Paragini, with the single genus Paragus, is a compact and distinctive group occurring in all continents other than South America and Antarctica. Paragus species are small, slender to moderately robust, with thorax black or with apex of scutellum pale, and abdomen usually extensively red-orange to entirely black. Paragus has postpronotum bare, antenna short, anterior anepisternum bare, abdomen parallel-side, face yellow in background colour, metaepisternum bare, scutum black laterally, at most with a poorly defined yellow polinose vitta, and metasternum bare.
The subgenus Serratoparagus sensu Vujic et al. (2008) has eyes with vittae of pile; face with distinct facial tubercle; scutum usually with long, submedian pollinose vittae reaching the posterior margin; scutellum with conspicuous teeth on posterior margin; spurious vein ending before meeting point of vein M1 with DM; abdomen short and elliptical; tergum 1 large, longer than distance between its posterior margin and the posterior margin of tergum 2; terga 1–5 completely fused, at least laterally; the posterior margins of terga 3 (female) and 4 (in both sexes) visible except laterally; male genitalia: minis large, lateral arms of minis short; epandrium in narrower part slightly shorter than or of same length as cercus; ejaculatory apodeme large, umbrella-like; lateral lobe of aedeagus strongly fused with aedeagal apodeme; aedeagus in ventral view ‘amphora-like’, very broad, petiolate basally; postgonite plate-like, pilose.
New description:
FEMALE.
Head: Face with small facial tubercle, yellow with medial black vitta, black ventrolaterally on gena and epistoma, white pilose, densely white pollinose between yellow and ventral black areas; gena small, black; frons black, white pilose, white pollinose laterally on eye margins not reaching ocellar triangle and broadening dorsally; vertical triangle black, black pilose; eye pilose, with three more less well-defined white pilose vittae; antenna brown, basoflagellomere elongate, orange ventrally; arista subbasal; occiput black, silver pollinose, withe pilose.
Thorax: Scutum black with two dorsomedial white pollinose vittae, golden pilose; postpronotum bare; scutellum with conspicuous teeth on posterior margin, black basally, yellow apically, golden pilose, subscutellar fringe complete with yellow pile. Pleuron black, white pollinose on posterior anepisternum and katepisternum, with long white pile; metasternum bare; calypter yellow; plumula yellow; halter yellow; spiracular fringes yellow. Wing: Wing membrane hyaline, broadly bare basally, with scarce microtrichia apically. Legs:procoxa and protrochanter black, profemur black on basal half, yellow apically, protibia yellow basally, brown on apical half, protarsus brown; meso leg similar to proleg; metaleg similar to proleg except metafemur black on basal 4/5 and metabasotarsomere slightly broadened.
Abdomen: Parallel-sided, convex, punctuate, white pilose. 1st tergum black; 2nd tergum orange, black laterally; terga 3 and 4 orange on anterior margin, black on posterior half with medial black vitta and two submedial arcuate white pollinose fasciate maculae; tergum 5 similar to 3 and 4, but white pollinose macula on orange area, black anteriorly.
Paragus (Serratoparagus) crenulatus Thomson, 1869.
Thomson, C.G. (1869) Diptera. Species nova descripsit. Pp. 443-614, In Kongliga svenska fregatten Eugenies resa omkring jorden under befal af C. A. Virgin, åren 1851-1853. 2 (Zoologi) 1, Insecta. P. A. Norstedt & Soner, Stockholm. 617 pp., pl. 9. [after 1869.02.10, before1869.03.10]
GenBank accession number for this species are: protein-coding COI gene (AY476862; AY476863), and rRNA 28S gene (AY476880; AY476879).
Paragus is the only genus of the tribe Paragini and its phylogenetic position is uncertain. Dusek and Laska (1967) did not comment on the sister group of Paragus but mentioned that the genera Didea and Paragus share some characters of the adult morphology and male genitalia and they placed Paragini as one of the first branches of Syrphinae, commonly called basal clades. Shatalkin (1975) said that Paragini was a tribe aberrant in relation to all other tribes of the subfamily based on characters of the male genitalia. Rotheray and Gilbert (1989) using larval characters, resolved the genus as sister group of the tribe Pipizini. In 1999, Rotheray and Gilbert reported Paragus as sister group of the clade Eupeodes + Scaeva + Ischiodon.
Ståhls et al. (2003) using morphological and molecular characters resolved Paragus as sister group of the genera Chrysotoxum and Syrphus. Hippa and Ståhls (2005), based only on adult morphological cahracters, found a similar conclusion: Paragus as sister group of Chrysotoxum, Syrphus, Toxomerus and Sphaerophoria. Mengual et al. (2008) using only molecules, resolved Paragini as sister group of Allobaccha, a position never suggested before.
Although there are recent studies about the intrageneric classification of Paragus (Kassebeer, 1999a,b, 2001; Rojo et al., 2006; Vujic et al., 2008), the placement of this tribe in the subfamily Syrphinae is unresolved as previous results disagree. Currently there are four subgenera based on the study by Vujic et al. (2008): Paragus s. str., Serratoparagus, Afroparagus and Pandasyopthalmus (the latest with two species groups, tibialis and jozanus groups).
Larvae of P. crenulatus have been reported feeding on Aphis craccivora, Aphis gossypii, Aphis spiraecola, Lipaphis erysimi, Pentalonia nigronervosa, and Toxoptera aurantii (Aphididae) (Rojo et al. 2003).
Species known from the entire Oriental Region, China and Australia (NT, QLD).
unless otherwise stated