Pentachaeta inserta, McAlpine, 2014

McAlpine, David K., 2014, Review of the Australian Genus Pentachaeta (Diptera: Heleomyzidae), with Descriptions of Nine New Species, Records of the Australian Museum 66 (5), pp. 247-264 : 254-256

Pentachaeta inserta n. sp.

Figs 18–22

Type material. Holotype ♂. New South Wales: Mount Wilson, Blue Mountains , c. 33°31'S 150°23'E, c. 900 m, 5.xi.1977, D.K.M. ( AM K310593 ). Glued to card point, postabdomen in genitalia tube on same pin . Paratypes. New South Wales: 10♂♂, Mount Wilson, Jan., Mar. , Oct. , Nov., Dec., 1956–2002, D.K.M. ( AM, USNM) ; 1♂, Putty Road at Tinda Creek , Oct. 1987, D.K.M. ( AM) ; 1♂, Victoria Falls, Blue Mountains , Nov. 1965, D.K.M. ( AM) ; 1♂, Wentworth Falls , Nov. 1958, D.K.M. ( AM) ; 3♂♂, Jenolan Caves , no date, J.C.W. ( AM) .

Other material examined. New South Wales: Hungry Head, near Urunga ( AM); Mongalowe River, Monga Road ( ANIC); Clyde Mountain, 2400 ft [c. 730 m] ( AM); Clyde Mountain, Cabbage Tree Creek ( ANIC); Rutherford Creek, Brown Mountain ( ANIC); Tantawangalo Forest, near Candelo ( AM); Saw Pit Creek, Snowy Mountains ( AM); Maxwell’s Creek, Nadgee State Forest ( AM). Victoria: Bucklands, East Gippsland ( ANIC); Dynamite Creek, Bonang Highway ( ANIC); Martin’s Creek, Bonang Highway ( AM); Tunnel Bend, near Jamieson ( AM); Myer’s Creek, near Healesville ( ANIC); Fernshaw, near Healesville ( AM); Warburton ( AM); Belgrave, near Melbourne ( AM, MV, USNM); Sherbrooke Forest, near Ferntree Gully ( AM, ANIC); Splitters Falls, Wannon River, and Mount William, Grampians National Park ( AM). Tasmania: 2 miles [c. 3 km] east of Tonganah, Scottsdale district ( AM); Pieman River, near Rosebery ( AM); Renison Bell, Pieman River district ( AM); “Nat. Park” [Mount Field National Park] ( ANIC).

Description (male) Resembling P. edwardsi and related species without sexual dimorphism of tibiae; agreeing with description of that species, except as indicated below.

Coloration generally as for genus; details as given for P. edwardsi .

Abdomen. Surstylus ( Fig. 18 ) moderately elongate, only slightly tapering distally, with many long microtrichia on c. basal two thirds of length on outer surface, apically rounded with very small setulae, some crowded at extreme tip, with one or few larger setulae on subapical part of inner surface, with tuft of short to medium-sized setulae on very short cap-like, slightly convex sclerite at base of inner surface, often a moderately large setula located near tuft; subepandrial process ( Fig. 20 ) moderately slender, with large but not dense setulae; gonostylus tumid and rounded distally, with rather large setulae and some smaller posterior ones, without scabrous or pustulose zone, subtended by a simple sheathing lobe; aedeagus ( Fig. 22 ); membranous surface of bulb with six to ten invaginated, subconical sclerotized teeth of various sizes; cercus ( Fig. 19 ) densely microtrichose, except anteriorly, not much broadened near mid-length, but slightly gibbous before anterior extremity, which forms a simple, anteriorly directed, slightly narrowed papilla bearing minute setulae, in contrast to large setulae on most of length of cercus.

Dimensions. Total length 3.1–3.5 mm; length of thorax, 1.6–1.7 mm; length of wing, 4.0– 4.3 mm.

Distribution. New South Wales: mainly mountainous districts, but recorded for North Coast (Hungry Head). Victoria: widely distributed as far west as Grampians National Park. Tasmania: probably widely distributed. Map references 3L, 4L, 4N, 5L, 5N, 5O, 6K, 6L, 7J, 7K, 8I ( Fig. 4 ).

Notes

Among the species with predominantly pale fore tibia and no sexual dimorphism of the tibiae, males of P. inserta are distinguished by the form of the cercus, which lacks distinctive armature, the distally rounded gonostylus, which lacks a scabrous or pustulose zone, and by the presence of invaginated conical teeth on bulb of the aedeagus ( Figs 21, 22 ). Nothing approaching these structures has been observed in other species.

The specific epithet is a Latin adjective referring to the invaginated teeth inserted in the bulb of the aedeagus.

Figures

Figure 4. Reference map for distribution of Pentachaeta species in eastern Australia. Numbers in each rectangle (2° longitude by 2° latitude) are numbers of recorded species. Map references are given under Distribution for each species.

Figures 18–22. Pentachaeta inserta, male, Mount Wilson; (18) pair of surstyli, posteroventral view; structures on inner surface of basal half seen through transparency; scale = 0.2 mm; (19) pair of cerci, oblique ventral view; setulae shown only on left cercus; scale = 0.2 mm; (20) left gonostylus, subepandrial process, and associated structures; scale = 0.1 mm;(21) bulb of aedeagus, left lateral view, showing invaginated sclerotized teeth; scale = 0.1 mm. Pentachaeta inserta, male, Belgrave; (22) left lateral view of aedeagus; scale = 0.2 mm. ab, aedeagal bulb; as, articulating sclerite; bp, basiphallus; dp, distiphallus; eh, sclerotized extension of hypandrium; g, gonostylus; il, inner lobe of gonostylus; pl, posterolateral extension of basiphallus; sp, subepandrial process; ss, minutely scabrous sclerite of bulb.