Wireworm
Beginner
Scientific Name
Various Coleoptera species
Identification
- Copper-coloured, cylindrical and hard-bodied
- 3 pairs of tiny legs near the head-end
- Vary in size from a few millimetres to 2 cm (3/4 in.) in length
- Infested plants do not develop well, the seedlings lack vigour or fail to emerge
- Damage is often scattered randomly across the field
Often Confused with
Millipedes
Seedcorn maggot
Cutworms
Period of Activity
Wireworms are present all season. Young plants are most susceptible; therefore early-season control is critical. Wireworms have a life cycle of several years. They are likely to be present in fields with a history of the problem or in fields that have recently had sod crops.
Scouting Notes
Wireworms may be monitored in the fall (or in the early spring for later-planted crops) using bait stations. Bury whole carrots, 7.5 cm (3 in.) deep, at 10 marked stations across the field. Check the stations in 2–3 days.
Thresholds
A count of 0.5 to 1 wireworm per station indicates a potential problem.
Advanced
Scientific Name
Various Coleoptera species
Wireworms are the larvae of Click Beetles. Wireworm feeding is most severe during cool, wet springs when germination and early growth are delayed. Wireworm may be present in any soil type, however, populations are often most damaging on coarse sandy-loam soils.
If cucurbits are planted into fields with high wireworm populations, large numbers of plants can be quickly destroyed.
Identification
Wireworms are dull brown or copper coloured, with a cylindrical, hard body. They are approximately ½ to 1 cm (1/5- 2/5 in.) in length with three pairs of legs at the head-end of the body.
They feed on seeds, emerging seedlings and young roots, causing the plants to rapidly wilt and die.
Often Confused with
Millipedes
Seedcorn maggot
Cutworms
Biology
Wireworm eggs are often laid in small grains, sod or in fields with grassy weed escapes. Many wireworm species have an extended lifecycle. As a result the larvae may be present in a field for 2- 5 years.
Wireworms are most noticeable during the fall and early spring when they come to the soil surface to feed on roots and decaying residue. During the heat of the summer and the winter months, wireworm larvae will migrate deep into the soil for protection.
Period of Activity
Wireworms are present all season. Young plants are most susceptible; therefore early-season control is critical. Wireworms have a life cycle of several years. They are likely to be present in fields with a history of the problem or in fields that have recently had sod crops.
Scouting Notes
Wireworms may be monitored in the fall or in the early spring using bait stations.
Thresholds
A count of 0.5 to 1 wireworm per station indicates a potential problem. Make your planting and seed treatment decisions accordingly.
Management Notes
- Plant into warm soils (>16°C, 60°F).
- Good early growth will help reduce the losses to this pest where populations are low-to-moderate.
- Use bait stations to identify (and avoid) fields with high wireworm populations.
