Nematodes are small worm species of about 0.6mm, due to which they can hardly be seen by the naked eye. After administering, nematodes will actively search for prey and penetrate it, after which they secrete bacteria as a result of which the prey is killed. The pest insect then dies within two or three days. Nematodes also use the pest insect as a breeding ground and eat the content of the pest insect.

There are different types of nematodes. The following are the most common species with an explanation of the pest that they control: 

• Steinernema kraussei: Effective against black vine weevil (Otiorhynchus sulcatus), Otiorhynchus armadillo, and Otiorchynchus sallicicola. These nematodes actively seek prey, penetrating and killing them with bacterial secretions.
• Steinernema carpocapsae: Controls bank flies (Scatella stagnalis) and caterpillars.
• Steinernema feltiae: Controls thrips, leaf miners, and fungus gnats. 
• Heterorhabditis bacteriophora: Combats black vine weevil (Otiorhynchus sulcatus), other weevil species such as Otiorhynchus armadillo and Otiorchynchus salicola and the grubs of the rose and cockchafer.

To get the best results from nematode applications, it's important to maintain certain conditions. These include maintaining high humidity, avoiding direct sunlight and ensuring that soil temperatures are between 5°C and 30°C. When applying nematodes, it's recommended to use a sprayer. Ensure continuous agitation of the solution during application to prevent sedimentation of nematodes, which can reduce efficacy. It's important to note that nematode solutions should not be stored for later use, as they may become less effective over time.

Nematodes rapidly multiply and after two to six weeks the new generation will start looking for new pest insects. This multiplication process proceeds continuously, provided that there is enough food (the pest) available for the nematodes, or as long as it takes to wipe out the entire pest. Another condition for the multiplication process is that the soil temperature should not be too low.  

Apart from insect-parasitic nematodes, also plant-parasitic nematodes exist. These do not feed themselves with pests, but with plant material. So, these are the nematodes we don’t want. Examples of plant-parasitic nematodes are the root lesion nematode and the root knot nematode. These pests can be controlled by use of nematicides. 

Can't find your answer? Fill out the contact form and our specialist Kevin van Kester will get back to you. On weekdays, even within 24 hours.