A Guide on How Beneficial Nematodes Kill Soil-Dwelling Insect Pests

There are many types of nematodes, but this post is referring to the three species of beneficial nematodes BioLogic produces (Steinernema feltiae, Steinernema carpocapsae and Heterorhabditis bacteriophora). These beneficial nematodes feed on soil-dwelling soft bodied pest insects only, and pose no threat to humans, pets, plants or other beneficials like earthworms, honey bees or praying mantises. These microscopic roundworms are naturally occurring, but are generally found in populations too low to be effective as pest control. So, by augmenting the natural beneficial nematode population with our products you are able to control a wide variety of common insect pests. This posts intends to explain how beneficial nematodes work to kill soil-dwelling pest insects.

So, how do nematodes work?

There are a few different ways nematodes seek out their prey (e.g. ambush predators or cruising predators), but in general the nematodes will seek out or wait for a pest insect in the soil. Nematodes can move quite a bit vertically, but tend to move less so horizontally in the soil which is why it’s important to apply them properly so they can reach the target insect(s). Once they find their prey, the nematodes will enter through an opening like the mouth or anus of the insect. Once inside, the nematodes release an insect-pathogenic (or “insect-killing”) bacteria that these beneficial nematodes carry naturally. The bacteria and the beneficial nematodes have a symbiotic relationship; the bacteria need the nematodes to transport them into the insect, and the nematodes need the bacteria in order to break down their food (a beneficial nematode probiotic if you will!) The bacteria then multiplies, usually killing the insect within a day or two. This bacteria is not harmful to humans or other vertebrates.  The nematodes actually finish maturing to adults and reproduce inside the insect, before new juvenile nematodes emerge from the pest insect ready to hunt down new prey a week or two later. Since the nematodes reproduce so well inside insects, they are a great longer term natural pest control. Depending on conditions you typically only need to apply once/year (or sometimes less!) as long as you apply in high enough concentrations.

Pretty cool, huh? We think so!