8.2 Biological/Chemical Controls

IPM strategies can also incorporate biological and/or microbial controls. These controls have many ecological advantages, including their host specificity, environmental beneficence, ability to be used in conjunction with chemical application, and that they are nontoxic and nonpathogenic to wildlife, humans, and other organisms not closely related to the target pest. Considering that these are precise, targeted control measures, cost can often be substantial.

Biological controls utilize insect predators of the target pest to control population numbers. While effective, use of beneficial insects may be cost prohibitive for smaller or hobby aquaponic systems. This strategy requires a tight predatory-prey ratio, as prey can be quickly depleted, leaving the beneficial insects with no food source. Predatory bugs such as spiders, ladybugs, praying mantis, bumblebees, and parasitic wasps are effective in combating pests.

Certain plants such as lavender, basil, rosemary, marigold, chrysanthemum, petunias, and carnivorous plants have natural oils and tactics that repel pests such as aphids, thrips, whiteflies, spider mites, and caterpillars. A natural pest repellant can be achieved by having large quantities of these plants inside and outside a plant production area.

Source: Janelle Hager, Leigh Ann Bright, Josh Dusci, James Tidwell. 2021. Kentucky State University. Aquaponics Production Manual: A Practical Handbook for Growers.