Avoid application in the late fall since they move down in the soil in the winter or late spring as they prepare to pupate. Additionally, some species of nematodes can actively seek out their hosts and kill them rapidly. They multiply quickly within the host and release thousands of mobile offspring. Although there have been many successful field applications of entomopathogenic nematodes, applications do not always yield the desired results. Adverse environmental conditions at the time of application and for several weeks after can cause poor results.
Nematodes are sensitive to sunlight and they are prone to desiccation.
Nematodes require high relative humidity, as well as a film of water on leafs and soil on which to move. Nematodes should be applied early in the morning followed by a half inch of water applied through irrigation. Nematodes are living organisms and must be treated with care and applied at recommended rates in order to achieve success. Biorational controls used in combination may impart a synergistic mortality on grub populations.