Phylogenetic analysis of the tribe Dufouriini (Diptera: Tachinidae) using a total evidence approach based on adult and immature stages

Abstract

Dufouriini are a worldwide distributed tachinid tribe comprised of 51 species in 13 genera, made up of parasitoids of adult Coleoptera. The systematic positioning of Dufouriini has been controversial. Currently, it is placed within Dexiinae, but was previously placed in Phasiinae and Voriinae, and has even had the status of subfamily. Delimitation and composition of Dufouriini has also been debated, whether it is a single tribe or divided into two (Dufouriini and Freraeini) or three (Dufouriini, Oestrophasiini and Freraeini) tribes. Herein, we present the first phylogenetic analysis of Dufouriini based on total evidence using morphological data from adult and immature stages. The taxonomic sampling included all genera in Dufouriini (including Oestrophasiini) and also the genus belonging to Freraeini, a historically related tribe. Data matrix comprised 35 species and 22 genera in the ingroup, and 185 characters constructed from eggs, first instar larvae, puparia and adults, including female and male terminalia and spermathecae. The phylogenetic analysis recovered Dexiinae as paraphyletic in relation to Phasiinae, since the clade (Freraeini (Dufouriini + Oestrophasiini)) is more closely related to Phasiinae than Dexiinae. Dufouriini, Oestrophasiini and Freraeini are recovered as separate monophyletic tribes, strongly supported by a number of synapomorphies. Oestrophasiini is revalidated. A new synonymy is proposed: Comyopsis Townsend syn. nov. of Ebenia Macquart. Accordingly, Ebenia fumata (Townsend, 1919) is nomen preoccupatum by Ebenia fumata (Wulp, 1891), thus we change its specific epithet by designation of the new replacement name Ebenia neofumata Santis and Nihei [nomen novum]. The genera Mesnilana and Rhinophoroides are removed from Dufouriini and tentatively placed into Palpostomatini. Finally, Cenosomastat. rev., previously a subgenus of Oestrophasia, is revalidated as genus.

Dolichozelia gen. nov., a new genus of Dexiini (Diptera: Tachinidae) from Brazil

“…Thus, the characters that were traditionally used to delineate Dexiinae, derived from the external morphology that was used since Robineau-Desvoidy in 1830, it was deemed as insufficient to cover all the world diversity of Dexiinae, and, consequently Dexiini. As argued by Santis and Nihei (2022), further evidence was gathered from the works of the male terminalia by Verbeke (1962) and female terminalia by Herting (1957). Verbeke (1962) described the link between basiphallus and distiphallus as being 'indirect and mobile' and the 'posterior parameter' (pre-gonite) of type C (connective), was found in Dexiinae (Dexiini sensu O'Hara et al 2020), Voriinae (Voriini, in part) and Dufouriinae (Dufouriini, in part); he was the first to postulate a close relationship between them.…”

“…One of their results was that Dexiinae, with Voriini paraphyletic in relation to a monophyletic Dexiini, was recovered as paraphyletic in relation to Phasiinae. The traditional putative synapomorphy of Dexiinae (basiphallus with a membranous connection with the distiphallus) was not confirmed as synapomorphic by Cerretti et al (2014) and Santis and Nihei (2022), this character state was interpreted as having undergone a reversal, being secondarily lost in most Phasiinae.…”

“…All these synapomorphies were, as aforementioned, derived from the observations of Tschorsnig (1985). In addition, the presence of an granulate surface at the acrophallus was also recovered by Santis and Nihei (2022) as synapomorphic for Dexiini.…”

“…The traditional putative synapomorphy of Dexiinae (basiphallus with a membranous connection with the distiphallus) was not confirmed as synapomorphic by Cerretti et al . (2014) and Santis and Nihei (2022), this character state was interpreted as having undergone a reversal, being secondarily lost in most Phasiinae.…”

“…This information about the immature stages was mainly based on the studies from Thompson (1963) that described a ‘typical’ larval morphology of Dexiini that can be highlighted as follows: prominent conical antennae, a well‐developed recurved sensorial organ; spiracles forming a developed felt chambers, each opening at the end of an elongate tube; the body is covered almost all over with scale‐like plates, rounded behind and usually bearing a row of small acute teeth. This broad‐based, or holomorphological, approach is desirable in dexiines systematics, as well as tachinids overall (Santis & Nihei 2022), and this led Thompson (1963) to conclude that these traits from the first instar larva, in addition to the characters from the male (Verbeke 1962, and later, from Tschorsnig 1985) and female terminalia (Herting 1957) together with the traditional traits discussed by Mesnil (1966, 1980), would, putatively, confirm Dexiini as a natural group.…”