How to spot and deal with vine weevils
What to look for, what to do, and how to stop them coming back
Vine weevils are one of the pests we find on Aeoniums. The adults chew the leaves and the grubs eat the plant from underneath, so it helps to know what each stage looks like.
Spotting the adults
In spring, most of the damage is done by the adults. They are beetle-like insects that come out after dark and nibble the edges of the leaves, leaving them notched. We found that going out at night makes them easy to pick off the plants. We typically find one vine weevil per plant, and each adult can lay up to 500 eggs, so a torch and a quiet half hour in the garden are well worth it.
Spotting the grubs
Adults lay their eggs in the compost over summer, so by autumn the cream-coloured, C-shaped grubs are eating the roots and tunnelling into the base of the stem. They work out of sight, and the first sign is often a plant that wilts, wobbles in its pot or falls over. Other signs are a shrinking rosette, heavy leaf drop and a soft stem base.
Treating them
If you suspect grubs, tip the plant out and check the root ball. Pick out any grubs and look for tunnels at the base of the stem. If the stem has been hollowed out, cut above the damage and treat the top as a cutting.
- Adults: pick them off by hand at night.
- Grubs in the soil: vine weevil nematodes (Steinernema kraussei) attack them. You water them into the compost, and they work while it is above 5°C, so early autumn is a good time to apply them.
- Severe infestations: use an insecticide labelled for vine weevil, as a last resort.
Stopping them coming back
Repot in late summer or early autumn and inspect the lower stem and roots as you do. That clears out any eggs and grubs before they can do real damage. Use fresh soil and clean the pots, ideally at the end of summer, before the grubs are most active.
A quick look over your plants each week lets you catch problems early. At our nursery we use nematodes rather than chemical sprays.
Our Ultimate Aeonium Autumn Care Guide covers the rest of the autumn jobs, including repotting.
For compost, perlite and grit, see our Compost & Extras collection.