DNA barcode assessment and population structure of aphidophagous hoverfly Sphaerophoria scripta: Implications for conservation biological control

Abstract

With the advent of integrated pest management, the conservation of indigenous populations of natural enemies of pest species has become a relevant practice, necessitating the accurate identification of beneficial species and the inspection of evolutionary mechanisms affecting the long‐time persistence of their populations. The long hoverfly, Sphaerophoria scripta, represents one of the most potent aphidophagous control agents due to a worldwide distribution and a favorable constellation of biological traits. Therefore, we assessed five European S. scripta populations by combining molecular (cytochrome c oxidase subunit I‐ COI, internal transcribed spacer 2‐ ITS2, and allozyme loci) and morphological (wing size and shape) characters. COI sequences retrieved in this study were conjointly analyzed with BOLD/GenBank sequences of the other Sphaerophoria species to evaluate whether COI possessed a sufficient diagnostic value as a DNA barcode marker to consistently delimit allospecific individuals. Additionally, the aforementioned characters were used to inspect the population structure of S. scripta in Europe using methods based on individual‐ and population‐based genetic differences, as well as geometric morphometrics of wing traits. The results indicate numerous shared COI haplotypes among different Sphaerophoria species, thus disqualifying this marker from being an adequate barcoding region in this genus. Conversely, the analyses of population structuring revealed high population connectivity across Europe, therefore indicating strong tolerance of S. scripta to environmental heterogeneity. The results imply a multilocus approach as the next step in molecular identification of different Sphaerophoria species, while confirming the status of S. scripta as a powerful biocontrol agent of economically relevant aphid pests.

Sexual size and shape dimorphism, and allometric scaling in the pupal and adult traits of Eristalis tenax

“…Female-biased SSD observed in our study is complementary to the findings of the studies of drone fly populations (Francuski et al, 2011; and several eristaline species (Gilbert, 1985), and Sphaerophoria scripta (Gojković et al, 2020). Hence, our results essentially confirmed the findings of the previous studies in insects (e.g.…”

“…Female‐biased SSD observed in our study is complementary to the findings of the studies of drone fly populations (Francuski et al, 2011; Francuski, Ludoški, & Milankov, 2013) and several eristaline species ( Eristalis arbustorum : Francuski et al, 2020; E. interrupta : Francuski, unpublished data), Merodon species ( M. albifrons : Milankov et al, 2013; M. avidus : Milankov et al, 2009; M. testaceus : Ludoški, unpublished data), Syrphus ribesii (Gilbert, 1985), and Sphaerophoria scripta (Gojković et al, 2020). Hence, our results essentially confirmed the findings of the previous studies in insects (e.g.…”

“…Consistent SD in wing shape is evident in other hoverfly taxa, suggesting that wing shape in hoverflies is sex‐specific. For instance, females possess broader and more rounded wings in Cheilosia (Ludoški, 2008; Ludoški et al, 2008; Milankov et al, 2010a, 2010b) and Merodon species (Milankov et al, 2013), while the displacement of inner landmarks caused variation in the relative position of veins in the central part of the wings in Eristalinus aeneus (Ludoški, unpublished data), Sphaerophoria scripta (Gojković et al, 2020), and Eristalis tenax (Francuski, 2012; Francuski et al, 2011; Francuski, Djurakic, Ståhls, & Milankov, 2014, results herein).…”

Novel Pipeline for Large-Scale Comparative Population Genetics

“…Low levels of genetic differentiation are not uncommon in Diptera. Populations have shown low genetic differentiation and high population connectivity in various regions at large geographic scales, including across Southeast Asia (Olival et al, 2013) and across several European countries (Gojkovic et al, 2020).…”

Detection rates of aphid DNA in the guts of larval hoverflies and potential links to the provision of floral resources

“…In general, minimal reference collection for target taxa represents a significant problem because a good estimate of intra- and interspecific variation of the genomic region in the target taxa is needed to assess the robustness of the ID system. In future work, longer amplified regions may increase our level of resolution and bespoke sequencing of additional species and individuals are required to augment existing reference collections to validate species level identifications and determine which species can (or cannot) be differentiated by this region (Gojković et al ., 2020).…”