In vines and row crops we vary the rows we disperse the cards on. A pregnant female wasp searches out a female CRS and lays eggs inside the scale. The wasp eggs hatch and the larvae of the Aphytis feed on the body of the scale until maturity and then leave as adults to mate and repeat the cycle. Obviously, the CRS female dies as a result. The last type of natural enemies are collectively known as pathogens.
Pathogens are microscopic organisms that can cause a disease in a host insect.
Pathogens induce a disease in their host. Pathogens can be devastating to insect populations when environmental conditions are favorable for development and transmission of disease. Recent advances in technologies for isolating and mass-producing insect pathogens make future prospects look bright for use of these organisms in IPM programs. One of the most exciting groups of new pathogens being studied are the entomophagous nematodes. These nematodes attack only insects.