Seasonal dynamics and molecular differentiation of three natural Anopheles species (Diptera: Culicidae) of the Maculatus group (Neocellia series) in malaria hotspot villages of Thailand

Suchada Sumruayphol,Jetsumon Sattabongkot,Tanawat Chaiphongpachara,Liwang Cui,Patchara Sriwichai,Daibin Zhong,Jiraporn Ruangsittichai,Yudthana Samung

doi:10.1186/s13071-020-04452-0

Abstract

BackgroundAnopheles sawadwongporni Rattanarithikul & Green, Anopheles maculatus Theobald and Anopheles pseudowillmori (Theobald) of the Anopheles maculatus group (Diptera: Culicidae) are recognized as potential malaria vectors in many countries from the Indian subcontinent through Southeast Asia to Taiwan. A number of malaria vectors in malaria hotspot areas along the Thai-Myanmar border belong to this complex. However, the species distribution and dynamic trends remain understudied in this malaria endemic region.MethodsMosquitoes of the Maculatus group were collected using CDC light traps every other week from four villages in Tha Song Yang District, Tak Province, Thailand from January to December 2015. Adult female mosquitoes were morphologically identified on site using taxonomic keys. Molecular species identification was performed by multiplex PCR based on the internal transcribed spacer 2 (ITS2) region of ribosomal DNA (rDNA) and sequencing of the cox1 gene at a DNA barcoding region in a subset of 29 specimens.ResultsA total of 1328 An. maculatus (sensu lato) female mosquitoes were captured with An. maculatus, An. sawadwongporni and An. pseudowilmori accounting for 75.2, 22.1 and 2.7% respectively. The field captured mosquitoes of the Maculatus group were most abundant in the wet season and had a preferred distribution in villages at higher elevations. The phylogenetic relationships of 29 cox1 sequences showed a clear-cut separation of the three member species of the Maculatus group, with the An. pseudowillmori cluster being separated from An. sawadwongporni and An. maculatus.ConclusionsThis study provides updated information for the species composition, seasonal dynamics and microgeographical distribution of the Maculatus group in malaria-endemic areas of western Thailand. This information can be used to guide the planning and implementation of mosquito control measures in the pursuance of malaria transmission.Graphical

Highlights

Anopheles sawadwongporni Rattanarithikul & Green, Anopheles maculatus Theobald and Anopheles pseudowillmori (Theobald) of the Anopheles maculatus group (Diptera: Culicidae) are recognized as potential malaria vectors in many countries from the Indian subcontinent through Southeast Asia to Taiwan
The monthly dynamics of the Maculatus group captured from the four villages showed two peaks during the rainy season with the main peak occurring in August to September (Fig. 2a)
KN village had the highest abundance of the Maculatus group with the highest proportion of An. maculatus 58.6% (778/1328), which peaked in August

Summary

Introduction

Anopheles sawadwongporni Rattanarithikul & Green, Anopheles maculatus Theobald and Anopheles pseudowillmori (Theobald) of the Anopheles maculatus group (Diptera: Culicidae) are recognized as potential malaria vectors in many countries from the Indian subcontinent through Southeast Asia to Taiwan. A number of malaria vectors in malaria hotspot areas along the Thai-Myanmar border belong to this complex. Anopheles mosquitoes (Diptera: Culicidae) are the sole vectors of malaria. 70 species of formally recognized Anopheles are human malaria vectors and 40 species are dominant malaria vectors [4, 5]. Different species of Anopheles mosquitoes play different roles in malaria transmission in each area. The first key for the control of malaria vectors is the knowledge of the correct vector species that can transmit malaria. The collection of adult mosquitoes in the field using traps often causes damage to the specimens, resulting misidentification [8]

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