Thrips Thrips are another problem that responds to lacewing releases. Since I expect the biological control agents to die out in the summer, the spring release that includes lacewings is valuable. The crypts are mainly for mealybug control, but will also feed on thrips. The thrips have never built up to the point where they have caused damage to my succulents. My major control is to maintain healthy plants.
Thrips seem to prefer damaged or unhealthy specimens.
Fungus Gnats Nematodes are my primary control for fungus gnats and other soil-borne organisms. I water them into the soil every four months. Plants in a high mineral soil have less of a problem since fungus live on the soilUs organic material. With an unlimited supply just outside the door, I am certain that I will be dealing with fungus gnats as long as I have my greenhouse. I use BtI on occasion in the winter when the population has gotten out of control, but through much of the year I tolerate a modest population.