DNA barcoding and wing morphometrics to distinguish three Aedes vectors in Thailand

Suchada Sumruayphol a , Chamnarn Apiwathnasorn a , Jiraporn Ruangsittichai a ,
Patchara Sriwichai a , Siriluck Attrapadung a , Yudthana Samung a , Jean-Pierre Dujardin b,∗

a

Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand

b

Unité Mixte de Recherche 177-Interactions Hôte-Vecteur-Parasite-Enrironnement dans les Maladies Tropicales Négligées dues aux Trypanosomatidés,
Centre International de Recherches Agronomiques pour le Développement (CIRAD), Institut de Recherches pour le Développement (IRD), Campus
international de Baillarguet, Montpellier, France

a b s t r a c t

Aedes aegypti (Diptera: Culicidae) (L.), Ae. albopictus (Skuse), and Ae. scutellaris (Walker) are important mosquito vectors of dengue and chikungunya viruses. They are morphologically similar and sympatric in some parts of their distribution; therefore, there is a risk of incorrect morphological identification.
Any confusion could have a negative impact on epidemiological studies or control strategies. Therefore, we explored two modern tools to supplement current morphological identification: DNA barcoding and geometric morphometric analyses. Field larvae were reared to adults and carefully classified based on morphological traits. The genetic analysis was based on the 658 bp each of 30 COI sequences. Some Culex spp., Mansonia bonneae, were included as outgroups, and inclusion of a few other Aedes spp. facilitated phylogenetic inference of the relationship between Ae. albopictus and Ae. scutellaris. The two species were separated by an average interspecific divergence of 0.123 (0.119–0.127). Morphometric examination included landmark- (392 specimens) and outline-based (317 specimens) techniques. The shape of the wing showed different discriminating power based on sex and digitizing technique. This is the first time that Ae. scutellaris and Ae. albopictus have been compared using these two techniques. We confirm that these morphologically close species are valid, and that geometric morphometrics can considerably increase the reliability of morphological identification.

Landmark and outline-based geometric morphometrics analysis of three Stomoxys flies (Diptera: Muscidae)

Tanasak Changbunjong 1,2 , Suchada Sumruayphol 3 , Thekhawet Weluwanarak 2 , Jiraporn Ruangsittichai 3 and
Jean-Pierre Dujardin 4
1
Department of Pre-clinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom,
Thailand;
2
The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science,
Mahidol University, Nakhon Pathom, Thailand;
3
Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand;
4
Institut de Recherches pour le Développement, Campus International de Baillarguet, Montpellier, France

Folia Parasitologica 2016, 63: 037
doi: 10.14411/fp.2016.037

Abstract:

Adult flies of the genus Stomoxys Geoffroy, 1762 (Diptera: Muscidae), especially S. pullus Austen, 1909, S. uruma Shinonaga et Kano, 1966 and S. indicus Picard, 1908, are morphologically similar and sometimes difficult to distinguish when using external
morphological characteristics. These species may act as vectors and/or potential vectors of many pathogens (virus, bacteria and protozoa). Their correct identification is important to target the vectors involved in the transmission of the pathogens and also helps in the fly control program.The aim of the present study was to distinguish three species which are difficult to separate using traditional diagnostic characters for species of Stomoxys such as colour patterns and body proportions. Modern morphometrics, both landmark and outline-based, was used to access wing geometry of S. pullus, S. uruma and S. indicus. A total of 198 and 190 wing pictures were analysed for landmark- and outline-based approaches, respectively. Wing shape was able to separate species and sexes of the three Stomoxys flies with highly significant difference of Mahalanobis distances. The cross-validated classification scores ranged from 76% to 100% for landmark and 77% to 96% for outline-based morphometrics. The geometry of wing features appears to be a very useful, low-cost tool to distinguish among the vectors S. pullus, S. uruma and S. indicus. Keywords: muscidae, landmarks, outlines, Stomoxys pullus, Stomoxys uruma, Stomoxys indicus.

Wing geometry of Phlebotomus stantoni and Sergentomyia hodgsoni from different geographical locations in Thailand

Suchada Sumruayphol a, *, Boonruam Chittsamart a , Raxsina Polseela b,c ,
Patchara Sriwichai a , Yudthana Samung a , Chamnarn Apiwathnasorn a ,
Jean-Pierre Dujardin d

a

Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, 10400 Bangkok, Thailand

b

Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, 65000 Phitsanulok, Thailand

c

Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University, 65000 Phitsanulok, Thailand

d

UMR17 IRD–CIRAD INTERTRYP TA A 17/G, Campus international de Baillarguet, 34398 Montpellier cedex 5, France

http://dx.doi.org/10.1016/j.crvi.2016.10.002

Geographic populations of the two main sandflies genera present in Thailand were studied for species and population identification. Size and shape of Phlebotomus stantoni and Sergentomyia hodgsoni from different island and mainland locations were examined by landmark-based geometric morphometrics. Intraspecific and interspecific wing comparison was carried out based on 12 anatomical landmarks. The wing centroid size of P. stantoni was generally larger than that of S. hodgsoni. Within both species, wings from the continent were significantly larger than those from island populations. Size variation could be significant between geographic locations, but could also overlap between genera. The wing venation geometry showed non-overlapping differences between two species. The within-species variation of geometric shape between different geographical locations was highly significant, but it could not interfere with the interspecies difference. The lack of species overlapping in shape, and the high discrimination between geographic populations, make geometric shape a promising character for future taxonomic and epidemiological studies.

ß 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Outline-based morphometrics, an overlooked… [Infect Genet Evol. 2014] – PubMed – NCBI

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Rhodnius wing, an internal outline discriminating cryptic species

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