Small grain-Wireworm


Sugar beet wireworm (Limonius californicus)
Western field wireworm (Limonius infuscatus)
Great Basin wireworm (Selatosomus pruinina)

Pest description and crop damage Wireworms are the larvae of click beetles. The adult beetles have elongated bodies with almost parallel lateral sides, and do not cause crop damage. Wireworms are the only damaging developmental stage. They are up to 0.75 inch long, yellowish or brownish, hard-bodied, and shiny. Wireworms burrow into planted seed, emerging sprout, or underground portions of the seedling. Wireworm feeding at the base of the seedling stem can result in wilting and death of the central leaf (a.k.a. "Deadheart"). 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 lb seed (0.005lb ai/100lbs of seed). REI 12 hr. Do not apply more than 0.0445 lb ai/A per application and/or per year total, including seed treatment (when applicable) and soil application. Ground water advisory.
  • clothianidin (NipsIt Inside) at 0.25 to 1.79 fl oz (0.01 to 0.07 lb ai)/100 lb seed on-farm application. REI 12 hr. Do not exceed 0.2 lb ai/A clothianidin per year.
  • clothianidin/metalaxyl/metconazole (NipsIt Suite) at 5 to 7.5 fl oz (0.01 to 0.015 lb ai) /cwt seed. REI 24 hr. Do not exceed 0.4 lb ai/A clothianidin per cropping cycle. Barley, oats, and wheat.
  • imidacloprid (Gaucho 600F, Sativa IM RTU) at 0.13 to 0.26 fl oz/100 lb seed (0.005 to 0.01 lb ai). Do not graze or feed livestock on treated areas within 45 days after planting. REI 12 hr.
  • imidacloprid/metalaxyl/tebuconazole (GauchoXT) 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. REI 24 hr. Groundwater advisory: metalaxyl is known to leach through soil into groundwater under certain conditions as a result of agricultural use. Wheat, oats, barley.
  • 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. REI 12 hr. Ground water advisory.
  • thiamethoxam/difenoconazole/mefenoxam/fludioxonil/sedaxane (Cruiser Vibrance Quattro) at 0.042 to 0.049 lb ai/100 lb seed. Do not graze or feed livestock on treated areas for 45 days after planting. REI 48 hr. Ground water advisory.