Wireworms (click beetle larvae)
Agriotes spp.
Role in the garden
The yellow, hard, shiny larvae of click beetles, which live for several years in the soil and bore into tubers, roots and young seedlings: the holed potato is the best-known symptom.
Activity period
Larvae active in spring and late summer, in the top 20 centimetres of soil
Practical guide
Where to find them
Mainly in ground recently turned after a meadow or fallow, where the females laid in the grass; cool, moist soils. Larvae of 1 to 2.5 cm, orange-yellow, with a rigid body.
Prevention
Avoid planting potatoes the year after a meadow is turned over, prefer little-affected crops (peas, beans) in the first two years, harvest potatoes promptly at maturity, loosen the soil in late summer to expose larvae and pupae to birds and ground beetles.
Sources
- INRAE, Ephytia : jardibiodiv, Élatéridés (taupins)
- ARVALIS : fiches accidents Taupins (blé, orge, maïs)
- RHS : Wireworms (rhs.org.uk)
Favourite plants / resources
Related plant entries
Carrot
In the vegetable garden, the carrot is planned first and foremost around its pest, the carrot fly, hence the value of interplanting it with onions. Its taproot needs loose, deep, stone-free soil (RHS), without a heavy application of manure just before (GAB/FRAB Bretagne). And when left to flower, this umbellifer opens up umbels that feed hoverflies and other small beneficials, like the other Apiaceae so valued for drawing in pollinators and aphid predators.
Onion
The sulphur compounds released by the bulbs are reported to repel several pests (the carrot fly in particular), an effect documented in the laboratory, moderate in the garden. Like the other alliums, tradition keeps it away from legumes, with no effect on their nodulation demonstrated in the field.
Maize (corn)
A living stake for the Three Sisters, maize raises the vertical storey around which the whole planting is organised: its sturdy stalk carries the climbing bean, which fixes nitrogen and returns part of it to the soil for the following crops, while the squash spreads a living mulch across the ground that curbs evaporation and weeds. A heavy feeder and thirsty by nature, it calls for rich, deep soil, something a rotation with legumes helps to prepare. Its tall silhouette can also serve as a windbreak or cast light shade over lower crops that suffer in the heat.
Potato
A nightshade with traditional planting (April) or grown under mulch (Charles Dowding) requiring zero earthing-up. Demanding in manure, it readily heads the rotation on an enriched bed (GAB/FRAB Bretagne). Not to follow or precede a tomato on the same bed (shared blight, Phytophthora infestans).