Which term describes a substance used to control tick populations?

The term that describes a substance specifically used to control tick populations is "acaricide." Acaricides are designed to target arachnids, such as ticks and mites. This is important because ticks belong to the arachnid class, which differentiates them from insects. Using acaricides effectively interrupts the life cycle of ticks, helping to reduce their population and minimize the risk of tick-borne diseases.

Adulticides, while effective against adult insects, do not specifically target ticks. Insecticides are formulated to control insects, which excludes arachnids like ticks. Larvicides are designed to target the larval stage of insects and would not be effective against ticks at any stage of their life cycle. Therefore, the specificity of acaricides in addressing tick populations makes it the correct choice in this context.