Microphorella arcana, Brooks & Cumming, 2025

Brooks, Scott E. & Cumming, Jeffrey M., 2025, Revision of the Microphorella acroptera species group and establishment of the Microphorella arcana species group (Diptera: Dolichopodidae sensu lato: Parathalassiinae), Zootaxa 5661 (4), pp. 451-503 : 493-494

Microphorella arcana species group

Diagnosis. The Microphorella arcana species group can be distinguished from other Nearctic Microphorella species groups by the following suite of characters: clypeus separated from face by suture; mouthparts with sensory pit on palpus (sometimes difficult to see in non-macerated specimens); male hind trochanter setulose, lacking tubercle; male hind femur with dense patch of fine setae on posterior surface ( Figs 107, 109 ); wing with moderately long R 1 vein that terminates beyond midpoint of wing ( Fig. 106 ); male abdominal sternite 5 with subtriangular apically tapered ventral projection; hypopygium ( Figs 110–113 ) with epandrium and hypandrium mostly separate, with margins defined; right epandrial lamella with dorsally directed ventral process; hypandrium bare; female abdomen (only known for M. gilaensis sp. nov.) with tergite 5 bearing a cluster of stout median setae, tergite 6 with setae on posterior margin unmodified (i.e., not forming prominent row of long, stout setae), syntergite 9+10 with acanthophorous spines and cercus narrow and pointed.

Distribution. The M. arcana species group is known from California and central Arizona.

Remarks. The dense patch of fine setae on the posterior surface of the male hind femur ( Figs 107, 109 ) and the dorsally directed ventral process of the right epandrial lamella ( Figs 111 , 113 ) are considered to be synapomorphies supporting the monophyly of the M. arcana species group.

Included species. This group includes the following species: M. arcana sp. nov., M. gilaensis sp. nov. and M. ovata sp. nov. A fourth species, Microphorella sp. B , is recognized but not formally named and described because the terminalia of the unique male specimen is missing.

Figures

FIGURES 106–109. Male habitus, legs and abdomen of Microphorella arcana sp. nov. and M. ovata sp. nov. 106. Habitus of M. arcana sp. nov. holotype. 107. Body and legs of M. arcana sp. nov. holotype, dorsolateral view, arrows indicate setae on hind femur and bulbous projection on sternite 6. 108. Legs and abdomen of M. arcana sp. nov. holotype, left lateral view, arrow indicates setae on sternite 5. 109. Body and legs of M. ovata sp. nov. paratype, posterolateral view, arrow indicates setae on hind femur.

FIGURES 110–111. Hypopygium of Microphorella gilaensis sp. nov. holotype. 110. Left lateral view. 111. Right lateral view. Abbreviations: cerc—cercus; d sur—dorsal lobe of surstylus; hypd—hypandrium; hyprct—hypoproct; pgt lb—postgonite lobe; ph—phallus; v epand proc—ventral epandrial process; v sur—ventral lobe of surstylus.

FIGURES 112–114. Hypopygium of Microphorella ovata sp. nov. paratype (CNC1155848). 112. Left lateral view. 113. Right lateral view. 114. Left ventral lobe of surstylus, posterior view. Abbreviations: cerc—cercus; d sur—dorsal lobe of surstylus; hypd—hypandrium; pgt lb—postgonite lobe; ph—phallus; v epand proc—ventral epandrial process; v sur—ventral lobe of surstylus.