Stefan Buczacki problem solves
Stefan says: I'm sure if you look carefully at your plants you'll find that rather than little holes, you'll see small wavy notches. It's a highly characteristic symptom of damage done by adult vine weevils . Generally, though, this isn't as bad as the damage caused by the soil-inhabiting larvae, which are seriously harmful to plants, such as primulas and fuchsias, especially those growing in greenhouses.
The damage caused by adult weevils may be disfiguring on evergreen shrubs like laurel, but in the long term, it's less serious and no treatment is needed.
The vine weevil is nonetheless a remarkable and highly successful little beast – on two counts. First, unlike most beetles, it can't fly and has to crawl everywhere, but has nonetheless managed to become extremely widespread.
Second, most other beetles reproduce sexually, but virtually all vine weevils are female and they must therefore reproduce by what is called parthenogenesis. Each female lays hundreds of eggs in soil or potting compost during the spring and summer, close to suitable host plants.
The larvae hatch after about two weeks and feed on plant roots before pupating in the soil. The adult weevils hide at soil level during the day, in leaf litter, loose brickwork and woodwork and similar situations, and crawl up onto plants after dark.
The best control, especially in greenhouses, is by using cultures of nematodes or eelworms. The live creatures are supplied in a carrier which is mixed with water to produce a live suspension of nematodes. These are then watered
into infested pots where the nematodes search for vine weevil larvae and enter their bodies. Once inside, the nematodes release pathogenic bacteria which kill the larvae within a couple of days.
The treatment is most effective when applied in late August and early September when the population of vine weevil larvae is at its maximum.