Which of the following is NOT a class of mosquito larvicides?

• A. Oils and monomolecular films of alcohol
• B. Organophosphates
• C. Carbamates
• D. Bacterial toxins

Answer: (C)

Mosquito larvicides fall into several categories that act on larvae living in water, targeting them in different ways. Oils and monomolecular films form a thin surface layer that suffocates larvae by preventing them from breathing at the water surface. Organophosphates kill larvae by disrupting their nervous system through inhibition of acetylcholinesterase. Bacterial toxins like Bacillus thuringiensis israelensis (Bti) or Bacillus sphaericus are ingested by larvae and disrupt their gut, leading to death. Carbamates, while a broad class of insecticides used in various pest-control contexts, are not considered a standard class of mosquito larvicides in public health programs.