Beneficial nematodes can be a great alternative to chemical pesticides, and a very effective addition to Integrated Pest Management (IPM) programs. However, beneficial nematodes are living organisms and using them for pest control does require accurate information, proper storage and shipping and careful application. Here are some of our top tips and tricks to help you be successful at killing pest insects with nematodes!

(1) Ensure you are buying and applying fresh and living nematodes.

Beneficial nematodes are living organisms, and they need to be living and active in order to provide effective insect pest control. Since a microscope is needed to see the nematodes, most buyers rely on their suppliers to provide them living organisms. For this reason, be sure to buy from a reputable supplier and be sure to buy beneficial nematodes as close to when you plan to apply as possible. There are many reputable garden centers and other re-sellers that take great care to refrigerate their nematodes and sell them in a timely manner, which is critical in ensuring live nematodes. Alternatively, try to buy from a nematode producer directly to get the freshest nematodes available. Plan on buying the nematodes within a few weeks of when you plan to apply (most nematodes have a fairly short shelf life, even when refrigerated). If you are having nematodes shipped to you, be sure they will be packed with ice packs and kept cool during shipment and place them in the refrigerator as soon as you receive them.

(2) Apply at a high enough application rate to kill pest insects. 

If you start to shop around and do some research you will quickly realize that there is a lot of conflicting information out there regarding how many nematodes you need to apply for effective pest control. BioLogic Company recommends treating at a fairly high application rate, about 25,000 nematodes per square foot, to ensure effective control. Beneficial nematodes can travel quite a bit vertically, but do not travel very far horizontally so it is important to apply enough nematodes to effectively kill pest insects in the soil. Additionally, if you apply at high enough levels you can often get away with just one application per season rather than needing to reapply once some of the nematodes die off (depending on a number of factors including temperature, pest population and soil conditions).

(3) Apply at the right time. 

Typically beneficial nematodes can be applied anytime the soil is not frozen. However, depending on which pests you are targeting there may be an ideal time to apply for effective control based on the pests’ life cycle. For example, for white grubs it is best to apply in late summer/early fall or early spring when the young grubs are most susceptible to nematodes whereas any time of year is fine to apply for fungus gnats. BioLogic’s Pest ID includes life cycle information for many common insect pests and provides our recommendation for the best time to apply beneficial nematodes. For all nematode applications we recommend applying in the evening to protect the nematodes (which are sensitive to UV light) from drying out. We also recommend watering the area to be treated well both before and immediately after application.