Nemasys H

Nemasys® H is a biological control which effectively targets larval stages of the black vine weevil in soil or container-grown crops.

Nemasys H

Nemasys® H is a biological control which effectively targets larval stages of the black vine weevil in soil or container-grown crops.


  • Effective natural control
  • Protects the root system preventing subsequent larval feeding damage and plant loss, particularly for container-grown plants
  • Larvae and pupae treated with Nemasys® H will not develop into adult vine weevils, eliminating unsightly damage to the foliage (typical leaf notching)
  • The nematodes persist for approximately 4 weeks in moist soil to protect against newly emerging larvae
  • Eliminates the potential for chemical residues in produce
  • IPM-compatible
  • No pest resistance issues

Why Nemasys H?

Product Profile:

Active ingredient(s)Heterorhabditis bacteriophora (82%)
FormulationPaste (PA)
Pack size50 million or 250 million
Area treated- 50 m2 open soil or 100 m2 pots/containers or 2000 strawberry plants (50 million pack)
- 250 m2 open soil or 500 m2 pots/containers or 10,000 strawberry plants (250 million pack)
CropsAny soil or container-grown crop including soft fruit and ornamentals
Pest activityBlack vine weevil (Otiorhynchus sulcatus) larvae and pupae
Rate of applicationOpen soil: 1,000,000 nematodes per m2 Pots/containers: 500,000 nematodes per m2 Strawberry: 25,000 nematodes per plant
Frequency of applicationOnce a month.
Time of applicationWhen black vine weevil larvae and pupae are present in the soil or growing medium. Typically, applications should be made between August and October to control larvae hatching from summer and autumn-laid eggs.
Water volumeOpen soil: 4.0 litres per m2 Pots/containers: 4.0 litres per m2 Strawberry: 100 ml per plant
Aquatic buffer zoneNone

Why Nemasys® H?

Nemasys® H is a biological control product containing nematodes, which effectively controls larvae and pupae of the black vine weevil (Otiorhynchus sulcatus) in soil or container-grown crops, including soft fruit and ornamentals. Infected larvae stop feeding and further root damage is prevented. Infected larvae and pupae fail to develop into adult beetles, thus preventing the characteristic notching seen on leaves. Nemasys® H is for application at warmer soil temperatures (12-30 oC); for applications at 5-12oC use Nemasys® L. Nemasys® H persists for approximately 4 weeks in moist soils. Nemasys® H is compatible with IPM (Integrated Pest Management) systems and organic farming. There is no known resistance of the garden chafer to Nemasys® H.

How to get the best from Nemasys® H:

  • Apply when soil temperature is between 12-30oC
  • Use immediately on receipt of packs or refrigerate at 5oC (do not freeze)
  • Avoid application in direct sunlight; nematodes are uv-sensitive, so apply on a dull day or in the evening
  • Apply when the soil or growing medium is moist, or irrigate thoroughly before application
  • Use within expiry date
  • Use the entire pack and do not store stock solution or diluted product
  • Make a stock solution as directed on the label, making a paste in the first instance and then adding remainder of the water, to avoid lumps forming; this solution should be mixed thoroughly to ensure nematodes are well dispersed and kept agitated
  • Application can be made via conventional sprayer with a lance, by boom or by sprinklers, selecting nozzles (aperture should be greater than 0.5 mm) to give a coarse spray, via Dosatron or via drip irrigation
  • Remove all fine filters (50 mesh or smaller) from the application equipment
  • Partially fill tank with water, add stock solution, fill with water to the required level and maintain agitation
  • Do not exceed 300 psi/20 bar/2000 kPa pump pressure
  • If product is applied over the foliage, irrigate immediately with water to wash the nematodes into the soil or growing medium; keep this moist for at least two weeks after application

Disclaimer: photo kindly provided by Ward Stepman