Small grain-Cereal leaf beetle

Oulema melanopus

Pest description and crop damage Adults are small beetles about 0.25 to 0.375 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, which makes them look like dark, shiny, and round objects on the leaves.

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. The primary biocontrol agents (parasitoids) are two wasp species: Tetrastichus julis (a larval parasitoid) and Anaphes flavipes (an egg parasitoid).

Management-chemical control

Foliar spray

  • alpha-cypermethrin (Fastac EC) at 0.012 to 0.025 lb ai/A. PHI 14 days for grain, forage and hay. REI 12 hr. Retreatment interval 14 days. Do not exceed 0.075 lb ai/A per season. Wheat and triticale.
  • Beauveria bassiana GHA (Mycotrol ESO) at 0.5 to 2 pints/A. PHI 0 days. REI 4 hr. Do not apply more than 6 pints/A. OMRI-listed for organic use.
  • beta-cyfluthrin (Baythroid XL) at 0.008 to 0.014 lb ai/A. PHI 30 days, 3 days for grazing or foraging. REI 12 hr. Retreatment interval 3 days. Do not exceed 0.038 lb ai/A per season.
  • Chromobacterium subtsugae (Grandevo WDG) at 0.6 to 0.9 lb ai/A. PHI 0 days. REI 4 hr. OMRI-listed for organic use.
  • cyfluthrin (Tombstone) at 0.016 to 0.028 lb ai/A. PHI 30 days, 3 days for grazing or foraging. REI 12 hr. Retreatment interval 3 days. Do not exceed 0.076 lb ai/A per season of cyfluthrin alone, or the combined total of cyfluthrin plus beta-cyfluthrin. Wheat only.
  • diflubenzuron (Dimilin 2L) at 0.0625 lb ai/A. PHI for grain and straw 50 days; forage 3 days; hay 15 days. REI 12 hr. One treatment per season. Barley, oats, triticale, and wheat.
  • fenpropathrin (Danitol) at 0.2 lb ai/A. REI 24 hr. Do not exceed 0.2 lb ai/A per season. One treatment per season. Apply before the boot stage of growth. Barley only.
  • gamma-cyhalothrin (Declare) at 0.01 to 0.015 lb ai/A. PHI 30 days, 7 days for grazing or foraging. REI 24 hr. Do not exceed 0.03 lb ai/A per season.
  • lambda-cyhalothrin (Silencer, Warrior II) at 0.02 to 0.03 lb ai/A. PHI 30 days, 7 days for grazing or foraging. REI 24 hr. Do not exceed 0.06 lb ai/A per season.
  • lambda-cyhalothrin/chlorantraniliprole (Besiege) at 0.059 to 0.098 lb ai/A. PHI 30 days, 7 days for grazing or foraging. REI 24 hr. Retreatment interval 7 days. Do not exceed 0.06 lb ai lambda-cyhalothrin or 0.2 lb ai chlorantraniliprole per year. Make no more than 4 applications per acre per crop.
  • lambda-cyhalothrin/tebuconazole (Crossover) at 0.14 lb ai/A. PHI 30 days, 7 days for grazing or foraging. REI 24 hr. Do not exceed 0.11 lb ai/A tebuconazole or 0.06 lb ai/A lambda cyhalothrin per season. Do not exceed 8 fl oz/A or 0.139 lb ai/A per season. Barley, triticale and wheat.
  • lambda-cyhalothrin/thiamethoxam (Endigo ZC) at 0.056 to 0.072 lb ai/A. PHI 30 days, 7 days for grazing or foraging. REI 24 hr. Retreatment interval 7 days. Do not exceed 0.06 lb ai/A lambda-cyhalothrin or 0.125 lb ai/A thiamethoxam per season. Groundwater advisory. Barley only.
  • methomyl (Lannate SP) at 0.225 to 0.45 lb ai/A. PHI 7 days. REI 48 hr. Do not exceed 1.8 lb ai/A per season. Do not exceed 4 applications per season. Wheat only.
  • pyrethrin-There are several pesticides containing various amounts of pyrethrins. Check each label for the use and amount needed. Some formulations are OMRI-listed for organic use.
  • spinetoram (Radiant SC) at 0.0156 to 0.047 lb ai/A. PHI 21 day of grain or straw harvest; 3 days of forage, fodder or hay harvest. REI 4 hr. Retreatment interval 4 days. Do not exceed 0.141 lb ai/A per year. Limit 3 applications per year.
  • spinosad (Success, Entrust SC) at 0.031 to 0.094 lb ai/A. PHI 21 days for grain and straw; 3 days for forage, fodder or hay. REI 4 hr. Retreatment interval 4 days. Do not exceed 0.28 lb ai/A per year. Limit 3 treatments per year. Entrust SC is OMRI-listed for organic use.
  • zeta-cypermethrin (Mustang) at 0.022 to 0.05 lb ai/A. PHI 14 days for grain, forage, and hay. REI 12 hr. Retreatment interval 14 days. Do not exceed 0.25 lb ai/A (0.125 lb ai/A for MustangMaxx) per year.