Which type of pesticide is specifically used to kill mollusks, such as zebra mussels?

The correct answer is molluscicide because this type of pesticide is formulated specifically to target and kill mollusks, including harmful invasive species such as zebra mussels. Molluscicides contain active ingredients that affect the biological processes of these organisms, disrupting their life cycles and ultimately leading to their death. This specificity is crucial in managing aquatic ecosystems where the presence of invasive mollusks can cause significant ecological and economic damage.

In contrast, acaricides are designed to control mites and ticks, herbicides are used to manage plant growth, and fungicides target fungal organisms. Each of these pesticide types serves distinct purposes and is formulated based on the biology and physiology of the pests they are intended to manage, which is why they do not effectively deal with mollusks. Understanding the specific targeting of each pesticide type is essential for effective pest management and environmental protection.