BASF Agricultural Solutions UK

Nemasys M

Nemasys® M is a biological control which effectively targets the larval stages of sciarid flies in mushrooms.


  • Effective natural control
  • The potential for a high level of crop loss from the sciarid larvae burrowing into the mushroom stalks and up into the cap is reduced
  • Eliminates the potential for chemical residues in mushrooms ·
  • Organic farming and IPM-compatible
  • No pest resistance issues
 Technical Services Hotline +44 845 602 2553

Technical Services Hotline +44 845 602 2553

Technical Services Hotline

Why Nemasys M?

Product Profile:

Active ingredient(s)Steinernema feltiae (90%)
FormulationPaste (PA)
Pack size150 million or 250 million
Area treated150m2 (150 million pack) or 250 m2 (250 million pack)
Pest activityLarval stages of sciarid flies (Lycoriella spp.)
Rate of application1,000,000 nematodes per m2
Frequency of applicationTwo applications per crop
Time of applicationPhase II growing: Drench at casing and again one day after casing
Phase III growing: Drench two days after casing again three days after casing
Water volumeMinimum 1 litre per m2
Aquatic buffer zoneNone

Why Nemasys® M?

Nemasys® M is a biological control product containing nematodes, which effectively controls the larval stages of sciarid flies (Lycoriella spp.). When applied at the correct timing, the sciarid larvae are prevented from burrowing into the stalks and up into the caps, reducing the potential for a high level of crop loss. Nemasys® M is compatible with IPM (Integrated Pest Management) systems and organic farming. Nemasys® M persists for approximately 4 weeks in moist mushroom compost, thus protecting against newly emerging sciarid larvae. There is no known resistance of sciarid fly larvae to Nemasys® M.

How to get the best from Nemasys® M:

  • Apply when the substrate is between 10-30 oC
  • Use immediately on receipt of packs or refrigerate at 5oC (do not freeze)
  • Apply as a two-application drench programme as detailed on the label
  • 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 is as a drench to the casing surface via watering tree, lance or sprinklers, selecting the nozzle to give a coarse spray; the nozzle aperture should be greater than 0.5 mm. A Dosatron unit can be used.
  • 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

Disclaimer: photo kindly provided by Ward Stepman