Diptera vectors of avian haemosporidians: With emphasis on tropical regions

Abstract

Haemosporidian parasites are a globally distributed group of protists that infects many species of vertebrates (amphibians, reptiles, birds, and mammals) and are transmitted by bloodsucking dipteran insects (Insecta: Diptera). Although significant progress has been made toward understanding the details of the life cycle of these parasites, our current knowledge about patterns of development of different haemosporidian species in vectors is insufficient. Experimental and methodological studies with vectors and patterns of transmission of wildlife haemosporidian parasites are uncommon. Little is known about the effects of avian haemosporidian infections on vectors, and detailed experimental and field studies on vector competence are critical. These represent significant barriers to better understanding the epizootiology of avian haemosporidians and the evolutionary biology of this diverse group of parasites. This chapter introduces the Diptera families that are commonly associated with the transmission of avian haemosporidian parasites and describes the sexual and sporogonic processes that ultimately produce sporozoites, the infective stage to vertebrate hosts. A brief historical perspective of haemosporidian vector studies is also outlined, as well as an overview of methodological and experimental procedures conducted with different Diptera species during the past 8 years. Furthermore, the chapter explores how the use of molecular methods has contributed to the understanding of vector ecology and biodiversity, highlighting tropical vectors. Finally, we propose directions for further research aiming to improve our knowledge about vector-haemosporidian parasite interactions in the tropics.