Riekoleon striatus (New, 1985)

Machado, Renato Jose Pires & Oswald, John David, 2020, Morphological phylogeny and taxonomic revision of the former antlion subtribe Periclystina (Neuroptera: Myrmeleontidae: Dendroleontinae), Zootaxa 4796 (1), pp. 1-322 : 314-317

Riekoleon striatus (New, 1985) , new combination

( Figs. 162 , 169–170 )

http://zoobank.org/NomenclaturalActs/ E503ECD8-C8E0-4E31-98D2-AEF8401D7B90

Austrogymnocnemia striata New, 1985:18 (OD); New 1996:68 (cat); Stange 2004:100 (cat); Oswald 2018 (cat). Austrogymnocnemia emmae New 1985b:26 (OD); New 1996:67 (cat); Stange 2004:99 (cat); Oswald 2018 (cat). new syn-

onym.

Diagnosis. Forewing: first fork of RP in proximal half of wing, dark mediocubital line interrupted (not continuous); ocular setae present; tibial spurs absent; male ectoproct with ventral margin straight; female posterior gonapophysis wider than long; female anterior gonapophysis a small plate.

Description. Lengths: forewing: 21–23 mm; hind wing: 18–21 mm.

Head ( Figs. 169 a–b): Labrum pale, with a line of elongate setae. Clypeus pale, with few elongate pale setae. Frons dark brown with ventral corners yellow; covered with short black setae. Gena pale. Vertex raised; with posterior margin elongate (area above antennae broader) in anterior view pale with two short curved transverse dark brown marks laterally and a rounded central dark spot; in dorsal view mostly pale with two central perpendicular dark brown marks; set with some short black setae. Ocular setae white and elongate. Antennae clubbed; elongate, about twice longer than pronotum; distance between antennae wider than scape width; in general, dark brown except for scape and pedicel mostly pale; torular membrane pale; flagellomeres almost as long as wide at base, apical ones much wider than long; all segments set with short black setae, except for scape and pedicel, with white setae. Mandibles pale to brown, with tip black. Palpi, maxillary and labial pale; apical labial palpomere fusiform, palpimacula opening oval-shaped, located medially.

Thorax ( Fig. 169b ): Pronotum wider than long; posterior margin wider than anterior; subapical furrow present; mostly pale except for some dark brown areas as follows: a broad medial longitudinal line, two sinuous lines connected to the central line anteriorly, two lateral sinuous line on posterior half; beset with short black setae and few long black setae on borders. Mesonotum mostly dark brown with two pale marks at prescutum, some irregular pale lines at scutum, and scutellum marginally pale; covered with short black setae. Metanotum mostly dark brown, except for irregular pale areas mostly around midline and posterior margin of scutellum, set with few short black setae. Pterothoracic pleura dark brown; covered with white setae and some black setae on anterior segments; Miller’s organ present.

Wings ( Fig. 169c ): Rather narrow with tip acute; anterior Banksian lines present in both wings; posterior absent; veins mostly dark brown, but some veins intercalated with white spots, beset with short black setae. Male pilula axillaris present. Forewing membrane hyaline with some large brown marks at tip, posterior margin, mediocubital area, and beneath pterostigma; CuA fork located near RP origin; four presectoral crossveins with the last ones connected by short veinlets; subcostal veinlets simple; posterior area narrower than prefork area. Hind wing membrane mostly hyaline except for some irregular brown marks at tip and rhegmal area; MP fork located near RP origin; subcostal veinlets simple; one presectoral crossvein.

Legs ( Figs. 169 a–b): All pairs of legs, femur elongate (> 2.5x length of coxa); tibia and femur about same size, but longer than tarsi; tibial spurs absent; T2, T3 and T4 about same size, T1 slightly longer than T2, T5 slightly longer than T1; claws about half of T5 length; coxa, trochanter, femur and tibia set with short white setae and scattered long white setae at tibia; femur, tibia and tarsi set with black setae, and scattered long black setae; T5 ventrally with two rows of thick, long, black setae. Proleg sense hair absent; tibia with no antennal cleaning setae; coxa and trochanter internally pale but externally dark brown, femur dark brown with anterior surface base pale, tibia with three brown marks dorsally but remaining areas pale; tarsi dark brown, with base of T1 pale. Mesoleg with colour pattern similar to proleg, except for tibia slightly darker. Metaleg with femur and tibia slightly longer than in other legs; colour pattern similar to anterior legs, except tibia pale with tip dark brown.

Abdomen: Mostly dark brown with scattered pale marks, mainly on sternites medial area. Beset with short black setae.

Male Terminalia ( Figs. 170 a–c): Ectoproct in lateral view with ventral margin straight and longer than dorsal margin; set with elongate black setae. 9 th sternite with posterior margin curved in ventral view; and covered with short black setae. Gonarcus broad and arched; with anterior margin acute in lateral view. Mediuncus small, a sharp triangle lobe on gonarcus medial area in posterior margin. Paramere large, with ventral margin more sclerotized in lateral view; and semi triangular in ventral view.

Female Terminalia ( Figs. 170 d–e): Ectoproct posterior margin rounded covered with thin elongate setae. Lateral gonapophyses rounded, smaller than ectoproct, covered with elongate setae. 7 th sternite small, with distal margin concave in ventral view; covered with long black setae. Pregenital plate semi triangular in ventral view. Posterior gonapophyses large, wider than long in ventral view, set with elongate setae but apex covered with numerous cavisetae. 9 th tergite with a long membranous digitiform process. Anterior gonapophyses present, a small rounded plate covered with short setae. Ventral membrane gonapophyseal plates present.

Distribution ( Fig. 162 ). Australia: QLD*, SA, WA. Known from sparse records across mainland Australia; one of only three Riekoleon species (with R. edwardsi and R. rudda ) currently reported from both western and eastern Australia.

Adult activity period. Records for September to January.

Biology. Unknown, larva unknown.

Name-bearing types. Austrogymnocnemia striata : Holotype (by original designation), female, SAMA, examined. Type locality: Australia, Western Australia, Gill Pinnacle (mountain), Mural Crescent. From original description: “ Holotype, ♀, Western Australia, Gill Pinnacle, Mural Crescent, 3.xi.1963, P. Aitken, N. B. Tindale ( SAM)”. Condition: good; terminalia dissected.

Austrogymnocnemia emmae : Holotype (by original designation), male, AMSA, high-resolution images examined. Type locality: Australia, South Australia, Flinders Ranges (mountains), Wilpena Pound. From original description: “ Holotype, ♂, South Australia, Flinders Ranges, Wilpena Pound, 18.i.1976, M.S. and B.J. Moulds (AM)”. From New (1996): “Type data: holotype AM ♂. / Type locality: Wilpena Pound, Flinders Ranges, SA”. Condition: good; apical half of left hind wing missing; terminalia dissected.

Additional material examined (2♂, 2♀). AUSTRALIA: Queensland: Carnarvon National Park: Rangers Station, Mt Moffatt Sect , 25 o 01’06’’S– 147 o 57’08’’E, 25.xii. 2005, 720 m, G & A Daniels (1♀, QMBA) ; Charleville –Bolton Road , 70 km SE of Charleville, 26 o 52’S– 146 o 35’E, 29.ix. 1991, 300 m, mv lamp, G Daniels (1♂, QMBA) ; Cudmore National Park: near Homestead , - 22.9419S– 146.3786E, 28.x. 2010, 320m, heath-shrubland G. & B. Williams, ENT.QLD.2010.09 [at light] (1♀, AMSA) ; Western Australia: South Perth : 31 o 58’S– 115 o 51’E, 18.i.1985, P. Hutchinson (1♂, QMBA) .

Comments. New (1985b) described R. striatus from two specimens (a female holotype and male paratype) and Austrogymnocnemia emmae from a single male specimen. After studying these types, and examining additional specimens, we here synonymize A. striatus and A. emmae (treating the former as the senior synonym, acting as first reviser) and transfer the species to Riekoleon . While male specimens are generally paler than female specimens, as noted by New, other characters—e.g., the shapes of the pronotum, flagellomeres, and wings, the relative sizes of the leg segments, the presence of ocular setae, and the markings on the head—support synonymization. We were not able to confirm any significant differences in the terminalia of the two males (one A. striatus and one A. emmae ) examined by New, and we interpret the holotype of A. emmae here as a slightly smaller and paler male specimen of R. striatus . Within Riekoleon , R. striatus is easily distinguished by its short pronotum and the presence of ocular setae. For phylogenetic relationships see Fig. 4 .

Figures

FIGURE 4. Strict consensus tree of morphology-based parsimony analysis of species belonging to the former subtribe Periclystina (ingroup, names in black), and outgroups (names in red). Former Glenoleon species are shown on blue branches, former Austrogymnocnemia species on green branches. Numbers above branches are Bremer support values; numbers below branches are bootstrap values (shown where>50%).

FIGURE 162. Distribution of Riekoleon species (part).

FIGURE 169. Riekoleon striatus: a) head, anterior; b) head and thorax, dorsal; c) wings, dorsal.

FIGURE 170. Riekoleon striatus: male: a) terminalia, lateral; b) genitalia, posterior; c) genitalia, lateral; female: d) terminalia, lateral; e) terminalia, ventral. Scale bars = 0.5 mm.