Review of the Australian Genus Pentachaeta (Diptera: Heleomyzidae), with Descriptions of Nine New Species McAlpine, David K. Records of the Australian Museum 2014 2014-10-22 66 5 247 264 McAlpine, 2014 McAlpine 2014 [996,1233,151,178] Insecta Heleomyzidae Pentachaeta Animalia Diptera 11 257 Arthropoda species skusei sp. nov.   Figs 26–29   Type material.  Holotype ♂. Victoria: Belgrave, near Melbourne, [probably margin of Sherbrooke Forest, c. 37°53'S 145°22'E],  21.i.1966, D.K.M.( AM K310595). Gluedto card point, postabdomen in genitalia tube on same pin.  Paratypes. Victoria: 2♂♂, Ninks Road, Kinglake,  Jan 1980, B.W.B. ( ANIC).  New South Wales: 1♂, below Govett’s Leap, Blue Mountains,  Dec. 1956, D.K.M.( AM).   Description (male) Resembling  P. edwardsiand related species without sexual dimorphism of tibiae; agreeing with description of that species, except as indicated below.  Colorationgenerally as for genus; details as given for  P. edwardsiexcept as here noted. Fore femur orange-tawny, becoming brownish dorsally (perhaps faded in old typespecimens); fore tarsus with segments 1 and 5 brown or largely brown, segments 2 to 4 pale tawny-yellow; mid tarsus tawny yellow, indistinctly brownish distally in faded specimens; hind tarsus dark brown.  Abdomen. Surstylus ( Fig. 26) ovate-lanceolate, distally gradually tapering to obtuse apex, outer surface extensively microtrichose, also with scattered short but rather stout setulae, which may be more numerous on posterior part of outer surface, apical part of inner surface with few setulae of variable size and marginal group of minute setiferous tubercles, at base of inner surface fascicle of short, stout setulae, either not arising from a common prominence, or on very slight prominence; subepandrial process ( Fig. 29) with numerous stout setulae towards apex and on inner surface; apex of gonostylus with three or four large setulae and sometimes few much smaller ones, with flat or slightly concave posterodistal densely pustulose zone; bulb of aedeagus without invaginated teeth; cercus ( Figs 27, 28) narrowly extended posteriorly, much broadened across base of anterior lobe, with pair of anterior lobes strongly divergent, at broadest part with prominent dorsal (and thus partly concealed) setulose tubercle ( Figs 27, 28), on exposed ventral surface with extensive armature of large setulae, becoming sparser and finer on anterior lobe.  Figures 26–29.  Pentachaeta skusei, male, Govett’s Leap (26)pair of surstyli, posteroventral view; setulae shown only on left surstylus and on prominence of inner basal surface of right surstylus (latter seen through transparency); scale = 0.2 mm.  Pentachaeta skusei, Belgrave (27)epandrium with cerci, setulae shown only on left cercus and dorsal tubercles; scale = 0.2 mm; (28)medial view of anterior lobe of right cercus; scale = 0.1 mm.  Pentachaeta skusei, Govett’s Leap (29)left gonostylus, subepandrial process and associated parts, lateral view; scale = 0.05 mm. as, articulating sclerite; dt, dorsal setulose tubercle of cercus; eh, sclerotized extension of hypandrium; g, gonostylus; pl, posterolateral extension of basiphallus; sp, subepandrial process.  Dimensions. Total length 3.2 mm; length of thorax, 1.3–1.6 mm; length of wing, 3.4–4.0 mm.   Distribution. New South Wales: Blue Mountains. Victoria: forested areas E and NE of Melbourne. Map references 4L, 7J ( Fig. 4).  Notes   Pentachaeta skuseibelongs among those species without sexual dimorphism of the tibiae and with the fore tibia tawny yellow with brown apex. It differs from other such species in having segments 2 to 4 of the fore tarsus tawny yellow (dark brown in related species). The form of the surstylus ( Fig. 26) is distinctive, though somewhat resembling that of  P. gilliesi, but the male cercus is very different (compare Figs 27and 30). I suspect that the unknown female will be distinguishable from related species by the coloration of the fore tibia and tarsus, as in the male. This species is dedicated to Frederick A. Skuse, the first Dipteraspecialist employed at the Australian Museum. 1966-01-21 AM David K. McAlpine & Glued -37.883335 Melbourne 1178 145.36667 Belgrave 11 257 K310595 1 1 Victoria holotype 1980-01 ANIC Kinglake Ninks Road 11 257 2 2 Victoria paratype 1956-12 AM David K. McAlpine Blue Mountains Govett's Leap 11 257 1 1 New South Wales paratype