Diversity of insect-specific viruses in Culex mosquitoes from Papua New Guinea.
10 affiliations
- 1CSIRO, Australian Centre for Disease Preparedness, Geelong, 3220, Victoria, Australia. [email protected].
- 2School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, 2678, New South Wales, Australia. [email protected].
- 3CSIRO, Australian Centre for Disease Preparedness, Geelong, 3220, Victoria, Australia.
- 4Papua New Guinea Institute of Medical Research, Port Moresby, Papua New Guinea.
- 5School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, 2678, New South Wales, Australia.
- 6Gulbali Institute, Charles Sturt University, Wagga Wagga, 2678, New South Wales, Australia.
- 7School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Wagga Wagga, 2650, New South Wales, Australia.
- 8Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, 4878, Queensland, Australia.
- 9Holsworth Biomedical Research Centre, Department of Rural Clinical Sciences, La Trobe Rural Health School, La Trobe University, Bendigo, 3550, Victoria, Australia.
- 10CSIRO, Australian Centre for Disease Preparedness, Geelong, 3220, Victoria, Australia. [email protected].
Abstract
Insect-specific viruses (ISVs) are integral components of mosquito viromes, influencing virus evolution, vector competence, and arbovirus ecology. Papua New Guinea (PNG) is a region of exceptional biodiversity, yet ISVs in local mosquito populations remain poorly characterized. Here, we present the first comprehensive metagenomic survey of ISVs in Culex mosquitoes collected across five provinces of PNG between 2019 and 2021. Using unbiased shotgun metagenomic sequencing, 13,871 female Culex mosquitoes representing five species were analyzed across 86 samples. Approximately 1.6 billion paired-end reads were generated, yielding ∼20 million viral read pairs. Overall, 231 viral species representing 38 viral families were detected. Of these, 120 were ISV species spanning 25 viral families, and ISVs accounted for 93.8% of species-assigned viral reads, with RNA viruses predominating. The most abundant families included Partitiviridae, Birnaviridae, Rhabdoviridae, and Iflaviridae. Approximately 40% of viral reads corresponded to viruses that are not currently assigned to recognized ICTV families. More than 150 complete viral genomes or genome segments were recovered, including divergent sequences that share <90% amino acid identity with known references. Phylogenetic analyses revealed several divergent viral lineages across major ISV groups. Within the Partitiviridae, previously unrecognized RNA-dependent RNA polymerase (RdRP)-capsid pairings enabled reconstruction of complete genome architectures for Broome partiti-like virus 1 and Sonnbo virus for the first time, together with additional divergent partitivirus lineages. Cambodia Culex birnavirus sequences from PNG, clustered within the known lineage but formed a distinct regional clade. Rhabdovirus analyses identified host-restricted lineages, including Culex tritaeniorhynchus rhabdovirus-like sequences confined to Culex annulirostris. Within the Iflaviridae, several viruses were detected for the first time in PNG. Hubei virga-like virus 2 was the most abundant ISV detected and formed a PNG-specific clade, suggesting local diversification. ISVs were detected in both blood-fed and unfed mosquitoes, indicating that they are stable constituents of the mosquito virome. Multiple viral species from the same family were detected within pooled samples, consistent with either co-infection of individual mosquitoes or heterogeneous infections among pooled individuals. Overall, this study reveals a diverse ISV landscape in PNG Culex mosquitoes, expanding the known geographic range and genetic diversity of multiple viral groups and providing a baseline for future investigations into ISV ecology and evolution in the Indo-Pacific region and mosquito-virus interactions globally.
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BibTeX
@article{danthanarayana2026diversity,
title = {{Diversity of insect-specific viruses in Culex mosquitoes from Papua New Guinea.}},
author = {Nayomi Danthanarayana and James O'Dwyer and Joelyn Goi and Shaylie Latimore and Vittoria Stevens and Martin Pal and Brain P McSharry and Marta Hernandez-Jover and William Pomat and Stephan Karl and Justin A Roby and Jade K Forwood and Matthew J Neave and David T Williams},
journal = {Virology journal},
year = {2026},
month = jul,
doi = {10.1186/s12985-026-03258-3},
url = {https://europepmc.org/article/MED/42907919},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Diversity of insect-specific viruses in Culex mosquitoes from Papua New Guinea.
AU - Nayomi Danthanarayana
AU - James O'Dwyer
AU - Joelyn Goi
AU - Shaylie Latimore
AU - Vittoria Stevens
AU - Martin Pal
AU - Brain P McSharry
AU - Marta Hernandez-Jover
AU - William Pomat
AU - Stephan Karl
AU - Justin A Roby
AU - Jade K Forwood
AU - Matthew J Neave
AU - David T Williams
PY - 2026
DA - 2026/07/01
JO - Virology journal
DO - 10.1186/s12985-026-03258-3
UR - https://europepmc.org/article/MED/42907919
AB - Insect-specific viruses (ISVs) are integral components of mosquito viromes, influencing virus evolution, vector competence, and arbovirus ecology. Papua New Guinea (PNG) is a region of exceptional biodiversity, yet ISVs in local mosquito populations remain poorly characterized. Here, we present the first comprehensive metagenomic survey of ISVs in Culex mosquitoes collected across five provinces of PNG between 2019 and 2021. Using unbiased shotgun metagenomic sequencing, 13,871 female Culex mosquitoes representing five species were analyzed across 86 samples. Approximately 1.6 billion paired-end reads were generated, yielding ∼20 million viral read pairs. Overall, 231 viral species representing 38 viral families were detected. Of these, 120 were ISV species spanning 25 viral families, and ISVs accounted for 93.8% of species-assigned viral reads, with RNA viruses predominating. The most abundant families included Partitiviridae, Birnaviridae, Rhabdoviridae, and Iflaviridae. Approximately 40% of viral reads corresponded to viruses that are not currently assigned to recognized ICTV families. More than 150 complete viral genomes or genome segments were recovered, including divergent sequences that share <90% amino acid identity with known references. Phylogenetic analyses revealed several divergent viral lineages across major ISV groups. Within the Partitiviridae, previously unrecognized RNA-dependent RNA polymerase (RdRP)-capsid pairings enabled reconstruction of complete genome architectures for Broome partiti-like virus 1 and Sonnbo virus for the first time, together with additional divergent partitivirus lineages. Cambodia Culex birnavirus sequences from PNG, clustered within the known lineage but formed a distinct regional clade. Rhabdovirus analyses identified host-restricted lineages, including Culex tritaeniorhynchus rhabdovirus-like sequences confined to Culex annulirostris. Within the Iflaviridae, several viruses were detected for the first time in PNG. Hubei virga-like virus 2 was the most abundant ISV detected and formed a PNG-specific clade, suggesting local diversification. ISVs were detected in both blood-fed and unfed mosquitoes, indicating that they are stable constituents of the mosquito virome. Multiple viral species from the same family were detected within pooled samples, consistent with either co-infection of individual mosquitoes or heterogeneous infections among pooled individuals. Overall, this study reveals a diverse ISV landscape in PNG Culex mosquitoes, expanding the known geographic range and genetic diversity of multiple viral groups and providing a baseline for future investigations into ISV ecology and evolution in the Indo-Pacific region and mosquito-virus interactions globally.
SN - 1743-422X
ER -