Which larvicide is characterized as a synthetic analog of juvenile hormone?

The correct answer is Methoprene, which is recognized as a synthetic analog of juvenile hormone. Juvenile hormone is a key regulator of insect development and is crucial for maintaining the larval stage in many insects. By mimicking this hormone, Methoprene interferes with the normal hormonal processes that govern insect growth and maturation. As a result, it prevents larvae from developing into adults, effectively reducing their populations.

In contrast, Temephos is an organophosphate insecticide that works by disrupting the nervous system of insects. Bacillus thuringiensis is a bacterium that produces toxins effective against certain caterpillars and is utilized as a biological control agent rather than a hormonal mimic. Monomolecular surface films function by creating a barrier that affects insect breathing, and while they impact larvae, they do not share the hormonal analog characteristic of Methoprene.