Heteromeringia CZERNY, 1903

Lonsdale, Owen & Marshall, Stephen A., 2007, Revision of the New World Heteromeringia (Diptera: Clusiidae: Clusiodinae), Beiträge Zur Entomologie = Contributions to Entomology 57 (1), pp. 37-80 : 39-40

Heteromeringia CZERNY ,, 1903

HeteromeringiaHeteromeringia CZERNY, 1903: 72. KERTESZ, 1903: 567. JOHNSON, 1913: 98. MALLOCH, 1918: 7. MELANDER & ARGO, 1924: 28. MCAC LPINE 1960, 83-85. SASAKAWA, 1966: 61-100. Type species: Heteromeringia nigrimana (LOEW, 1864) (by monotypy).

Diagnosis

Outer angular extension on pedicel blunt and obtuse. Scutellum flattened and wrinkled dorsally. Subcostal break indistinct. Three or four fronto-orbital bristles, reclinate except for inclinate anterior bristle. Interfrontal bristle absent. One small lateral scutellar bristle ( Fig. 8 ). Acrostichal bristle absent. Tibiae without dorsal preapical bristles. Distiphallus elongate, thin, with one pair of heavily-sclerotized lateral “ribs” and usually with accessory distal sclerites ( Fig. 12 ). Ejaculatory apodeme elongate with apex fan-shaped (shown from different angles in Figs 24, 36 and 53).

Generic description

General. Body length 2.4-5.0 mm. Colour predominantly brown to black, sometimes yellow with variable dark pattern. Face flat and microsetulose. Arista sparsely plumose to pubescent. Outer angular extension on pedicel blunt and obtuse; inner extension absent. Antenna arising at midpoint of head. Frons almost always with medial pilose patch on anterior half or more (often reduced in females). Postcranium concave. Scutellum flattened dorsally and longitudinally wrinkled. Subcostal break indistinct. Wing clear to variably patterned. M 1+2 ratio (length of the ultimate section of vein M 1 divided by length of penultimate section) 4.0-12.0 (usually 4.5-8.0). Fore tarsi usually with slight lateral compression (pronounced in some Old World species).

Chaetotaxy

Bristles black to brown. Three or four fronto-orbital bristles, reclinate except for inclinate anterior pair; anterior two bristles closely spaced near anterior margin of frons and hind pair positioned near posterior margin; fourth bristle sometimes present between anterior two pairs but less than 2/3 length of other bristles. Postvertical and ocellar bristles divergent, minute to large. Interfrontal bristle absent. Vibrissa well-developed. Usually five to seven short genal bristles (anterior bristle sometimes vibrissa-like). Two subgenal bristles. Pedicel with one outstanding dorsal bristle. Occiput with row of short bristles behind eye margin. Two postsutural dorsocentral bristles, with anterior bristle usually 3/5-4/5 times length of posterior bristle; sometimes small additional bristle directly in front of anterior dorsocentral. Scutellum with one small lateral bristle and one long incurved apical bristle ( Fig. 8 ). Acrostichal bristle absent. One postpronotal, two notopleural, two postsutural intra-alar and sometimes one small to minute intra post-alar bristle. 1-2 ( Fig. 8 ) strong anepisternal and 1 katepisternal bristle. Tibiae without dorsal preapical bristles. Male fore and mid femora with ventral row of ctenidial bristles.

Male abdomen and terminalia

Tergite 1 narrow and fused to tergite 2; tergites 3-6 and sternites 2-5 well-developed, separate; sternite 1 reduced to thin strip; sternites 2-5 well-developed. Sternites 6- 8 forming complete asymmetrical ring (= “annulus”); sternite 8 setose and dorsal with right lateral extension; sternite 7 on left side between sternites 6 and 8, heavily sclerotized anteriorly; sternite 6 fused to sternite 7 laterally, heavily sclerotized anteriorly, and weakly attached to sternite 8 ventrally; sternites 6 and 7 variably differentiated ventrally into weakly sclerotized, folded and/or widened regions, forming enlarged membranous “pocket” to enclose distiphallus when it is at rest. Spiracles in membrane ventral to tergites 1-5, (often) dorsolaterally between sternites 6 and 7, and ventrally between sternites 6 and 8. Epandrium dome-shaped, evenly bristled ( Figs 10 and 11 ), and usually much narrower than abdomen. Surstylus variable in shape ( Figs 10 , 17 , 33 and 51 ), but often less than 2/3 length of epandrium and rounded (very thin if longer); small rounded bristles apical on inner face. Cerci variable ( Figs 11 , 14 , 18 , 32 and 47 ), but usually less than half length of epandrium and often united. Hypandrium fused to pregonite (shape globose to triangular in profile) ( Fig. 12 ), sparsely setose (bristles usually short and stout) and sometimes with distal setulae; hypandrial arm short and stout. Postgonite, epiphallus and lateral lobe of distiphallus absent. Phallapodeme 0.5-1.0 times length of hypandrium + pregonite. Basiphallus fused to distiphallus anteriorly. Distiphallus very elongate, dark, thin, with one pair of heavily-sclerotized lateral “ribs”, and often with distal accessory sclerites. Ejaculatory apodeme elongate with apex fan-shaped.

Female abdomen and terminalia

Tergites 1 and 2 fused; tergites 3-6 and sternites 2-6 complete; sternite 1 reduced to thin anterior strip. Segments 7 and 8 narrowed into long, thin tube; terminal segments separated by long membranous area. Spiracles in membrane below tergites on segments 1 to 7. Cerci as long as sternite 10, length four times width. Spermatheca (one pair) pigmented ( Figs 28-30 and 48-50 ); shape variable, but usually small, transversely wrinkled, cylindrical and telescoped. Genital chamber membranous and elongate. Spermathecal duct weakly sclerotized. Ventral receptacle sac-like (widest subapically), recurved, and with long, sometimes loosely coiled, subterminal flagellum ( Fig. 29 ).

Figures

Fig. 8: Heteromeringia czernyi KERTESZ, left lateral with detail of anepisternum and arrow indicating diagnostic upturned bristle. Fig. 9: H. fumipennisfumipennis MELANDER & ARGO, anepisternum with arrow indicating diagnostic lateral disc.

Figs 10-12: Heteromeringia fucatafucata HENDEL, genitalia. 10 external, left lateral; 11 external, posterior; 12 internal, left lateral. Ejaculatory apodeme omitted.

Figs 16-18: Heteromeringia nanellananella sp. n., genitalia. 16 internal, left lateral; 17 external, left lateral; 18 external, posterior. Ejaculatory apodeme omitted.

Figs 31-33: Heteromeringia czernyi KERTESZ, external terminalia. 31 left lateral; 32 posterior; 33 right surstylus, left lateral.

Figs 51-53: Heteromeringia apholis sp. n., genitalia. 51 external, left lateral; 52 external, posterior; 53 internal, left lateral.

Figs 13-15: Heteromeringia fumipennis MELANDER Figs 19-21: Heteromeringia nigripes MELANDERELANDER & & ARGO, genitalia. 13 external, left lateral; 14 exter- ARGO, genitalia. 19 external, left lateral; 20 external, posterior; 15 internal, left lateral. Ejaculatory nal, posterior; 21 internal, left lateral. Ejaculatory apodeme omitted. apodeme omitted.

Figs 45-47: Heteromeringia quadriseta sp. n., genitalia. 45 internal, left lateral; 46 external, left lateral; 47 external, posterior. Ejaculatory apodeme omitted.

Figs 28-30: Female internal genitalia (spermathecae and ventral receptacle). 28 Heteromeringia fumipennis MELANDER & ARGO; 29 H. nitida JOHNSON; 30 H. nigripesnigripes MELANDERELANDER & ARGO.

Figs 48-50: Female internal genitalia (spermathecae and ventral receptacle). 48 Heteromeringia czernyi KERTESZ; 49 H. flavifronsflavifrons HENNIG; 50 H. lateralis sp. n.