Insect
Wireworm
Shiny orange-brown, tough-skinned beetle larvae up to 25 mm long found tunnelling through roots, tubers, and bulbs in the soil.
Symptoms to Look For
- Seedlings collapsing at soil level with roots tunnelled through
- Potato tubers with round entry holes and internal tunnels
- Irregular wilting and death of scattered plants across a bed
Affected Plants
PotatoCarrotBeetrootOnionCornBeanBrassicaLettuce
Organic Solutions
Trap baiting
Bury halved potato pieces on skewers 10 cm deep at 1 m intervals; check every 2 - 3 days and destroy any wireworms found.
Cultivation
Dig and fork beds frequently in late summer and autumn to expose wireworms to birds and desiccation.
Beneficial nematodes
Apply Steinernema kraussei nematodes to moist soil in late summer to target young wireworm larvae before they burrow deep for winter.
Prevention
- Avoid planting root crops in newly broken grassland where wireworm populations are highest
- Follow with a green manure and thorough cultivation for a full season before planting susceptible crops
- Harvest potato tubers as soon as mature to reduce exposure time in the ground
Garden, by Willowbottom recommends only organic, wildlife-friendly solutions. No synthetic pesticides, no harmful chemicals - ever.