Mosquito wing measurements separate potential West Nile vectors: a morphometric study of three Culex species

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Paige Robinson (Creator)
Institution
Western Carolina University (WCU )
Web Site: http://library.wcu.edu/

Abstract: Culex interrogator (Dyar and Knab), Culex restuans (Theobald), and Culex quinquefasciatus (Say) are three morphologically similar species with syntopic distributions. Culex restuans and Cx. quinquefasciatus are known West Nile vectors, while Cx. interrogator has not been reported to transmit this virus. Recent range expansions of Cx. interrogator has increased the need to identify morphological characters that can differentiate between these three similar mosquito species. Accurate identification is crucial to aid with West Nile virus surveillance efforts and potentially prevent misappropriation of resources or unnecessary interventions (e.g. pesticide application). The four morphological characteristics used in this study include the length and width of the whole wing, the length of the R2 cell, and the length of the R2+3 vein. We evaluated both intraindividual and interindividual differences in the three species. In conjunction with prior research (Shin et al., 2016) these characters are useful for accurate discrimination of Cx. interrogator from Cx. restuans and Cx. quinquefasciatus. Preliminary results suggest that wing length or an index can be used to distinguish Cx. interrogator from Cx. restuans and Cx. quinquefasciatus. An index comparing the ratios of wing measurements can separate 92% (n=25, 95% CI: 74.0-99.0%) of the Cx. restuans and Cx. quinquefasciatus. However, some wing character measurements overlap between species and investigators may need to rely on either different morphometric measurements or molecular methods to confirm results. When taken together, these measurements accurately identify 94.9% (n=39, 95% CI: 82.7%-99.4%) of the three species. The current species identification is based on morphology alone (non-wing characters), and will be confirmed by a species-specific rDNA PCR assay which produces amplicon size polymorphisms visible by gel electrophoresis (in progress).

Additional Information

Publication
Other
Language: English
Date: 2018

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