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15 pages, 4517 KiB

Open AccessArticle

Species Discrimination of Stomoxys Flies S. bengalensis, S. calcitrans, and S. sitiens (Diptera: Muscidae) Using Wing Geometric Morphometrics

by Tanasak Changbunjong, Tanawat Chaiphongpachara and Thekhawet Weluwanarak

Animals 2023, 13(4), 647; https://doi.org/10.3390/ani13040647 - 13 Feb 2023

Cited by 7 | Viewed by 3370

Abstract

The flies of the genus Stomoxys Geoffroy, 1762 (Diptera: Muscidae), are regarded as pests of veterinary and medical importance. In Thailand, Stomoxys calcitrans (Linnaeus, 1758) is the most abundant species and is widely distributed throughout the country. This Stomoxys species can coexist with two other morphologically similar species: Stomoxys bengalensis Picard, 1908, and Stomoxys sitiens Rondani, 1873. Hence, discriminating using morphological characteristics is difficult, especially if the specimen is damaged or loses its diagnostic characteristics. In this study, we evaluated the effectiveness of the landmark-based geometric morphometric (GM) approach to discriminate among the three Stomoxys spp.: S. bengalensis, S. calcitrans, and S. sitiens. Left-wing images of S. bengalensis (n = 120), S. calcitrans (n = 150), and S. sitiens (n = 155) were used for the GM analyses. The results of the wing shape analyses revealed that the GM approach was highly effective for discriminating three Stomoxys, with high accuracy scores ranging from 93.75% to 100%. This study adds to the evidence that landmark-based GM is an excellent alternative approach for discriminating Stomoxys species. Full article

(This article belongs to the Special Issue Parasitic Arthropods of Vertebrates)

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14 pages, 4322 KiB

Open AccessEditor’s ChoiceArticle

Species Identification of the Major Japanese Encephalitis Vectors within the Culex vishnui Subgroup (Diptera: Culicidae) in Thailand Using Geometric Morphometrics and DNA Barcoding

by Tawee Saiwichai, Sedthapong Laojun, Tanawat Chaiphongpachara and Suchada Sumruayphol

Insects 2023, 14(2), 131; https://doi.org/10.3390/insects14020131 - 26 Jan 2023

Cited by 10 | Viewed by 2998

Abstract

Japanese encephalitis (JE) is a viral infection of the brain caused by the Japanese encephalitis virus, which spreads globally, particularly in 24 countries of Southeast Asia and the Western Pacific region. In Thailand, the primary vectors of JE are Cx. pseudovishnui, Cx. tritaeniorhynchus, and Cx. vishnui of the Cx. vishnui subgroup. The morphologies of three mosquito species are extremely similar, making identification challenging. Thus, geometric morphometrics (GM) and DNA barcoding were applied for species identification. The results of cross-validation reclassification revealed that the GM technique based on wing shape analysis had relatively high potential for distinguishing Cx. pseudovishnui, Cx. tritaeniorhynchus, and Cx. vishnui (total performance = 88.34% of correctly assigned individuals). While the DNA barcoding yielded excellent results in identifying these Culex species based on the DNA barcode gap (average intraspecific genetic distance = 0.78% ± 0.39% and average interspecific genetic distance = 6.14% ± 0.79%). However, in the absence of the required facilities for DNA barcoding, GM techniques can be employed in conjunction with morphological methods to enhance the reliability of species identification. Based on the results of this study, our approach can help guide efforts to identify members of the Cx. vishnui subgroup, which will be useful for the effective vector control of JE in Thailand. Full article

(This article belongs to the Section Medical and Livestock Entomology)

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15 pages, 3839 KiB

Open AccessArticle

Evaluation of Modern Techniques for Species Identification of Lutzia Mosquitoes (Diptera: Culicidae) in Thailand: Geometric Morphometrics and DNA Barcoding

by Sedthapong Laojun, Tanasak Changbunjong and Tanawat Chaiphongpachara

Insects 2023, 14(1), 78; https://doi.org/10.3390/insects14010078 - 12 Jan 2023

Cited by 13 | Viewed by 3426

Abstract

There are four species of Lutzia mosquitoes in Thailand, including Lutzia chiangmaiensis, Lt. fuscana, Lt. halifaxii, and Lt. vorax. The accurate species identification of adult Lutzia mosquitoes based on morphological features requires many body parts, including the abdominal terga and wing. However, species identification is difficult in the case of damaged specimens when some of their morphological character is missing due to transit or gathering in the field. Thus, we evaluated the efficacy of the landmark-based geometric morphometric (GM) approach for the discrimination of Lutzia species in Thailand. In addition, DNA barcoding was also used in parallel with the GM approach to identify the species. Larvae of Lutzia were collected, raised into adults, and identified based on their morphological characteristics. The validated reclassification test results clearly demonstrated that wing shape resulted in a high level of success in identification (correct identifications ranged from 92.50% to 100%); however, based on the DNA barcoding analyses, our results showed that it was poorly effective in identifying Lt. fuscana and Lt. halifaxii based on an overlap between the intraspecific and interspecific divergence. Moreover, our survey results provide updates on the distribution of Lt. chiangmaiensis and Lt. vorax in Thailand. This research will help medical entomologists more efficiently identify mosquitoes in the genus Lutzia, resulting in more effective mosquito control and surveillance. Full article

(This article belongs to the Special Issue Mosquito: Ecology, Behavior and Molecular Biology)

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17 pages, 3183 KiB

Open AccessEditor’s ChoiceArticle

Genetic Diversity, Haplotype Relationships, and kdr Mutation of Malaria Anopheles Vectors in the Most Plasmodium knowlesi-Endemic Area of Thailand

by Tanawat Chaiphongpachara, Sedthapong Laojun, Tanasak Changbunjong, Suchada Sumruayphol, Nantana Suwandittakul, Sakultip Chookaew and Yuppayong Atta

Trop. Med. Infect. Dis. 2022, 7(12), 412; https://doi.org/10.3390/tropicalmed7120412 - 1 Dec 2022

Cited by 6 | Viewed by 3194

Abstract

Plasmodium knowlesi, a malaria parasite that occurs naturally in long-tailed macaques, pig-tailed macaques, and banded leaf monkeys, is currently regarded as the fifth of the human malaria parasites. We aimed to investigate genetic diversity based on the cytochrome c oxidase subunit I (COI) gene, detect Plasmodium parasites, and screen for the voltage-gated sodium channel (VGSC)-mutation-mediated knockdown resistance (kdr) of Anopheles mosquitoes in Ranong province, which is the most P. knowlesi-endemic area in Thailand. One hundred and fourteen Anopheles females belonging to eight species, including An. baimaii (21.05%), An. minimus s.s. (20.17%), An. epiroticus (19.30%), An. jamesii (19.30%), An. maculatus s.s. (13.16%), An. barbirostris A3 (5.26%), An. sawadwongporni (0.88%), and An. aconitus (0.88%), were caught in three geographical regions of Ranong province. None of the Anopheles mosquitoes sampled in this study were infected with Plasmodium parasites. Based on the sequence analysis of COI sequences, An. epiroticus had the highest level of nucleotide diversity (0.012), followed by An. minimus (0.011). In contrast, An. maculatus (0.002) had the lowest level of nucleotide diversity. The Fu’s Fs and Tajima’s D values of the Anopheles species in Ranong were all negative, except the Tajima’s D values of An. minimus (0.077). Screening of VGSC sequences showed no presence of the kdr mutation of Anopheles mosquitoes. Our results could be used to further select effective techniques for controlling Anopheles populations in Thailand’s most P. knowlesi-endemic area. Full article

(This article belongs to the Special Issue Emerging Vector-Borne Diseases and Public Health Challenges)

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15 pages, 2336 KiB

Open AccessArticle

Wing Phenotypic Variation among Stomoxys calcitrans (Diptera: Muscidae) Populations in Thailand

by Tanawat Chaiphongpachara, Gerard Duvallet and Tanasak Changbunjong

Insects 2022, 13(5), 405; https://doi.org/10.3390/insects13050405 - 23 Apr 2022

Cited by 10 | Viewed by 3874

Abstract

Stomoxys calcitrans (Linnaeus, 1758) (Diptera: Muscidae) is a cosmopolitan hematophagous ectoparasite of veterinary and medical importance. It is an important mechanical vector of several animal pathogens and can cause significant economic losses. However, the morphological variation of this species remains unknown. This study aimed to investigate the phenotypic variation in the wing size and shape of S. calcitrans populations in Thailand based on a landmark-based geometric morphometric approach. Specimens were collected from five populations in five geographical regions in Thailand. A total of 490 left wings of S. calcitrans (245 female and 245 male individuals) were used for geometric morphometric analysis. Wing size differences were detected between some populations of S. calcitrans, whereas wing shape differences were found among populations. Therefore, the phenotypic variation in S. calcitrans populations indicated that these populations are adaptive responses to local environmental pressures, suggesting the presence of phenotypic plasticity in this species. Full article

(This article belongs to the Special Issue Biology, Ecology and Control of Synanthropic Flies)

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12 pages, 16227 KiB

Open AccessArticle

Species Discrimination of Three Odontomachus (Formicidae: Ponerinae) Species in Thailand Using Outline Morphometrics

by Yudthana Samung, Tanawat Chaiphongpachara, Jiraporn Ruangsittichai, Patchara Sriwichai, Anon Phayakkaphon, Weeyawat Jaitrong, Jean-Pierre Dujardin and Suchada Sumruayphol

Insects 2022, 13(3), 287; https://doi.org/10.3390/insects13030287 - 14 Mar 2022

Cited by 7 | Viewed by 4026

Abstract

All members of the ant genus Odontomachus Latreille, 1804 are venomous ants. Four species in this genus have been identified from Thailand: Odontomachus latidens Mayr, 1867; O. monticola Emery, 1892; O. rixosus Smith, 1757; and O. simillimus Smith, 1758. The three latter species are available and have been used for an outline morphometric study. They display similar morphology, which makes their distinction very difficult except for highly qualified individuals. A total of 80 worker specimens were studied, exploring the contour shapes of their head and pronotum as possible taxonomic characters. The size of each body part was estimated determining the contour perimeter, the values for which were largely overlapping between O. rixosus and O. simillimus; most O. monticola specimens exhibited a significantly larger size. In contrast to the size, each contour shape of the head or pronotum established O. rixosus as the most distinct species. An exploratory data analysis disclosed the higher taxonomic signal of the head contour relative to the pronotum one. The scores obtained for validated reclassification were much better for the head (99%) than for the pronotum (82%). This study supports outline morphometrics of the head as a promising approach to contribute to the morphological identification of ant species, at least for monomorphic workers. Full article

(This article belongs to the Section Other Arthropods and General Topics)

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13 pages, 2724 KiB

Open AccessArticle

Landmark Data to Distinguish and Identify Morphologically Close Tabanus spp. (Diptera: Tabanidae)

by Tanasak Changbunjong, Nutnicha Prakaikowit, Photchanun Maneephan, Tipparat Kaewwiset, Thekhawet Weluwanarak, Tanawat Chaiphongpachara and Jean-Pierre Dujardin

Insects 2021, 12(11), 974; https://doi.org/10.3390/insects12110974 - 28 Oct 2021

Cited by 23 | Viewed by 5735

Abstract

Tabanus spp., also known as horse flies (Diptera: Tabanidae), are important vectors of several animal pathogens. Adult females of Tabanus megalops and Tabanus striatus, which are members of the T. striatus complex, are morphologically similar and hence difficult to distinguish using morphological characteristics. In addition, molecular identification by DNA barcoding is also unable to distinguish these species. These two species can occur sympatrically with Tabanus rubidus, which is morphologically similar to T. megalops and T. striatus. Wing geometric morphometrics has been widely used in various insects to distinguish morphologically similar species. This study explored the effectiveness of landmark-based geometrics at distinguishing and identifying T. megalops, T. rubidus, and T. striatus in Thailand. Specimens were collected from different geographical regions of Thailand, and only unambiguously identified specimens were used for geometric morphometric analyses. Left wings of females of T. megalops (n = 160), T. rubidus (n = 165), and T. striatus (n = 85) were photographed, and 22 wing landmarks were used for the analysis. Wing shape was able to distinguish among species with high accuracy scores, ranging from 94.38% to 99.39%. We showed that morphologically very close species of Tabanus can be reliably distinguished by the geometry of their wing venation, and we showed how our experimental material could be used as a reference to tentatively identify new field collected specimens. Full article

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