Slug Pest Solution: Nemaslug (contains the Phasmarhabditis nematode)

Nemaslug Description

Slug ControlPhasmarhabditis is a tiny parasitic eel worm (nematode), barely visible to the naked eye, which occur naturally in British soils.

Nemaslug contains these nematodes mixed with a carrier medium.

Nemaslug Life Cycle

The nematodes live in moisture surrounding soil particles, they seek out slugs and enter them under the mantle.

Once inside the slug, the nematodes release a bacteria. Infested slugs will stop feeding within five days and go underground to die.

The nematodes reproduce inside the slug as it dies and are released back into the soil after the slugs death to infect more slugs.

Nemaslug Use

  • Nemaslug will control most ages and species of slugs. Small to medium sized slugs burrow underground during the day, where it is moist. Large slugs over 8 cm, which are found in some parts of the country, are less able to burrow underground and therefore tend to live on the soil surface, Nemaslug is less effective at controlling these.
  • Nemaslug may affect water snails. To avoid harming water snails keep the treatment 3m away from ponds.
  • Nemaslug 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.
  • Nemaslug needs a minimum soil temperature of 5ºC (40ºF).
    NB. Soil temperature is more stable than air temperature.
  • Nemaslug is simply applied as a drench, and will be effective for at least 6 weeks after which time a repeat application may be necessary.
  • Nemaslug 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.
  • Nemaslug is harmless to children, pets and wildlife. 

Biological Slug Control Product Details

Defenders supply Nemaslug in 2 pack sizes. The nematodes are suspended in a carrier and supplied in a sachet, simply mix with water and apply to the soil as a drench using a watering can and coarse rose.

Once opened the entire contents of the packet MUST be used at the same time.

Nemaslug is recommended outdoors between 1st March and 31st October. Under protection they can be used any time if temperatures exceed 5ºC.


Area Treated


Standard Pack

Contains 12 milion nematodes and treats an area of 40 square metres


Large Pack

Contains 30 million nematodes and treats an area of 100 square metres 


All packs of Nemaslug are sent with complete instructions on the packaging.

NB: Nemaslug is produced in a high tech fermentation process and each batch of product is subjected to extensive QC testing before despatch. In the event of a batch failing the tests, Nemaslug may become temporarily unavailable