Riethia galilei, Trivinho-Strixino & Shimabukuro, 2018

Trivinho-Strixino, Susana & Shimabukuro, Erika Mayumi, 2018, Brazilian Pseudochironomini (Diptera: Chironomidae) Part 2. New Pseudochironomus and Riethia species, Zootaxa 4403 (2), pp. 245-260 : 256-258

Riethia galilei sp. n.

( Fig. 10 )

Type material. Holotype: Male, slide mounted in Euparal, Brazil, AM, Manaus, AM, RF Ducke, Igarapé Ipiranga, 05.iv.2017, leg. GPS, Dantas, (I1-40, LEIA-UFSCar) . Paratypes: 2 male as holotype (I1-41, 42, LEIA-UFSCar).

Derivation nominis. Named in honour of Dr. Galileu Dantas a friend and great researcher of Amazon Chironomidae .

Diagnostic characters. Riethia galilei sp. n. differs from other species of the genus by the combination of the following characters. Male: hypopygium with superior volsella short and hooklike with 2 apical and 2–3 marginal internal setae. Median volsella present. Inferior volsella triangular with 3–4 large marginal semipectinate scales,numerous apically pectinate and non-pectinate setae and 2–3 apical large marginal curved scales.

Description. Male (n = 1).Total length 3.30 –3.84 mm. Wing length 1.78–1.86 mm (2).

Colouration. Thorax white brown with brown vitae; abdomen and legs brown.

Head. Temporal with 10–12 setae. Eye with broad dorsomedial extension. Clypeus with 16–20 setae. Antenna 1.09– 1.21 mm long; AR 1.61 (1). Palpomere 2–5 (1) lengths: 62–69, 87–113, 122–150, 153–225 µm.

Thorax ( Fig. 10a ). 1.06–1.18 mm long. Ac absent; Dc 6–8; Pa 3; Scts 11.

Wings ( Fig. 10b ). Width 0.55 mm. VR 1.18 (1). Brachiolum with two setae. Veins setae on R with 16, R1 with 10 and R4+5 with 10 setae. Squama with 6 setae.

Legs. Spur of fore tibia 58 µm. Tibial combs of mid and hind legs partly fused; mid tibial spur anterior, 75–83 µm, posterior 87–92 µm long; hind tibial spur anterior, 73–80 µm, posterior 91–100 µm long. Lengths and proportions of legs as in Table VI.

TABLE VI. Lengths (in µm) and proportions of Riethia galilei sp. n. male (1).

Hypopygium ( Fig. 10c, d ). Tergite IX without anal point. Laterosternite with two setae Transverse sternapodeme 120 µm long, without oral projections. Phallapodeme near 107 µm long. Gonocoxite 131–138 µm long. Superior volsella short hooklike with four marginal simple setae ( Fig. 10e ). Median volsella with two apical simple setae. Inferior volsella triangular pubescent 103 µm long with 3–4 apical large marginal semipectinate scales, numerous apically pectinate and non-pectinate setae and 2–3 apical large marginal curved scales. ( Fig. 10f ). Gonostylus 197–228 µm long. HR 0.60–0.66.

Figures

FIGURE10. Riethia galilei sp. n. male (a)Thorax.(b)Wing.(c) Hypopygium.(d) Hypopygium, right ventral view, left dorsal view.(e) Superior volsella.(f) Inferior volsella.