What is a substance used specifically to kill insect larvae?

A substance that is specifically designed to kill insect larvae is known as a larvicide. This term derives from "larvae," which refers to the juvenile form of insects before they metamorphose into adults. Larvicides are typically used in various pest management strategies to control pests like mosquitoes and other insects that reproduce in aquatic environments. By targeting the larval stage, these substances effectively break the life cycle of the insects, reducing their populations before they mature and become more challenging to control.

The other options refer to substances targeting different types of pests. Miticides are used to kill mites, which are arachnids and not insects. Nematicides are designed to control nematodes, which are microscopic worms that can damage plant roots. Molluscicides target mollusks, such as slugs and snails. Each of these substances serves a specific purpose in pest management, focusing on different types of pests rather than specifically addressing insect larvae.