Since you can’t use pesticides in aquaponics, you need to be vigilant in your pest scouting efforts and quick to react if you see any pest problems. Pest control in aquaponics is really about prevention through good management practices such as writing and following a bio-security program, regularly monitoring and scouting for pest insects, keeping weeds and debris from growing around the outside periment of the greenhouses, installing proper insect screening on greenhouse openings and keeping the greenhouse clean and free of dirt and dead or dying plant material.
In over 20 years of operating commercial hydroponic and aquaponic greenhouses and consulting in the same field, I consistently see that the growers who keep their greenhouses clean and crops healthy rarely experience any pest problems. Plant debris and unhealthy plants attract pest insects. Healthy plants repel pest insects.
If you do discover pest insects in the greenhouse, don’t panic. There are natural ways to control them. First, though, you need to properly identify the pest and then determine what the biological control is. Most often, this will be another insect that is either a predator or parasite to the pest insect. A predator, like the lacewing shown to above, eats the pest insect. A parasite will disrupt the life cycle of the pest insect.
At the same time you are ordering beneficial insects, physically remove the affected plants along with the pest insects as best you can. When the beneficial insects arrive, distribute as directed by the supplier and let them do their thing. Biological pest control is a fascinating and effective means of controlling pests when you are in a well-constructed, controlled environment greenhouse.