Paramixogaster contracta
Creators: name: Reemer, Menno
name: Sankararaman, Hariharakrishnan
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Paramixogaster
Paramixogaster contracta

description: Paramixogaster contracta (Brunetti)
Figs 15, 17, 32–38, 119–122, 114–116, 130
Microdon contractus Brunetti, 1923: 310. Holotype ♀: India (NHMUK) [examined]; Knutson et al. 1975: 370.
Paramixogaster contractus (Brunetti) – Reemer and Ståhls 2013 a: 145.
Microdon subpetiolatus Thompson, 2020: 87. Syn. nov., comb. nov. Holotype ♂: Sri Lanka, Ratnapura District, Singharaja Forest (USNM) [examined].
Studied type specimens.
Holotype of Microdon contractus Brunetti, 1923. India • 1 ♀; Deesa; 1922; C. G. Nursee leg.; NHMUK. Label 1 (round, red-bordered): “ Holotype ”; label 2: “ Deesa // P. T. O // 3. 97. ”; label 3: “ India: // Pres. by // Col. C. G. Nurse. // 1922 309. ”; label 4: “ Microdon // contractus // Brun Type [female] // det. Brun. 1921 ”.
Holotype of Microdon subpetiolatus Thompson, 2020. Sri Lanka • 1 ♂; coll. USNM. Label 1: “ SRI LANKA: Rat. Dist. // Singharaja forest // 5 VIII 1973 600 ft. // Ginter Ekis ”; label 2: “ collected // in Malaise // trap ”; label 3 (large, orange): “ Holotype // Microdon // subpetiolatus // Thompson ‘ 19 ”; label 4 (with QR-code): “ USNMENT // 01541885 ”.
Paratype of Microdon subpetiolatus Thompson, 2020. Sri Lanka • 1 ♂; coll. USNM. Label 1: “ SRI LANKA: Tri. Dist. // Trincomalee, China // Bay Ridge Bungalow // 0–100 ’, 13–17 - V- 1976 ”; label 2: “ Collected by // K. V. Krombein // P. B. Karunaratne // S. Karunaratne // D. W. Balasooriya ”; label 3: “ Microdon // 08-03 // det. // FC Thompson 19 ”; label 4 (yellow): “ Paratype // Microdon // subpetiolatus // FCT- 2010 ”; label 5 (with QR-code): “ USNMENT // 01541884 ”.
Diagnosis.
Body length: male 7.5 mm, female 9 mm. This species and P. conveniens share a unique character among Microdontinae: a setulose metanepisternum. Within Paramixogaster, both species also stand out because of the complete transverse suture on the mesoscutum. Paramixogaster contracta differs from P. conveniens in the following characters: legs entirely yellow (femora partly black in P. conveniens) and vein M 1 recurrent at more or less right angle (acute angle in P. conveniens). Male genitalia as in Fig. 130.
Redescription
(based on holotype of M. contractus Brunetti). Adult female. Body length: 9 mm.
Head. Face occupies 45 % of head width in frontal view, with sides below antennae parallel; black; entirely white setulose. Gena widely developed; black; white setulose. Oral margin not notched anteriorly, laterally not produced. Frons and vertex blackish brown; white setulose. Ocellar triangle not elevated. Occiput black; white setulose. Eye very sparse and short setulose, almost bare. Antennal fossa approximately as high as wide. Antenna dark brown, scape paler; postpedicel ~ 1.25 × as long as scape. Postpedicel parallel-sided with rounded apex; with small sensory pit at apical 1 / 3. Arista slender, ~ 1 / 2 as long as postpedicel.
Thorax. Mesoscutum shining blackish brown; entirely white setulose. Postpronotum pale brown; bare. Postalar callus pale brown; white setulose. Scutellum shining blackish brown; white setulose. Anepisternum with shallow sulcus separating posterior from anterior part; blackish; white setulose, with small bare part ventro-medially. Anepimeron blackish; entirely white setulose. Katepisternum blackish brown; white setulose dorsally; bare ventrally. Katatergite pale brown; long microtrichose. Anatergite pale brown; short microtrichose. Calypter and halter yellow.
Wing: hyaline; microtrichose, except bare on cells bc and c, basal 3 / 5 of cell r 1, basal 1 / 4 of cell r 2 + 3, basal 1 / 3 of cell r 4 + 5, antero-basal 1 / 6 of cell dm, entirely on cells br and bm, basal 2 / 3 of cell cup, and medially on alula.
Legs: Pale yellow; yellow to white setulose.
Abdomen. Tergite 2 constricted and tergites 3 and 4 widened; narrowest point at anterior 1 / 4 of tergite 2, widest at posterior margin of tergite 3. Tergites blackish brown, except anterior 1 / 2 of tergite 2 pale yellow; white setulose, except with short brown setulae on posterior 1 / 2 of tergite 2 and posterior 2 / 3 of tergite 3, with white setulae long and conspicuous on anterior 1 / 3 of tergite 3 and anterior 1 / 2 of tergites 4 and 5. Tergite 2 with median tubercle on anterior 1 / 3. Sternites pale brown; yellow setulose.
Male (based on holotype and paratype of M. subpetiolatus Thompson).
As female, except for following differences. Body length: 7.5 mm. Face occupies 42–46 % (n = 2) of head width in frontal view. Postpedicel 1.2–1.4 × as long as scape (n = 2).
Notes.
The type specimen of Microdon contractus Brunetti (a female) (Figs 32–38) was compared to those of M. subpetiolatus Thompson (male holotype and male paratype: Figs 109 – 116). They were found to be very similar, except for some differences usually associated with sexual dimorphism, such as a slightly wider abdomen in the female. No differences were found that could support specific taxonomic status for both taxa, so they are here considered as synonyms, with M. subpetiolatus Thompson syn. nov. as the junior synonym.
Distribution.
Known from India (Gujarat: Deesa) and Sri Lanka.
description: Published as part of Reemer, Menno & Sankararaman, Hariharakrishnan, 2024, Revision of the Oriental species of the hoverfly genus Paramixogaster Brunetti, 1923 (Diptera, Syrphidae, Microdontinae), pp. 1-48 in ZooKeys 1208 on pages 1-48, DOI: 10.3897/zookeys.1208.122829