What distinguishes larvicides from adulticides in mosquito control, and provide an example of each.

• A. Larvicides target immature aquatic stages; adulticides target flying adults; examples: Bacillus thuringiensis israelensis (Bti) and pyrethroid ULV formulations.
• B. Larvicides target plants; adulticides target animals; examples: Bti and pyrethroids.
• C. Larvicides target adults; adulticides target eggs; examples: methoprene and malathion.
• D. Larvicides target leaves; adulticides target seeds; examples: Bti and permethrin.

Answer: (A)

The essential idea is that mosquito control products are chosen for the life stage they target. Larvicides kill the immature aquatic stages (larvae) that live in standing water, preventing them from maturing into biting adults. An example is Bacillus thuringiensis israelensis (Bti), a microbial larvicide whose toxins kill larvae when they feed in water. In contrast, adulticides kill the flying adult mosquitoes; a common example is pyrethroid formulations used in ultra-low-volume (ULV) spraying to contact and kill adults in the air or on surfaces. This pairing makes the statement correct because it matches the correct life-stage targets with representative products. The other options misstate what larvicides or adulticides act upon (plants, seeds, leaves, eggs) and mix up the roles of the products.