Larvicide

Definition

An insecticide formulated to kill or disrupt the larval stage of insects, typically applied to aquatic or terrestrial breeding habitats before adults emerge. Larvicides function through contact toxicity, ingestion, growth regulation, or biological antagonism rather than targeting flying or crawling adults.

Etymology

From Latin larva (mask, ghost; later larval insect) + -cide (killer)

Example

Bacillus thuringiensis israelensis (Bti), a bacterial larvicide, is applied to standing water to kill mosquito larvae before they can transmit West Nile virus; methoprene, an insect growth regulator, disrupts pupation in container-breeding Aedes aegypti.

Synonyms

• larval insecticide

Related Terms

• adulticide
• Insect growth regulator
• vector control
• integrated vector management
• Bacillus thuringiensis
• methoprene
• breeding site
• source reduction

Usage Notes

Contrasts with adulticide, which targets mature insects. Larvicides are preferred in integrated vector management because they reduce adult populations before disease transmission begins and typically minimize non-target effects on pollinators and other beneficial insects. The term is sometimes restricted to chemical agents, though biological larvicides (bacterial, fungal, or nematode-based) are increasingly dominant in public health programs.