Murphy, W.L., Mathis, W.N., and Knutson, L.V. 2018. Comprehensive taxonomic, faunistic, biological, and geographic inventory and analysis of the Sciomyzidae (Diptera: Acalyptratae) of the Delmarva region and nearby states in eastern North America. Zootaxa 4430(1): 001–299. (Ligação)
The Nearctic species of Euthycera require revision. Euthycera mira Knutson and Zuska is a valid, distinctive species from the Nearctic portion of Mexico (Knutson & Zuska 1968) and Montana (see Literature Cited, Murphy spreadsheet of determinations). What has been considered to be a single species, E. flavescens or E. arcuata (Loew) or E. borealis Cresson (synonymy remains to be determined), might comprise as many as three species north of Mexico that are especially widespread in eastern North America, based on preliminary studies by LVK and R.E. Orth (1976–1977, unpubl.) and LVK, R.E. Orth, and J-C. Vala (1999–2000). R.E. Orth's final, inked illustrations and photocopies of the other figures are deposited at the USNM.
Type specimens of nominate Nearctic species currently (2017) are in the USNM on loan from the MCZ and ANSP. Included from the MCZ are the male lectotype of E. arcuata from "Washington" (terminalia not examined) and two male paratypes from "Chicago, Ill." (terminalia preliminarily examined) and the male holotype of E. flavescens from "Carolina" (terminalia preliminarily examined). Included from the ANSP are the male holotype of E. borealis from "Black Mt., N.C., Nr. Fork Swannanoa" and one male paratype (in good condition, terminalia preliminarily examined).
Vala (1983) studied one male from Vermont, one male from "Glenside" [Pennsylvania?], and one male from "Louisiana" that he identified as E. arcuata. He did not indicate from which specimen(s) his descriptions and illustrations were prepared. Because the taxonomy of Nearctic species of Euthycera is unresolved and more than one species might occur in the Vermont-to-Louisiana area, Vala's descriptions and figures are in question as they potentially represent a mixture of species. We use E. flavescens as the oldest of the three names of these species.
They treat this as a single Nearctic species (which is in line with what it says on bugguide and in Marshall's Flies), pending revision, but they resurrect E. flavescens as the valid name, of which the more commonly used E. arcuata would be a junior synonym. This change was subsequently followed by Schorno et al. 2019 in Sciomyzidae of northeastern North America.
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.
Change proposed by Murphy et al. 2018 in Comprehensive taxonomic, faunistic, biological, and geographic inventory and analysis of the Sciomyzidae (Diptera: Acalyptratae) of the Delmarva region and nearby states in eastern North America.
The relevant section reads:
They treat this as a single Nearctic species (which is in line with what it says on bugguide and in Marshall's Flies), pending revision, but they resurrect E. flavescens as the valid name, of which the more commonly used E. arcuata would be a junior synonym. This change was subsequently followed by Schorno et al. 2019 in Sciomyzidae of northeastern North America.