National Geographic : 1944 Feb
© National Geographic Society In a Quiet Pool, Nature Produces a Ferry Command for the Spread ofMalaria Here the female of the common malaria mosquito, Anopheles quadrimaculatus, lays her eggs singly. Insert, upper right, shows them greatly enlarged. Within two days they hatch into tiny wigglers. Eight days later the full-grown larvae (inset) become pupae (center), much likeabutterfly's chrysalis. Inanother two days, the back of the pupal shell splits and the young, full-grown mosquito emerges, ready for its nuisance raids (see Plate V).Crude oilspread onsuch pools smothers and poisons the pupae and wigglers, which must come to the surface to breathe through their tails. An effective and cheaperlarvicide isParis green.