Nemasys L® Steinernema kraussei

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Nemasys L® biological control agent contains the insect pathogenic nematode, Steinernema kraussei, as infective juveniles. It is used to control black vine weevil larvae in ornamentals and berries.

Key Features

  • Provides at least 4 weeks of protection
  • Steinernema kraussei  will actively seek out vine weevil larvae in the soil.
  • Extremely effective killer of vine weevil larvae
  • Simple and safe to use, kraussei occurs naturally in soils.
  • Apply through ground sprayers or irrigation
  • Apply anytime whenever ground temperatures are above 5oC

Main uses

  • Black vine weevil (Otiorhynchus sulcatus)

How It Works

Harmless to the ornamental crops, humans, the environment and other beneficial insects, these nematodes actively seek out vine weevil larvae by swimming in the thin film of water on soil particles.  They locate hosts by detecting carbon dioxide and other waste products. After locating pest larvae, nematodes invade through natural body openings and inject bacteria into the insect. Bacteria develop within the insect and it dies of septicemia.
Under optimum conditions, the insect can die within 12-24 hours. Insect mortality will depend on the environmental temperature. The minimum soil temperature should be 5°C for nematodes to work most efficiently and the maximum soil temperature should be no more than 26°C.

Available delivery systems

Nemasys L® is available in units of 50 million, 250 million entomopathogenic Steinernema kraussei nematodes in an inert carrier in sealed trays.

Handling & Storage

Instruction for use

  • Apply early morning or late evening to minimize the effect of heat and sunlight. Turn off artificial lights which may dry plant surfaces too quickly.
  • The soil surface should be moist at the time of application.
  • Apply with at least 4 litres / m2 water if applied direct to soil.
  • For drench applications over foliage use lower volumes of water and irrigate within 30 minutes of treatment with at least 1 litre/ m2 to wash nematodes off the leaves and below the soil surface.
  • For optimum results, keep the soil moist for 3-4 weeks after application.
  • The entire spray solution should be applied once mixed. Do not store for longer than 4 hours.
  • Remove all fine filters in the tubing and at the nozzles. Use nozzles with at least 0.8 mm diameter.
  • Keep nematode solution agitated continuously; alternatively add carboxy-methyl cellulose (wallpaper paste) at 0.4% w/v to prevent nematodes settling, mixture should still be used within 4 hours.
  • Ideal soil pH is 5-7. Correct alkaline conditions to improve performance
  • Do not exceed a pump pressure of 20 bar/ 300psi, for Dosatron 6 bar/ 100psi.
  • For detailed instructions on application techniques, download the technical sheet or consult your Bioline advisor for more information.


  • Avoid mixing with pesticides and adjuvants (wetting agents) unless compatibility checked.
  • Ask your supplier; otherwise avoid application 1 week before and 2 weeks after application of pesticides.
  • DO NOT mix with fertilizers. However, fertilization directly before or after application will not be a problem.

Storage and transport

  • Use as soon as possible upon delivery.
  • Use the entire pack at one time.
  • The product may be stored for a limited period of time at 4 to 8°C. (See expiry date on the package).
  • Store bags in a refrigerator without the box; In a cool storage room - open the carton but not the bag.