Sugarbeet Leaf Miner Reference Page

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Sugarbeet Leaf Miner Reference Page

Spinach leafminer Pegomya hyoscyami ID photos: fact page (pdf):

Pest description and crop damage Legless maggots, ¹⁄2 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.

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

Management—biological control

Larvae often are highly parasitized.

Management—chemical control

1. aldicarb (Temik 15G, Temik 15G Lock’n Load) 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.

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 before planting.

2. azadiractin—

3. chlorpyrifos (Lorsban 75WG, and others at 0.5 lb ai/a broadcast postemergence. PHI 30 days. Do not allow livestock to graze in treated areas or harvest treated beet tops as feed for meat or dairy animals within 30 days after last treatment. Do not apply more than 4 lb ai/a or make more than four applications per season.

4. chlorpyrifos (Lorsban 75WG and others at 0.335 lb ai/a band postemergence. Apply as 5 to 7 inch band, and lightly incorporate mechanically or with irrigation.

5. diazinon (Diazinon 4E, Diazinon 50WP, Diazinon 500-AG, Diazinon AG 500, Diazinon AG600 WBC and others at 0.375 to 0.5 lb ai/a. PHI 14 days. REI 24 hr. Do not apply more than five times per season. Tops may be fed to beef and dairy animals.

6. horticultural oil (Concern Spray Oil, Ultra-Fine Oil, Biocover)—See label for rates. PHI 0 days.

7. insecticidal soap (M-Pede)—See label for rates. PHI 0 days. Apply in combination with other labeled insecticides. Wet spray must contact leafminer to be effective: no residual control after spray dries. Do not apply more than three times sequentially over a 2 week period.

8. paraffinic oil (Stylet Oil, Sunspray 6E Western) at 3 to 6 quarts product in 100 gal water/a (Stylet Oil); 2 gal product in 100 gal water/a (Sunspray 6E Western).

9. phorate (Phorate 20G, Thimet 20G) at 0.9 oz ai per 1,000 row ft at planting. PHI 30 days. Do not place granules in direct contact with seed. Drill to side of seed or band over seed. Do not feed sugar beet tops or silage to dairy cattle. No more than one application per cropping season.

10. pyrethrins and silicon dioxide (Diatect Multipurpose Insecticide II, Diatect V) at 1 to 6 lb product/a. Can be applied either as dust or wettable powder.

11. zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/a. PHI 50 days. Do not apply more than 0.15 lb ai/a per season (at planting + foliar applications). Apply with ground or air equipment using sufficient water to obtain full coverage of foliage.

Leaf Miner Information from the U of I

PNW Insect Management Handbook

Updated June 16, 2008-jn