Cleigastra Macquart, 1835

Ozerov, A. L. & Krivosheina, M. G., 2015, A review of the genera Cleigastra Macquart, Gonarcticus Becker, Gonatherus Rondani, Hexamitocera Becker, Nanna Strobl, Orthacheta Becker and Spathephilus Becker (Diptera, Scathophagidae) of Russia, Zootaxa 4012 (2), pp. 201-258 : 204-206

Cleigastra Macquart, 1835

Cleigastra Macquart, 1835: 384 . Gender: feminine. Type species: Cordylura apicalis Meigen, 1826 , by designation of Westwood (1840: 144).

Cnemopogon Rondani, 1856: 100 . Gender: masculine. Type species: Cordylura apicalis Meigen, 1826 , by original designation.

Clidogastra : error ( Becker, 1894: 179).

Two species are known in the world, both occurring in Russia ( Gorodkov 1986; Ozerov & Krivosheina 2014b).

Cleigastra species are slender, medium-sized flies (4.3–7.2 mm long). Head. Frons black. Face, parafacial and gena pale yellow. Postcranium black, greyish dusted, covered with yellow hairs and with black postocular setulae. Chaetotaxy: 3 orbital, 2–3 frontal, 1 ocellar, 1 inner vertical, 1 outer vertical (short), 1 postocellar; 1 pair of strong vibrissae and 2 pairs of short subvibrissae present. Antenna black. Postpedicel with acutely angled upper apical corner, long, approximately 4–4.5 times as long as wide. Arista black, pubescent throughout its length. Palpus long, yellow.

Thorax black, greyish dusted. Scutum with following setae: acrostichals in two rows, prescutellar pair not differentiated or only slightly longer than the other hairs on scutum, dorsocentrals 3+3, intra-alars 0+2, supra-alars 1+2, postpronotals 2, notopleurals 2, postalars 2. Proepisternum usually bare in central part (rarely with several hairs), with 2 setae near lower margin. Proepimeron with 1 seta. Anepisternum covered with hairs in posterior half (pale yellow in male and black in female) and with 2–4 black setae along posterior margin. Katepisternum covered with long setae in ventral corner (the setae pale yellow in male and black in female) and 3 strong setae. Anepimeron bare. Scutellum black, with pair of strong lateral scutellar setae and pair of apical setulae.

Legs. Coxae and fore femora yellow to black, tibiae yellow, tarsi black. Male coxae inside and femora ventrally with long hairs and setae. Fore femur with rows of dorsal, posterodorsal and anterior setae. Fore tibia with 2 posterodorsal, 2 anterodorsal and 1 posterior setae at middle, and apical ventral, dorsal and posterior setae. Mid femur with 1 anteroventral seta on apical half and row of anterior setae, also with preapical posterior and posterodorsal setae; in female additionally with 3–4 long ventral setae on basal half. Mid tibia with 2 anterodorsal, 2 posterodorsal, 1 posterior (posteroventral), 1 anteroventral setae and ring of apicals; posterior (posteroventral) surface with 1–3 thin setae in male and with 1 stong seta in female. Hind femur with row of anterodorsal setae, also with 1 preapical posterodorsal and 2–3 dorsal setae; in female additionaly with rows of posteroventral and anteroventral setae. Hind tibia with 2–3 anterodorsal, 2–3 posterodorsal, 1–2 anteroventral, 0–1 posterior (posteroventral), 1 dorsal setae and ring of apicals.

Wing tinged with brownish; veins blackish; vein R1 setulose on apical third of dorsal surface. Calypters, margins of calypters, and halteres yellowish.

Abdomen cylindrical, black, greyish dusted, covered with black hairs. Tergites 2–6 each with row of long marginal setae. Sternite 4 simple, 2 times as long as wide. Sternite 5 with triangular-shaped lobes ( Figs 17 , 22 ). Surstyli simple, cerci fused ( Figs 18, 19 , 23, 24 ). Ovipositor long, cylindrical ( Figs 14–16 ). Female tergite 7 desclerotized in middle, its lateral margins fused with lateral margins of sternite 7 forming syntergosternite ( Fig. 16 ), as in several Nanna ( Fig. 103 ). Tergite 8 of V-like form, sternite 8 as two small round sclerites.

Adults are found in wet localities like the edges of lakes, rives or ponds. According to Groth (1969) larvae of C. apicalis inhabit tunnels of larvae of Noctuidae (Lepidoptera) , where they feed mainly on the frass of the caterpillars or on dead caterpillars. Grochowska (2006) described the second- and third-instar larvae and pupa of C. apicalis . Observations by Grochowska showed that second- and third-instar larvae “were found on reed stems inside the galls of Lipara lucens , L. similis , L. pullitarsis , L. rufitarsis , Platycephala planifrons and P. umbraculata and inside internodes attacked by Arenostola phragmitidis . On a few occasions larvae were also found among decaying plant tissue in the apical part of stems not inhabited by other insect species”. Larvae inside galls feed primarily on dead plant tissue.

Figures

FIGURES 14 – 21. Cleigastra apicalis (Meigen): 14 — end of female abdomen, ventral view; 15 — same, dorsal view; 16 — same, lateral view; 17 — male sternite 5; 18 — epandrium, cerci and surstyli, lateral view; 19 — same, dorsal view; 20 — male sternite 4; 21 — distribution map.

FIGURES 22 – 29. Cleigastra sundukovi Ozerov (22 – 24, 29) and Gonarcticus abdominalis (Zetterstedt) (25 – 28): 22 — male sternites 4 (lower) and 5 (upper); 23, 26 — epandrium, cerci and surstyli, lateral view; 24, 27 — same, dorsal view; 25 — male sternites 5; 28 — male sternites 4; 29 — distribution map. Figures 22 – 24 after Ozerov (2013, Figures 21 – 23).

FIGURES 103 – 110. Nanna flavipes (Fallén): 103 – 105 — female abdominal sternite 8; 106 — male sternite 5; 107 — epandrium, cerci and surstyli, lateral view; 108 — same, dorsal view; 109 — male sternite 4; 110 — distribution map.