Riekoleon squamosus Machado, 2020

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 : 311-314

Riekoleon squamosus Machado , new species

( Figs. 162 , 167–168 )

http://zoobank.org/NomenclaturalActs/ B2A20367-56F5-4A8F-8870-A5A377BB241C

Diagnosis. Legs elongate; wings narrow with numerous brown marks; tibial spurs reaching apex of T1; body mostly brown; pterothorax pleura and abdomen bearing scale-like setae.

Description. Lengths: forewing: 18–19 mm; hind wing: 17–18 mm.

Head ( Figs. 167a, c ): Labrum pale but brown in some darker specimens, set with a line of elongate setae. Clypeus pale with a thin central longitudinal dark brown line, and margin between clypeus and frons dark brown in some specimens; set with few elongate black setae and some short pale setae. Frons ventral margin pale with a thin central longitudinal dark brown line, remaining areas dark brown; covered with short white setae. Gena pale with irregular dark brown marks, and some short black setae. Vertex anteriorly pale but posteriorly dark brown; covered with short black setae. Ocular setae absent. Antennae clubbed; elongate, about twice longer than pronotum; distance between antennae wider than scape width; most segments brown with a pale ring at distal margin, three subapical flagellomeres pale, but apex entirely dark brown; torular membrane pale; flagellomeres almost as long as wide at base, apical ones much wider than long; all segments set with short black setae. Mandible pale, with tip darker. Palpi, maxillary and labial pale with distal segments brown (some specimens with irregular brown marks); apical labial palpomere fusiform, palpimacula opening oval-shaped, located medially.

Thorax ( Fig. 167c ): Pronotum longer than wide; posterior margin wider than anterior; subapical furrow present; mostly pale except for some dark brown areas: a longitudinal medial line (broad before furrow but thin after it), two sinuous lines and lateral margins extending to furrow, two marks after furrow, and small rounded spots at setal base; beset with short thickened black setae and few long and thickened setae. Mesonotum mostly dark brown, with some pale areas as follows: a longitudinal medial line on posterior half of prescutum, two large pale marks, enclosing a longitudinal dark line, near midline and a rounded spot at wings base on scutum, and posterior margin of scutellum; covered with short thickened black setae. Metanotum dark brown with irregular small pale marks in some specimens, with three small groups of setae: one at prescutum and two at posterior margin of scutum, those setae are short, thickened, and with apex rounded and enlarged. Pterothoracic pleura dark brown and totally covered with short thickened black setae with tip enlarged; Miller’s organ present.

Wings ( Fig. 167d ): Rather narrow with tip acute; anterior Banksian line 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 mostly hyaline but with numerous irregular brown marks at costal area base, subcostal area basal half, before pterostigma, posterior margin, apex, and some crossveins; pterostigma white; CuA fork near RP origin; four to five presectoral crossveins with distal ones connected by irregular longitudinal crossveins in some specimens; subcostal veinlets simple; posterior area narrower than prefork area. Hind wing membrane mostly hyaline except for two large brown marks around pterostigma, a large brown mark at rhegmal area and small brown marks around prefork crossveins and tip; pterostigma white; MP fork located near RP origin; subcostal veinlets simple; one presectoral crossvein, except for one specimen with two on left wing.

Legs ( Figs. 167a, c ): All pairs of legs, femur elongate (> 3.5x length of coxa); tibia slightly longer than femur but longer than tarsi; tibial spurs extending to T1 apex; T1 to T4 about same size, T5 more than twice longer than T1; femur and tibia broad, specially femur apically; claws shorter than half of T5 length. Proleg sense hair absent; tibia with antennal cleaning setae ventroapically; all segments dark brown except for coxa internally and base of tibia pale; all segments covered with short black setae, coxa external margin covered with short thickened setae, femur and tibia with long thickened setae. Mesoleg similar to proleg, except for femur without long thickened setae. Metaleg with femur and tibia slightly longer than in mesoleg; colour pattern similar to mesoleg, except for femur and tibia pale with tip dark brown; femur covered only by short thickened setae, and tibia with short black setae ventrally, almost glabrous dorsally.

Abdomen ( Fig. 167b ): Mostly dark brown with scattered pale marks, mainly on medial area of sternites and distal margin of tergites. Four basal tergites and three basal sternites entirely covered by short black thickened setae with apex enlarged, remaining segments with thickened setae.

Male Terminalia: Unknown.

Female Terminalia ( Figs. 168 a–b): Ectoproct posterior margin rounded covered with thin elongate setae. Lateral gonapophyses rounded, much smaller than ectoproct, set with some elongate setae, and few short and thickened setae ventrally. 7 th sternite small, with distal margin rounded in ventral view; covered with long black setae. Pregenital plate weakly sclerotized, small, and rectangular in ventral view. Posterior gonapophyses broad, long, covered with many long black setae and with many cavisetae apically. 9 th tergite with a long membranous digitiform process. Anterior gonapophyses a large plate covered with long setae. Ventral membrane gonapophyseal plates absent.

Distribution ( Fig. 162 ). Australia: NSW, QLD. Known from scattered records in southeastern Queensland and eastern New South Wales.

Adult activity period. Records for November to January.

Biology. Unknown, larva unknown.

Etymology. squamosus (from Latin squamosus, scaly), in reference to the short, scale-like, setae that cover much of the thorax and abdomen.

Name-bearing type. Riekoleon squamosus : Holotype (by present designation), female, AMSA. AUSTRA- LIA: Queensland: foot of Blackbutt Range, 13 km E of Blackbutt, 26: 53.3S– 152: 12.8E, 9.jan.2002, Moulds, Hill et al. Condition: pinned; good; no parts missing.

Paratypes (7♀). AUSTRALIA: New South Wales: Canowindra: i.1956 (1♀, MVM, pinned); Deriah Ab- original Area : 23 km E of Narrabri, - 30.345S– 150.014E, 10.xi. 2009, 460m, Ooline, D.R. Britton & J. Recsei, SEVT2009012, [at light] (1♀, AMSA, pinned); Moema National Park : 36.5 km NE of Narrabri, - 30.064S– 149.965E, 13.xi. 2009, 355m, Semi evergreen vine thicket, D.R. Britton & J. Recsei, SEVT2009029, [black light bucket] (1♀, AMSA, pinned); 18 km N of Temora; 26.xii.1992, M.S. & B.J. Moulds (2♀, AMSA, pinned) ; Queensland: Barakula State Forest: 28.5 air km NNW Chinchilla , 26.49661°S– 150.52354°E, R Machado, MV light, 19.xii.2015, AustRM#04 (2♀, TAMU, 100% ETOH) .

Comments. The male of R. squamosus is unknown, so the state of its ectoproct, which contains diagnostic traits for Riekoleon , remains unknown. However, the species is clearly placed in Riekoleon phylogenetically ( Fig. 4 ) on the basis of female characters, particularly the terminalia and the form of the legs, pronotum, and wings. The scalelike setae covering parts of the thorax and abdomen are apparently unique among Australian antlions and easily separate R. squamosus from all other species. The species was included in the molecular phylogeny of Machado et al. (2019) as “ Riekoleon sp.”

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 167. Riekoleon squamosus sp. nov.: a) head, anterior; b) abdomen base, lateral (note scale-like setae); c) head and thorax, dorsal; d) wings, dorsal.

FIGURE 168. Riekoleon squamosus sp. nov.: female: a) terminalia, lateral; b) terminalia, ventral (note pregenital plate hidden beneath sternite). Scale bars = 1mm.