Diplectrona Westwood, 1839

Wells, Alice & Contents, Arturs Neboiss Table Of, 2018, Australian Diplectroninae reviewed (Insecta: Trichoptera), with description of 21 new species, most referred to a new genus, Zootaxa 4415 (1), pp. 1-44 : 6-7

Diplectrona Westwood

( Figs 1–48 )

Diplectrona Westwood 1839 , 49. Type species, Diplectrona felix McLachlan 1878 , under Plenary Powers, ICZN Decision 758 [1966]. [See Fischer (1963a, 1972) and Morse (2017) for full taxonomic literature on Diplectrona and its included species.]

Diemeniluma Neboiss 2003 , 71. Type species, Diplectrona tasmanica Jacquemart 1965 , by original designation. New synonym.

Diagnosis. In the Australian hydropsychid fauna, Diplectrona resembles Austropsyche and Arcyphysa gen. nov. in having fork 2 in both wings usually sessile, and in the hind wing Sc and R distally curved towards the costal margin, but is distinguished from Arcyphysa in having on the dorsal head the anterolateral setal warts undivided or incompletely divided; and from Austropsyche in having the anterolateral warts at most with an incomplete, indistinct, median suture, not fragmented posteriorly; and coxopodites of male gonopods simple, without mesal processes.

Description. Medium-sized caddisflies. Head ( Figs 17–21 ) dorsally with 5 setal warts, anterolateral warts wider than long, undivided or incompletely and indistinctly divided, crowded by pair of large posterior warts. Maxillary palpi ( Figs 2 , 27–28 ) with segments 2 and 3 equal length, 4 slightly shorter, segment 5 exceeding length of 2+3+4. Antennae with at least distal segments bearing sutures and tufts of setae, giving crenate appearance ( Figs 25–26 ). Midtibiae and tarsi not dilated. In both pairs of wings fork 2 sessile ( Figs 1 , 22, 24 ) or very short ( Fig. 23 ); forewings each with vein A1+2+3 curved, cell ac lanceolate to subtriangular; hind wings each with Sc and R with pronounced posterior curvature distally before wing margin. Abdomen with pair of filaments laterally on segment V ( Figs 30–31 ), length variable; in male reticulate-walled internal sacs ( Fig. 29 ) spherical to elongate-ovoid. Male genitalia ( Figs 3–12, 14–16 , 32–43, 45–46) with midapicolateral margin of segment IX often extended into paired distinct triangular lobes (‘phallic guides’ or ‘clasper guides’ of Ross & Morse, unpublished MS); phallus with or without spines or spicules distally. Female terminal abdomen ( Figs 13 , 44, 47–48 ) with sternite VIII comprising two sclerites, usually separated ventromesally, produced apicolaterally, apical tubercles on segment X small.

Remarks. Continued separation of Diemeniluma from Diplectrona is unsupported. Diemeniluma was erected on the basis of rather weak features. The key characteristic of absence of anteromesal wart on the vertex of the head was erroneous as there is a small round wart between the two large, undivided anterolateral warts ( Figs 18, 19 )— the arrangement of head warts in Diemeniluma closely resembles that seen in a specimen of the type species, Diplectrona felix ( Fig. 17 ). The female characteristics of Diemeniluma as given by Neboiss (2003) —abdominal 'sternite VIII entire, not divided ventromesally; segment IX without lateral scleritic cavity, sternite three-lobed'— have not been confirmed in the genitalic preparation of the female identified, as that of D. tasmanica cannot be located in the NMV collection. However, a single female in ANIC, tentatively associated with a male of D. tasmanica , does show at least some slight midventral separation of sternite VIII ( Fig. 44 ); the female is not known for the second species, D. serrula ( Neboiss 2003) . The nature of the triangular midapicolateral structures on segment IX of male D. inermis ( Banks 1939) , and D. spinata ( Banks 1939) (the ‘phallic guides’) becomes apparent when D. tasmanica is viewed laterally. With greater or lesser fusion of segments IX and X these become more closely associated with tergite X as in D. tasmanica (compare Figs 3, 5 and 42, 43).

Figures

FIGURES 1–9. Diplectrona Westwood 1839, diagnostic features. 1–5, D. inermis (Banks 1939; (NSW, Leura, ‘Bridle Vale’ [PT-1032]), ♂: 1, right fore- and hind wings, dorsal; 2, maxillary palp; 3, genitalia, ventral; 4, apex of phallic apparatus, left lateral; 5, genitalia, left lateral. 6–7, D. inermis (NSW, Minnamurra Falls, W of Kiama [PT-1035]), ♂ genitalia: 6, ventral; 7, left lateral. 8–9, D. inermis (Vic., Wilson’s Promontory, Waterloo Bay [PT-1011]), ♂ genitalia: 8, ventral; 9, left lateral. Scale bar = 1mm.Abbreviations:ac= anal cell;alp = apicolateral process;A 1+2+3 =fused analveins A 1, A 2, A 3;dc = discoidalcell;cox = coxopodite; fI, fII,fIII,fIV,fV = forks I–V; mc = mediancell; har = harpago; ph= phallic apparatus; ph sp= spines of phallic apparatus; IX, X = abdominal segments IX, X.

FIGURES 10–16. Diplectrona Westwood 1839, diagnostic features. 10–12, D. spinata (Banks 1939; holotype), ♂ genitalia: 10, ventral; 11, left lateral; 12, dorsal. 13, D. inermis (NSW, Leura, ‘Bridle Vale’ [PT-1057]), ♀ terminal abdominal segments, left lateral. 14–16, D. willandi sp. nov. (holotype), ♂ genitalia: 14, ventral; 15, left lateral; 16, dorsal. Abbreviations: ph = phallic apparatus; VIII, IX, X = abdominal segments VIII, IX, X.

FIGURES 17–31. Diplectrona Westwood 1839 spp., diagnostic features. 17–21, heads, dorsal: 17, D. felix McLachlan 1878 (France, Pyrenees), ♂; 18–19, D. tasmanica Jacquemart 1965 (Pine River, Cradle Mountain Road, Tas.): 18, ♂, and 19, ♀; 20, D. inermis (Banks 1939; NSW, Leura, ‘Bridle Vale’), ♂; 21, D. spinata (Banks 1939; Qld, Springbrook), ♂. 22–24, ♂ right wings, dorsal: 22, D. castanea (Kimmins 1953; Tas., Nelson River at base of Nelson Falls [TRI-15004]), right fore- and hind wings, dorsal; 23, D. spinata (Qld, Branch Creek, Brisbane Riv. Catchment [TRI-30501]), right forewing, dorsal; 24, D. willandi sp.nov. (holotype), right fore- and hind wings, dorsal. 25–26, sectionsof ♂ antennae:25, D. felix; 26, D. inermis. 27– 28, ♂ maxillary palps: 27, D. castanea; 28, D.spinata. 29, D. inermis, ♂ reticulate-walled internal sacs of abdominal segments VIand VII, ventral.30, D. felix, ♂ right lateral filament on abdominal segment V, ventral.31, D.inermis, ♂ leftlateral filament on abdominal segment V, ventral. Scale bars = 2 mm. Abbreviations: ac = anal cell; alw = anterolateral wart; amw = anteromesal wart; A 1+2+3 = fused anal veins A 1, A 2, A 3; dc = discoidal cell; mc = median cell; pw = posterior wart.

FIGURES 32–48. Diplectrona Westwood 1839 spp., genitalia diagnostic features. 32, D. castanea (Kimmins 1953), (Tas., Nelson River at base of Nelson Falls [TRI-15004]), ♂, ventral; 33–34, D. lyelli Neboiss 1977 (synonym of D. castanea; paratype; Tas., Hellyer River Gorge [PT-1043]), ♂ segments IX and X and gonopods: 33, left lateral, and 34, apex of phallic apparatus, left lateral. 35–37, D. inermis (Banks 1939), ♂: 35, holotype, ventral; 36, holotype, left lateral; 37, Vic., Wilson’s Promontory, Waterloo Bay[PT-1011], ventral. 38–41, D.spinata (Banks 1939), ♂: 38, NSW, BarringtonTops,Upper Williams R. [PT-1835], ventral; 39–40, Qld, Brisbane [TRI-39514]: 39, left lateral, and 40, ventral; 41, Qld, Springbrook [TRI-39496], ventral. 42–44, D. tasmanica Jacquemart 1965 (Tas., Pine River, Cradle Mountain Road; ANIC): 42–43, ♂ genitalia: 42, ventral, and 43, left lateral; 44, ♀, terminal abdominal segments, ventral. 45–46, D. willandi sp. nov. (Qld, Fishery Falls), ♂: 45, ventral;46, left lateral.47–48, D.spinata(Qld, Springbrook[TRI-39426]),♀ terminal abdominal segments:47, ventral;48, left lateral.