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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Emerging Pests and Pathogens Research » Research » Publications at this Location » Publication #330288
Research Project: Management and Biology of Arthropod Pests and Arthropod-borne Plant Pathogens

Location: Emerging Pests and Pathogens Research

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

Author
item MONTALVA, C. - Federal University Of Goias
item DOS SANTOS, K. - Federal University Of Goias
item COLLIER, K. - Federal University Of Goias
item FERNANDES,, EKK - Federal University Of Goias
item LUZ, C. - Federal University Of Goias
item Humber, Richard

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2016
Publication Date: 3/23/2016
Citation: Montalva, C., Dos Santos, K., Collier, K., Fernandes, E., Luz, C., Humber, R.A. 2016. First report of Leptolegnia chapmanii (Peronosporomycetes: Saprolegniales) affecting mosquitoes in Central Brazil. Journal of Invertebrate Pathology. 136:109-116.

Interpretive Summary: Leptolegnia chapmanii is widely known but an understudied fungal pathogen of mosquitoes that can kill larvae within 24-36 hours, long before an active infection is established inside the host’s body. It is also an extremely rare example of a fungal pathogen able to infect either through the gut after ingestion of the encysted spores or by penetrating the host exoskeleton. L. chapmanii has been known from the United States and a single collection from Argentina, but surveys in central Brazil for mosquito-pathogenic fungi found that it is unexpectedly widely distributed and common at almost every site that was sampled throughout the state of Goiás. New information about where and how to collect this fungus in the field, and how to isolate pure cultures were developed, The identification of these Brazilian collections of L. chapmanii was complicated by nomenclatural issues involving the absence of any taxonomic type material that could be used for comparison and verification and by the near absence of the one spore type that is the most diagnostic for this species (for which no molecular characters are available); these issues are resolved here. These findings should make L. chapmanii much more attractive as a biological control agent for use against a wide range of mosquito vectors of major diseases in tropical and temperate regions of the world.

Technical Abstract: 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 forests 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 as well as their rapid activity against A. aegypti larvae. Taxonomic issues affecting the application of the name Leptolegnia chapmanii and its typification are discussed. This study contributes to a better understanding of the geographical distribution and occurrence of this important entomopathogen and of its potential as a biological agent against mosquito vectors.