Various phytophagous arthropods and disease-causing pathogens affect an aquatic plant culture over time. The most commonly encountered pests are aphids, spider mites and lepidopteran (caterpillar) larvae. All three may seriously damage emergent and floating parts of plants. Larvae of
aquatic caterpillar species (eg. Nymphula and Paraponyx spp.) may cause severe damage to cultures of submerged plants.
Once a biological control agent has been successfully established in a region it is sometimes difficult to maintain an insect-free culture of the target plant. Effective control of insects is achieved with non-residual pyrethrin based insecticide spray, while mites are controlled with
miticides. All plants suspected of being contaminated with insect or disease organisms (pathogens) must be isolated from the culture immediately and either treated chemically with appropriate sprays or destroyed. New plants from the field should also be quarantined to prevent introduction of insect and disease organisms to the culture.
