Small grain-Wireworm


Sugar beet wireworm (Limonius californicus)

Western field wireworm (Limonius infuscatus)

Great Basin wireworm (Selatosomus pruinina)

Pest description and crop damage Larvae (wireworms) are up to 0.75 inch long, yellowish, hard-bodied, and shiny. In the case of fall-sown wheat, larvae burrow into kernels or leaf whorl above seed. In spring seedlings, larvae attack kernels or underground portions of plant after sprouting. Damage is more severe in cool, wet spring weather.

Management-chemical control

Wireworms are usually a localized problem. However, in recent years they resurged as significant pests of small grains in the PNW. Be sure to use seed treatments for wheat and barley. While wireworms can cause damage in both wheat and barley, studies have indicated that barley is relatively more tolerant of the damage. Warning: Treated seed must not be used for food or livestock feed. If a proprietary seed dressing is used, follow manufacturer's directions.

Seed treatments

  • broflanilide (Terraxa) at 0.26 oz/100 lbs seed (0.005lb ai/100lbs of seed). Do not apply more than 0.0445 lb ai/acre per application and/or per year total, including seed treatment (when applicable) and soil application. WA only.
  • clothianidin/metalaxyl/metconazole (NipsIt Suite) at 5 to 7.5 fl oz (0.01 to 0.015 lb ai) /cwt seed. Do not exceed 6.4 oz ai/a clothianidin per season. Barley, oats and wheat only.
  • clothianidin (NipsIt Inside) at 0.01 to 0.07 lb ai/100 lb seed on-farm application. Do not exceed 0.2 lb ai/a clothianidin per year.
  • imidacloprid (Gaucho 600F, Sativa IM RTU) at 0.005 to 0.01 lb ai/100 lb seed (0.13 to 0.26 fl oz). Do not graze or feed livestock on treated areas within 45 days after planting. Wheat, barley, oats, rye and triticale.
  • imidacloprid/metalaxyl/tebuconazole (GauchoXT) as seed treatment at 3.4 to 4.5 fl oz (0.031 to 0.041 lb ai) /100 lb seed; early season protection. Do not graze or feed livestock on treated areas within 45 days after planting. Wheat, oats and barley only.
  • thiamethoxam (Cruiser 5 FS, Warden Cereals 360) at 0.19 to 0.25 fl oz (0.007 to 0.01 lb ai) per 100 lb seed (wheat and barley). Do not graze or feed livestock with 45 days of application. Other seed protectants containing thiamethoxam as the only insecticide include: Cruiser Maxx and Cruiser Vibrance Quattro.
  • thiamethoxam/difenoconazole/mefenoxam/fludioxonil/sedaxane (Cruiser Vibrance Quattro) at 0.02 to 0.032 lb ai/100 lb seed. Feeding restrictions apply.