First report of Leptolegnia chapmanii (Peronosporomycetes: Saprolegniales) affecting mosquitoes in central Brazil

• Leptolegnia chapmanii (Saprolegniales) has been isolated widely in Central Brazil.
• All isolates cause rapid mortality of Aedes aegypti larvae, usually within 24–36 h.
• Distinctive oogonia may form in vitro but not at warm Brazilian collection sites.
• Taxonomic problems with the typification of L. chapmanii have been resolved.

Numerous isolates of an oomycete ‘fungus’, Leptolegnia chapmanii, are reported from Brazil for the first time. This aquatic pathogen was baited with Aedes aegypti sentinel larvae from stagnant, temporary bodies of water in selected locations under secondary tropical forest in and near the central Brazilian city of Goiânia and from more distant sites in the western and northern regions of the state of Goiás. Isolates were identified based on their morphological and developmental characters, comparative sequence data for the ITS and TEF loci, as well as their rapid activity against A. aegypti larvae. Taxonomic issues affecting the application of the name L. chapmanii and its typification are rectified. This study contributes to a better understanding of the presence and distribution of this oomycete in Brazil, its sequence-based identification, and of its potential as a biological agent against mosquito vectors.

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