Which statement best describes Insect Growth Regulators (IGRs)?

Which statement best describes Insect Growth Regulators (IGRs)?

• A. Groundwater contamination
• B. Insect development and life cycle disruption
• C. Nutrient uptake in plants
• D. Immune response in insects

Answer: (B)

IGRs work by disturbing the hormonal signals that govern insect growth and development. They either imitate juvenile hormone, which keeps insects in a immature state and prevents proper maturation, or interfere with the hormones that trigger molting, so insects can’t progress from larva to pupa or from pupa to adult. Because the growth cycle is disrupted, immature stages may fail to reach adulthood or emerge malformed, leading to reduced pest populations. This mechanism focuses on development and life cycle timing rather than immediate killing or environmental contamination, which is why describing IGRs as disrupting insect development and life cycle best captures their action. The other options describe effects (like groundwater issues, plant nutrient uptake, or insect immune responses) that aren’t how IGRs work.

IGRs work by disturbing the hormonal signals that govern insect growth and development. They either imitate juvenile hormone, which keeps insects in a immature state and prevents proper maturation, or interfere with the hormones that trigger molting, so insects can’t progress from larva to pupa or from pupa to adult. Because the growth cycle is disrupted, immature stages may fail to reach adulthood or emerge malformed, leading to reduced pest populations. This mechanism focuses on development and life cycle timing rather than immediate killing or environmental contamination, which is why describing IGRs as disrupting insect development and life cycle best captures their action. The other options describe effects (like groundwater issues, plant nutrient uptake, or insect immune responses) that aren’t how IGRs work.