Morphometric Analysis of Longipalpis (Diptera: Psychodidae) Complex Populations in Mato Grosso do Sul, Brazil

Abstract

Owing to the existence of cryptic species that are difficult to distinguish morphologically, the search for new taxonomic characters and methods for identifying and classifying sand flies continues. Lutzomyia longipalpis (Lutz & Neiva, 1912) and Lutzomyia cruzi (Mangabeira, 1938) (Diptera: Psychodidae) are two such species that occur in sympatry in some regions of Mato Grosso do Sul State (MS). Twenty females and twenty males from each of the five populations of Lu. longipalpis and one population of Lu. cruzi from MS were examined. An outlying population of Lu. longipalpis from Estrela de Alagoas, State of Alagoas, was used to compare the degree of divergence among the groups in MS. Specimens were cleared, mounted on slides, identified, and measured using LAS-Leica. The principal component analysis of morphometric characters showed a high degree of variation among females, while males varied to a lower degree. The populations of Alagoas and Miranda demonstrated the greatest variation. The first region, Alagoas, is geographically distant from the others and occurs under distinctly different ecological conditions, which likely accounts for the variation. Further studies should be made to elucidate the factors that contribute to the differences found between the populations of MS.

Host plant affects morphometric variation ofDiaphorina citri(Hemiptera: Liviidae)

“…A newer approach, geometric morphometric analysis, provides a mechanism to evaluate shape independent of size through the use of landmarks on two- and three-dimensional surfaces (Rohlf & Slice, 1990; Bookstein, 1991; Bookstein, 1996; Rohlf & Marcus, 1993; Dryden & Mardia, 1998). Geometric morphometric analysis has provided insight into patterns of morphological variation associated with Musca domestica L. wild populations and laboratory colonies (Ludoški et al, 2014), wild sandfly populations (Santos et al, 2015), the discrimination of four species of Culex mosquitoes (Laurito, Almirón & Ludueña-Almeida, 2015) and synonymy of two Bactrocera species (Schutze et al, 2015). Geometric morphometric analysis has also been instrumental in visualizing and comparing morphometric variation in relation to factors such as competition of sympatric species (Adams & Rohlf, 2000), environmental variables such as temperature and rainfall (Benítez et al, 2014), temporal variation (Drake & Klingenberg, 2008), and geographic variation (Lashkari et al, 2013).…”

The current status of the Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) species complex

“…longipalpis species complex is accepted and has raised the prospect of assigning valid taxonomic names to its included species ( Brandão-Filho et al 2009 ). Although a few morphologic studies have shown differences among some populations (de la Riva et al 2001 , Santos et al 2015 ), no discrete anatomical attribute has proven to be reliably diagnostic and extensively employed. The exact number of sibling species in the Lu.…”

The role of wing geometric morphometrics in the identification of sandflies within the subgenus Lutzomyia

“…Other studies have also been unable to separate the sibling species within this group. Santos et al (2015) found no significant morphometric differences when comparing L. longipalpis and L. cruzi populations from the Brazilian state of Mato Grosso do Sul. In addition, Pinto et al (2015) demonstrated that these species are highly related and present low genetic divergence.…”

“…Santos et al . () found no significant morphometric differences when comparing L. longipalpis and L. cruzi populations from the Brazilian state of Mato Grosso do Sul. In addition, Pinto et al .…”

“…Vigoder et al (2010) found evidence that love songs among L. cruzi males are similar to those produced by some L. longipalpis populations. Future studies to quantify morphometric variations in other structures, such as the spermathecae or palp (Dujardin et al, 1999;Cazorla & Acosta, 2003) through analyses of the contours of these structures (Dujardin et al, 2014) and genetic variations between species based on different molecular markers and including different L. longipalpis populations (Santos et al, 2015) may help to differentiate between the sibling species in this group.…”