Wireworms
Agrypnus spp.; Heteroderes spp.
Slender yellow-brown larvae of click beetles that bore into root crops, potatoes and germinating seed.
Background
Wireworms are the soil-dwelling larvae of click beetles. They spend 1-3 years in the soil feeding on roots, germinating seeds and tubers. They are a particular problem after newly broken-up pasture or weedy ground, and in gardens that have not been cultivated for a few years.
How to identify
- Larvae: slender, tough, segmented, yellow-brown, 15-25mm long, with a hard smooth skin
- Adults (click beetles): 8-15mm, brown or black, flip themselves audibly when placed on their back
- Damage: bored holes in potatoes and carrots, chewed germinating seed, wilted seedlings with hollowed roots
Life cycle
Long life cycle — 1-3 years as larvae, depending on species. Adults emerge in spring, lay eggs in soil, larvae feed for multiple seasons before pupating.
Weather triggers
- Temperature: 8-25°C
- Move up to surface in moist cool soil. Burrow deeper in hot dry weather.
Peak season (southern hemisphere)
Red = active season · Dark red outlined = this month
Affected vegetables & crops
Click any crop to see current prices and growing info.
Climate zones at risk
Organic & low-impact control
- Trap with halved potatoes buried 5cm deep on sticks — dig up weekly and destroy captured wireworms
- Cultivate soil in winter to expose larvae to frost and birds
- Rotate away from root crops on newly broken ground for 1-2 seasons
Chemical control
- No home-garden registered soil insecticides for wireworm
Always read product labels — registrations change.
Prevention
- Avoid planting susceptible crops in recently de-grassed ground
- Maintain active soil life with compost and regular cropping
Companion planting
Mustard green manure grown and incorporated before flowering has some suppressive effect (biofumigation).
Biosecurity
Native and widespread.
Sources
- GRDC — Wireworm fact sheet
- NSW DPI — Wireworm damage in vegetables
Accuracy confidence: medium. We update this library as new extension guidance is published.