Anal papillae of culicid larvae and toxicant absorption

Abstract

The anal papillae of the mosquito larvae play an important role in the maintenance of the osmotic equilibrium of haemolymph. As absorbent surfaces, the shape of the Anal papillae control too the power of absorption of the larvae upon heavy metal salts and upon other toxics. Larvae with great sized papillae die sooner in the toxic Solutions that the larvae of species with little or reduced papillae. Separation, by ligature, of the tail of the larvae, delays death in larvae with developped papillae immersed in toxic Solutions. In general, brackish-water larvae have reduced papillae and exiges higher amounts of insecticides.