Cereal Leaf Beetle Reference Page

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Cereal Leaf Beetle Reference Page

Coleoptera (Beetles): Crysomelidae (Leaf Beetles) Species: Oulema melanopus

Key Hosts: Oats, Barley, Wheat, other grasses

Pest description and crop damage Adults are small beetles about ¹⁄4 to ³⁄8 inch, with a metallic blue head and wing covers, red pronotum, and yellow-orange legs. Larvae are yellow to yellow-brown with a dark mass of slimy fecal material on their backs.

Both adults and larvae feed on leaves. Feeding causes a characteristic stripping of the leaves.

Sampling and thresholds Treat when there are three larvae or eggs per plant up to the boot stage. After boot, treat at one larva per flag leaf.

Management—biological control

These insects are controlled easily by introduced parasitoids.

Management—chemical control

1. carbaryl (Carbaryl 4L) at 1 quart/a. PHI zero days for foraging, 21 days for grain. Wheat only. No more than two applications after head emergence. Latex-based formulations of carbaryl, such as Sevin XLR Plus, are least hazardous to bees.

2. carbofuran (Furadan 4F) at 8 oz/a when insects appear. Apply before heading. Do not apply more than two times per growing season. Do not feed forage. Barley, oats, wheat.

3. endosulfan (Thiodan 3EC and Thionex 3EC) at 10.6 to 21.4 oz/a. Do not apply after heads begin to form. Apply when small larvae are found readily in field. For aerial applications, apply in 2 gal crop oil/a. Do not apply more than twice per season. Do not feed treated forage to livestock. Do not exceed maximum of 1 lb active ingredient (i.e., 1.33 quarts/acre) per year.

4. endosulfan (Thiodan 50WP, 50WSB, and Thionex 50W) at 1 lb/a. Do not apply after heads begin to form. Do not apply more than twice per season. Durum wheat and barley as foliar spray. Do not feed treated forage to livestock.

5. lambda-cyhalothrin (Warrior+Zeon and Warrior T+Zeon) at 2.56 to 3.84 oz/a. PHI 30 days. Wheat only. Do not apply more than 0.48 pint/a per season.

6. methomyl (Lannate LV) at 0.75 to 1.5 pints/a. Do not exceed 1.8 lb ai/a/crop. Do not make more than four applications per crop. PHI 7 days, 10 days for grazing.

7. methomyl (Lannate SP) at 0.25 to 0.5 lb/a. Do not exceed 1.8 lb ai/a/crop. Do not make more than four applications per crop. PHI 7 days, 10 days for grazing.

8. malathion (Malathion 5EC and 5) at 1 to 1.5 pints/a. Wheat, barley, oats, and rye. PHI 7 days.

9. malathion (Malathion 8 Aquamil) at 1.25 pints/a. PHI 7 days.

10. malathion (Malathion and Fyfanon ULV) at 4 to 8 fl oz/a. Barley, oats, and wheat. PHI 7 days.

11. spinosad (Success) at 2 to 6 fl oz/a. PHI 21 days; 14 days for grazing or straw. Do not apply more than 19 fl oz/a/year.

12. spinosad (Tracer) at 1 to 3 fl oz/a. PHI 21 days; 14 days for grazing or straw. Do not apply more than 9 fl oz/a/year.

13. zeta cypermethrin (Mustang) at 1.9 to 4.3 fl oz/a. Wheat only. PHI 14 days, also for forage and hay. Do not make applications less than 14 days apart. Do not apply more than 0.25 lb ai/a/year.