for organic use.
  • spinosad-Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

  • abamectin (Agri-mek 0.15) at 0.009 to 0.019 lb ai/a. PHI 30 days. REI 12 hr. Do not exceed 0.019 lb ai/a per season. Retreatment interval 7 days.
  • cyantraniliprole (Exirel) at 0.088 to 0.133 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 5 days. Rotate with other modes of action. Begin applications early for best results. Do not exceed 0.4 lb ai/a per season.
  • cyantraniliprole + abamectin (Minecto Pro) at 7 to 10 fl oz/a. PHI 30 days. Do not apply more than two times in a row. Retreatment interval 7 days. Do not apply more than 20 fl oz/a per season (0.18 lb ai/a of cyantraniliprole and 0.038 lb ai/a of abamectin).
  • cypermethrin (Holster) at 0.04 to 0.1 lb ai/a. PHI 7 days for dry bulb onion only. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.5 lb ai/a per season. Do not graze or feed crop residues to livestock. Wait 30 days to plant rotational crops.
  • cyromazine (Trigard) at 0.125 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not apply more than 6 applications per crop.
  • dinotefuran (Scorpion 35SG) at 0.135 to 0.18 lb ai/a foliar; 0.225 to 0.27 lb ai/a soil. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not apply more than 0.266 lb ai/a per crop.
  • gamma-cyhalothrin (Declare) at 0.0075 to 0.0125 lb ai/a. PHI 14 days. REI 24 hr. Retreatment interval 5 days. Do not exceed 0.12 lb ai/a per season. An oil or nonionic surfactant improves control.
  • lambda-cyhalothrin (Warrior II) at 0.015 to 0.025 lb ai/a. PHI 14 days. REI 24 hr. Do not exceed 0.24 lb ai/a per season. Retreatment interval 5 days. An oil or surfactant adjuvant improves control.
  • permethrin (Pounce 25W, Ambush 25W) at 0.1 to 0.3 lb ai/a. PHI 1 day. REI 12 hr. Do not exceed 2 lb ai/a per season. Do not feed culls or graze. Toxic to fish.
  • spinetoram (Radiant SC) at 0.0468 to 0.078 lb ai/a. PHI 1 day. Retreatment interval 4 days. Do not exceed 5 applications or 0.234 lb ai/a per season. Follow resistance management procedures on the label.
  • spinosad (Success) at 0.047 to 0.094 lb ai/a. PHI 1 day. REI 4 hr. Retreatment interval 4 days. Do not exceed 0.45 lb i/a per season. Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Adults only. Do not exceed 0.25 lb ai/a per season. Do not graze livestock or cut for feed.