The flower flies and the unknown diversity of Drosophilidae (Diptera): a biodiversity inventory in the Brazilian fauna

Abstract

Diptera is a megadiverse order, reaching its peak of diversity in Neotropics, although our knowledge of dipteran fauna from this region is grossly lacking. This applies even to the most studied families, such as Drosophilidae. Despite its prominence, most aspects of the biology of these insects are still poorly understood, especially those linked to natural communities. Field studies on drosophilids are highly biased towards fruit-breeding species. Flower-breeding drosophilids, however, are worldwide distributed, especially in tropical regions, although being mostly neglected. The present paper shows the results of a biodiversity inventory of flower-breeding drosophilids carried out in several localities in Brazil, based on samples of 125 plant species, from 47 families. Drosophilids were found in flowers of 56 plant species, from 18 families. The fauna discovered turned out to be mostly unknown, comprising 28 species, with 12 of them (> 40%) still undescribed. Not taking into account opportunistic species, two-thirds of the flower-exclusive diversity was undescribed. The Drosophila bromeliae species group was the most representative taxon, with eight species (six undescribed), including four polyphagous and four Solanum-specialized species. This specialization on Solanum is reported for the first time for Drosophilidae. Other taxa of restricted flower-breeding drosophilids were the Drosophila lutzii species group and two species of the genus Zygothrica Wiedemann. Some specimens of the genera Cladochaeta Coquillett, Rhinoleucophenga Hendel and Scaptomyza Hardy were found, but their relations to flowers are unclear. Additionally, ten species of broad niche were found using flowers opportunistically. Localities and host plants were recorded for all species collected.

First report of colored pan traps to capture Drosophilidae (Diptera)

“…Drosophila proved to be the most representative genus of fauna associated with colored pan traps, with the dominance of the species of the Phloridosa subgenus and bromeliae group in all the sampled months. Among them are D. lutzii, D. bromelioides, D. bromeliae, and D. denieri, which have a wide distribution in the Neotropical region and are found in a wide variety of plants (Frota-Pessoa, 1952;Petersen, 1960;Silva and Martins, 2004;Blauth and Gottschalk, 2007;De Toni et al, 2007;Gottschalk et al, 2007;Grimaldi, 2016;Schmitz and Valente, 2019;Cordeiro et al, 2020). In recent studies, Cordeiro et al (2020) and Schmitz and Valente (2019) investigated the Drosophilidae fauna associated with flowers in Brazil and demonstrated that these species are the most representative, corroborating the efficiency of pan traps for capturing anthophilous Drosophilidae.…”

“…Concerning the knowledge of Scaptomyza, the second most abundant genus present in this study, the literature mentions that its species are mainly saprophagous (Hackman, 1959;Brncic, 1983;Markow and O'Grady, 2008). In addition to this habit, some species of Scaptomyza are randomly sampled using other breeding sites, such as spider egg bags, mustard leaf-miners (Brassicaceae), and some are predators (Montague and Kaneshiro, 1982;Magnacca et al, 2008;Markow and O'Grady, 2008;Lapoint et al, 2013;Schmitz and Valente, 2019).…”

“…The individuals removed from the traps were fixed in absolute alcohol and identified based on external morphology, using taxonomic keys and species descriptions according to specialized literature (Burla, 1956;Grimaldi, 1987;Vilela and Bächli, 1990;Grimaldi, 2016;Schmitz and Valente, 2019). Individuals of cryptic species were prepared and dissected for later identification of terminalia (females species were identified to external morphology and associated with males, respectively) (Bächli et al, 2004).…”

“…Drosophilidae (Insecta, Diptera) is considered the ideal model for studying different ecological issues, such as edge effect and human disturbance, for example (Mata et al, 2008(Mata et al, , 2010Penariol and Madi-Ravazzi, 2013). One of the main reasons behind this practice is its ability to use a wide variety of resources as substrate (mainly fruits, flowers and macroscopic fungi) (Carson, 1971;Grimaldi, 1987;Markow and O'Grady, 2008;Valer et al, 2016;Mendes et al, 2017;Schmitz and Valente, 2019). Some different methods are common to insect surveys, such as the banana attractive trap (Gottschalk et al, 2007;Bizzo et al, 2010;Hochmüller et al, 2010;Emerich et al, 2012;Garcia et al, 2012;Poppe et al, 2012;Duarte et al, 2018;Mateus et al, 2018), use of entomological nets, collection in flowers (Schmitz and Valente, 2019;Cordeiro et al, 2020), collection in macroscopic fungus resources (Gottschalk et al, 2009;Valer et al, 2016) and pan traps (Westphal et al, 2008;Halinski et al, 2018).…”

“…One of the main reasons behind this practice is its ability to use a wide variety of resources as substrate (mainly fruits, flowers and macroscopic fungi) (Carson, 1971;Grimaldi, 1987;Markow and O'Grady, 2008;Valer et al, 2016;Mendes et al, 2017;Schmitz and Valente, 2019). Some different methods are common to insect surveys, such as the banana attractive trap (Gottschalk et al, 2007;Bizzo et al, 2010;Hochmüller et al, 2010;Emerich et al, 2012;Garcia et al, 2012;Poppe et al, 2012;Duarte et al, 2018;Mateus et al, 2018), use of entomological nets, collection in flowers (Schmitz and Valente, 2019;Cordeiro et al, 2020), collection in macroscopic fungus resources (Gottschalk et al, 2009;Valer et al, 2016) and pan traps (Westphal et al, 2008;Halinski et al, 2018). However, although historically the use of different methodologies for capturing individuals with different ecological and evolutionary behaviors seems to be clear to measure the fauna of the natural environments, analyzing articles that present local researches of Drosophilidae reveals that the way the individuals are captured is little variable from one study to another.…”