Which synthetic insecticide is known for its name ending in 'Thrin'?

Esfenvalerate is recognized as a synthetic pyrethroid insecticide, and its name indeed ends with 'Thrin'. Synthetic pyrethroids, such as esfenvalerate, are formulated to mimic the natural insecticidal properties found in pyrethrins, which are extracted from chrysanthemum flowers. The 'Thrin' suffix is commonly associated with this class of chemicals, which are effective against a broad spectrum of pests due to their ability to disrupt the normal functioning of the nervous system in insects.

The other choices reflect different classes or types of pest control substances. For instance, Hydramethylon is not specifically known as a pyrethroid, and Dursban is the trade name for chlorpyrifos, an organophosphate insecticide, which does not fall under the 'Thrin' nomenclature. Hexaflumuron is a chitin synthesis inhibitor and also does not fit the naming pattern associated with pyrethroids. Thus, esfenvalerate stands out as the only synthetic insecticide option that conforms to the identification criteria of ending in 'Thrin'.