Wireworms

Pest ID of Wireworms

Wireworm Larvae

Wireworm larvae have shiny yellow to brown hard bodies or creamy white
soft bodies with dark and hardened heads and tails.

Click Beetle (wireworm adult)

Adult wireworms, known as "click beetles," are yellow, brown, black,
or gray and slender with a bullet-shaped abdomen.

Related Species with Look-Alike Symptoms

Billbug: adult and larvae feed on young seedling; adult may feed

to growing point and make similar row of holes in expanding leaves
(two photos below)

Stinkbug: may probe seedling and dissolve growing point causing 
stunting, tillering and holes in leaves (two photos below)

Cutworm: feeding on growing point may cause stunting, holes in 
leaves or tillering (two photos below)

Seed Corn Beetle: damaged kernel or young seedling
(two photos below)

White Grub: root feeding causes uneven emergence and early growth; white grubs are often found along with wireworms in areas of the field

Seed Corn Maggot: feeds on germ, hollowing out the kernel; 
maggot (larva) or pupa may be present

Facts on Wireworms

• Wireworms are the larvae of many beetle species from Agriotes, Conoderus, Limonius, Hemicrepidius and Melanotus genera
• Wireworm species are destructive pests of crop plants worldwide, especially in temperate regions
• Wireworms are important in many spring-seeded crops because of potential stand losses
• In most cases, wireworms are spring pests only as they move deeper and may aestivate as soils warm during the summer
• Hosts: any fibrous rooted plant species, including corn, pasture, small grains and other grasses
• Larvae are opportunistic; unable to move more than a few inches, they must feed on what is present.

Life Cycle of Wireworms

• Wireworms develop through complete metamorphosis
  • Egg, larva, pupa, adult
• Eggs are laid in the soil
• Larvae development can require one to five years depending on species; some species require six years per generation
• Generations often overlap
• Overwinters in soil
• Adults are known as click beetles

Key Characteristics of Wireworm Damage

• Missing plant or seed
• Stunted or misshapen seedling
• Holes across leaves as whorl unrolls
• For positive ID, wireworm must be found

Impact on Crop

• Wireworms feeding on the seed may prevent germination and give rise to missing plants and uneven stands
• Feeding on the young plant or root system can give rise to uneven plant development and lower ability of the affected plants
  to compete
• Feeding on the whorl or growing point above the seeds may stunt, kill plants or give rise to abnormal development
• Yield loss is common when stands are damaged