1. Insect
  2. Agronomic Crops
  3. Sugar Beet Pests

Sugar beet-Leafminer

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Image related to Sugar beet-Leafminer
Spinach leafminer-beet leafminer
Pegomya hyoscyami Panzer
Egg(s) on host
© Ken Gray Insect Image Collection
Image related to Sugar beet-Leafminer
Spinach leafminer-beet leafminer
Pegomya hyoscyami Panzer
Molting
© Ken Gray Insect Image Collection
Image related to Sugar beet-Leafminer
Spinach leafminer-beet leafminer
Pegomya hyoscyami Panzer
Showing damage on leaves
© Ken Gray Insect Image Collection
Image related to Sugar beet-Leafminer
Spinach leafminer-beet leafminer
Pegomya hyoscyami Panzer
Immature
© Ken Gray Insect Image Collection

Beet leafminer (Pegomya betae)
Spinach leafminer (Pegomya hyoscyami)

Pest description and crop damage Legless maggots, 0.5 inch long when mature, feed between the upper and lower leaf surfaces, leaving irregular transparent windows, blotches, and winding tunnels. Historically a common pest that rarely reached economically damaging levels, it is now an increasingly important pest in some local areas. Damage is of more concern early in the season during stand establishment; older plants should be able to tolerate more leafminer damage.

Scouting and thresholds No formal economic thresholds exist for leafminer insecticide treatment decisions.

Management-biological control

Larvae often are highly parasitized. We do not yet know enough about arthropod natural enemies to suggest practical ways of manipulating and enhancing their effects other than avoiding any unnecessary insecticide applications.

Management-chemical control

  • aldicarb (AgLogic 15G, AgLogic 15GG) at 2.1 to 3 lb ai/A. PHI 90 days, 120 days if tops are fed to livestock. Do not use tops as food for humans. Do not make more than one at-planting and two postemergence applications per crop. Do not exceed a total of 4.95 lb ai/A per season. Immediately deep-disk any spills at row ends or elsewhere to ensure the granules are covered with a layer of soil. Washington only.
    • At planting (or within 1 week prior)-Drill granules 1 to 3 inches below seedline. Granules can be placed into the seed furrow if rate does not exceed 1.05 lb ai/A.
    • Postemergence-Apply granules to both sides of plant row and immediately work into the soil or cover with soil, or, for furrow irrigation, side-dress granules 4 to 8 inches to water furrow side of plant row and at furrow depth. Irrigate soon after application. Apply within 60 days after planting. Do not make any postemergence applications if 4.05 to 4.95 lb ai/A was applied at planting or within 1 week prior to planting.
  • azadirachtin-Some formulations are OMRI-listed for organic use.
    • (Aza-Direct) at 0.0123 to 0.024 lb ai/A and up to 0.0432 lb ai/A under extremely heavy infestation.
    • (Debug Trés) at 0.0375 to 0.1054 lb ai/A
    • (Ecozin Plus) at 0.012 to 0.023 lb ai/A. Spray when pests first appear and repeat after 7-10 days.
  • clothianidin (NipsIt INSIDE, Lumisure)-Application only by commercial seed treaters; no on-farm seed-treatment application.
  • clothianidin/Bacillus firmus I-1582 (Poncho/Votivo)-Application only by commercial seed treaters; no on-farm seed-treatment application.
  • clothianidin/beta-cyfluthrin (Poncho Beta)-Application only by commercial seed treaters; no on-farm seed-treatment application.
  • mineral oil (470 Supreme Spray Oil, BioCover, JMS Stylet Oil, SunSpray, and others)-See label for rates. Some formulations are OMRI-listed for organic use.
  • phorate (Thimet 20-G EZ Load, Thimet 20-G Lock'N Load, Thimet 20-G Smartbox)-Apply at planting 0.68 to 0.9 oz ai/1,000 row ft. PHI 30 days. Do not feed tops or silage to dairy cattle. Do not place granules in direct contact with seed. Drill to side of seed or band over seed. No more than one application per cropping season.
  • potassium salts of fatty acids (M-Pede)-See label for rates. Apply only in tank mix with labeled companion insecticide; see label about tank mixing. PHI 0 days.
  • pyrethrins (Lynx EC 1.4, Lynx EC 5.0, PyGanic EC 1.4, Tersus)-See label for rates. REI 12 hr. PHI 0 days. Some formulations are OMRI-listed for organic use.
  • pyrethrins and piperonyl butoxide (Pyronyl Crop Spray and Pyrenone)-See label for rates.
  • spinosad
    • (Blackhawk) at 0.051 to 0.079 lb ai/A. Do not apply fewer than 7 days apart. Do not apply more than 0.33 lb ai per crop. PHI 3 days.
    • (Entrust, Entrust SC) at 0.07 to 0.16 lb ai/A. Do not apply fewer than 7 days apart. Do not apply more than four times per crop or apply more than 0.33 lb ai/A per crop. PHI 3 days. OMRI-listed for organic use.
    • (Radiant SC) at 0.05 to 0.0625 lb ai/A. For suppression only. Do not apply more than 0.25 lb ai/A per crop. PHI 7 days.
    • (Success) at 0.025 to 0.05 lb ai/A. Do not apply more than four times per crop or apply more than 0.45 lb ai/A per crop. PHI 3 days. Use of a penetrating surfactant oil is critical for optimal control of leafminers.
  • thiamethoxam (Cruiser 5FS)-Application only by commercial seed treaters; no on-farm seed-treatment application.
  • zeta-cypermethrin-
    • (Mustang) at 0.028 to 0.05 lb ai/A. PHI 50 days. Adult control only. Do not apply more than 0.15 lb ai/A per season (at planting/foliar applications). Apply with ground or air equipment using enough water to fully cover foliage.
    • (Mustang Maxx) at 0.014 to 0.025 lb ai/A. PHI 50 days for tops or roots. Adult control only. Do not apply more than 0.075 lb ai/A per season. REI 12 hr. Apply by air or ground using minimum of 2 gal per acre by air and 10 gal per acre by ground.