Final answer:
IGRs such as Bacillus thuringiensis (Bt) disrupt insect development and reduce the need for external insecticides, making them a true form of insect growth regulator that's beneficial for environmental conservation and agricultural practices.
Step-by-step explanation:
The statement that the bait is an IGR (insect growth regulator) can be considered true. Insect Growth Regulators, known as IGRs, are substances that interfere with the development of insects. These are not traditional insecticides that kill insects immediately upon contact or ingestion; rather, they disrupt the normal growth process of insects. This can include inhibiting the larval development or affecting the molting process, ultimately leading to the death of the insect before it reaches maturity or is able to reproduce.
An example of a biologically-derived insect control method is the use of Bacillus thuringiensis (Bt), a bacterium that produces toxins lethal to specific insects. These proteins are activated when ingested by insects, which eventually leads to their death. The introduction of genes encoding these proteins into plants, such as corn, results in the plant producing these insecticidal proteins, significantly reducing the need for external application of insecticides and lowering costs while protecting the environment.
Overall, IGRs and biological control tools like Bt contribute to the management of insect populations and help in the fight against insect resistance, thus benefiting agricultural practices and environmental conservation.