Final answer:
Insect growth regulators (IGRs) are substances that interfere with insect development, particularly affecting larvae rather than adults. They are part of a group of biological control tools that help manage insect populations, including Bacillus thuringiensis (Bt), which is an environmentally friendly and organically approved insecticide.
Step-by-step explanation:
An insect growth regulator (IGR) is a substance that interferes with the development of insects. It typically does not affect adult insects, but targets the larvae, which are often the most destructive stage of the pest. The IGR induces the production of insulin-like growth factors (IGF), stimulating body growth and metabolic rate, leading to abnormal development or death of the insect larvae.
Plants can benefit from producing compounds throughout the year that serve as biological control tools, which may include IGRs. These substances help to protect plants by controlling insect populations, reducing insect resistance, ensuring the safety of the surroundings, and lowering costs.
One example of an organic pesticide that functions as an IGR is Bacillus thuringiensis (Bt), a bacterium that produces toxins harmful to many insect species when ingested. The Bt toxin is safe for the environment, non-toxic to humans, and approved by organic farmers as a natural insecticide.