Q:Will the biocontrol insects eat my other plants?
A: No. The primary consideration in selecting biological control agents is host-specificity. Host-specificity means that agents will only feed and complete their development on the target plant. Only agents that are believed to have a narrow host range are brought into the US, and then they undergo intensive screening in an approved biological control quarantine facility to make absolutely sure that the target plant is their only host.
In quarantine, a long list of test plants, including species that are related to the target, endangered or threatened species and economically important plants are exposed to the candidate biological control agents in no-choice feeding conditions, meaning that the proposed agents either feed on the test plant or die of starvation. Additional testing is conducted to make sure that adult females of the agents will only lay their eggs on the target plant. The historical record clearly shows that this methodology works, as there have been no recent examples of biological control agents attacking non-target plants.