Ammonia transport by terrestrial and aquatic insects

Ammonia, an end product from amino acid and nucleic acid metabolism, is highly toxic for most animals. This review will provide an update on nitrogen metabolism in terrestrial and aquatic insects with emphasis on ammonia generation and transport.Aspects that will be discussed include metabolic pathways of nitrogenous compounds, the origin of ammonia and other nitrogenous waste products, ammonia toxicity, putative ammonia transporters as well as ammonia transport processes known in insects. Ammonia transport mechanisms in the mosquito Aedes aegypti, the tobacco hornworm Manduca sexta and the locust Schistocerca gregaria will be discussed in detail while providing additional, novel data.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We summarize and update the current knowledge on nitrogen excretion in insects with emphasis on ammonia transport. ► Information on metabolic pathways of nitrogenous compounds and mechanisms of excretion are provided. ► The role of Rh-proteins and other ammonia transporters in insects are discussed in detail. ► Examples of ammonia excretion strategies for Aedes aegypti, Manduca sexta and Schistocerca gregaria are given.