What are wireworms?
A They are the grubs or larvae of click beetles, sometimes known as skipjacks. Although there are 60 or so species of click beetles, only five species (Agriotes obscurus, A. sputator, A. lineatus,
Athous haemorrhoidalis and Ctenicera) are troublesome to gardeners.
What to Look for:
Plants may wilt due to larval root feeding. Underground vegetables and tubers will have small burrowed tunnels. Leaves may have holes at the edges where adults feed.
Plants most often affected:
- Roots of many garden ornamental and vegetable plants are attacked.
- Potatoes and tuber growing plants
About the Wireworm
- Wireworms are the larvae of Agriotes and Athous, species of click beetles. •Eggs are laid below the soil between May and June.
- Newly hatched larvae are very small and white. •Larvae grow to 3cm in length, and develop a tough, golden brown skin. They have three pairs of short, stout legs.
- Larvae feed on roots of plants, and burrow into tubers. Potatoes are particularly susceptible.
- The larval period can last up to four years.
- Larvae move up and down in the soil depending on moisture levels.
- Pupation occurs about 30cm below the soil surface in a small chamber.
- After three to four weeks adults hatch and remain in the soil to overwinter.
- Adults emerge in summer to mate.
- When overturned, click beetles propel themselves into the air by arching their back and snapping their head back. This action makes a clicking sound.
There is no chemical treatment for these pests just preventative measures:
- Make sure you rotate suseptable plants away from effected areas for at least 4 seasons.
- Dig the area over in the autum exposing the larve to birds, I alway dig the area over again a couple week before plant my potatoes so the birds get another crack at the wireworms.
- If I spot any while digging I crush them between thumb and forefinger.
- Nematodes (Heterorhabditis megadis) are available which can conontrol populations but multiple applications may be required