Vine Weevil Pest Solution: Nemasys Vine Weevil (contains the Steinernema kraussei nematode)

Nemasys Vine Weevil Description

Nemasys Vine WeevilSteinernema kraussei are tiny parasitic eel worms (nematodes). Barely visible to the naked eye, they occur naturally in British soils.

The nematodes are mixed with a carrier medium to make Nemasys Vine Weevil , this is the form in which they are despatched.

Nemasys Vine Weevil Life Cycle

The nematodes live in moisture surrounding soil particles. They seek out vine weevil grubs and enter them through body openings. Once inside the grub, the nematodes release a bacteria which kills it within 48 hours.

The dead grub then starts to decompose. The nematodes reproduce inside the dead grub and are then released back into the soil to infect more vine weevil grubs.

If there are no grubs present in the soil the nematodes will die out after a few weeks.

Nemasys Vine Weevil Usage

  • Nemasys Vine Weevil  will kill vine weevil grubs, it has no effect on the adults or eggs.
  • Nemasys Vine Weevil  can be used in pots and containers as well as open borders. It can also be used on all plants including edible ones.
  • Nemasys Vine Weevil should be applied to moist soil or compost, the area treated should be kept moist by normal watering after application to enable the nematodes to swim in the soil moisture.
  • Nemasys Vine Weevil  is most effective at soil temperatures above 5ºC (41ºF).
    NB. Soil temperature is more stable than air temperature. 
  • Nemasys Vine Weevil  is simply applied as a drench and will kill all vine weevil grubs present in the treated area.
    NB. If there are no grubs present the nematodes will die out.
  • Nemasys Vine Weevil can be kept in a fridge NOT freezer at 5ºC for use before the pack expiry date (about one to two weeks after delivery date), however it is best used immediately upon receipt.
  • Nemasys Vine Weevil  is best applied in the spring (March/May) and autumn (late August/November), these are the times that most vine weevil grubs will be present in the soil.
  • Like all Defenders biological controls, Nemasys Vine Weevil is harmless to children, pets and wildlife and will not become a pest in its own right.

Biological Vine Weevil Control Product Details


Area Treated


Small Pack

The standard pack contains 6 million nematodes and treats an area of 6 square metres of open ground (beds, borders etc.) or 12 square metres of pots and containers (approx. 150 x 30cm (12") pots).


Large Pack

The large pack contains 50 million nematodes and treats an area of 50 square metres of open ground (beds, borders etc.) or 100 square metres of pots and containers (approx. 1250 x 30cm (12") pots).


All packs of Nemasys Vine Weevil  are sent with complete instructions, and a free information sheet on Biological Vine Weevil Control entitled "Your Questions Answered".