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

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.

Outline-based geometric morphometric analysis to identify two Anopheles and three Culex mosquitoes in Thailand

“…Shape analysis has demonstrated differences between species in all cells, reflecting the effectiveness of the method for discrimination between both mosquitoes. In accordance with previous research, an outline-based GM approach has proven effective in species identification of many arthropods, such as mosquitoes (Sumruayphol et al 2016), trombiculid mites within the genus Walchia (Sungvornyothin et al 2018), stomoxys flies (Changbunjong et al 2016), and tsetse flies (Kaba et al 2017). These results suggest that each outline on the same wing of a mosquito has the power to discriminate each species of mosquitoes differently.…”

Sexual behaviour and morphological variation in the millipede Megaphyllum bosniense (Verhoeff, 1897)

“…To analyse shape and size of antennae, walking legs, head, and gonopods (promeres, opisthomeres), geometric morphometrics was applied as a method widely used in animal studies (Kaliontzopoulou et al, 2007;McPeek et al, 2008McPeek et al, , 2009Wojcieszek and Simmons, 2011;Brusatte et al, 2012;Richmond, 2014;Changbunjong et al, 2016;Sasakawa, 2016). For these analyses, we used: 1) the antennae in 56 males (41 mated and 15 non-mated, further presented as mated/non-mated) and 57 females (42/15); 2) the walking legs from the 25 th body ring in 57 males (42/15) and 56 females (41/15); 3) the head in 57 males (42/15) and 54 females (40/14); and 4) the promeres of 57 males (42/15) and 5) opisthomeres of 56 males (42/14).…”

Identifying Chagas disease vectors using Elliptic Fourier Descriptors of body contour: A case for the cryptic dimidiata complex

“…The use of EFDs has been little explored, though on several occasions it has demonstrated its ability to discriminate among even closely related species [65,66]. Even more, some studies with triatomines [27,53] and other insects of medical importance [27,67,68,69] have demonstrated the usefulness of these methods for species recognition in this genus.…”