Clastobasis sritribuana Amorim & Oliveira sp. n.

(Fig. 40A–D)

https://singapore.biodiversity.online/species/A-Arth-Hexa-Diptera-000801

urn:lsid:zoobank.org:act: 9446F6A2-1A82-4336-BB48- 0FAAB44C26E8

Diagnosis

Head and most of thorax dark brown, only shoulders whitish-yellow. Flagellomeres 1–8 annelate, yellow on anterior half, brown on distal half. Coxae whitish, no marks, femora and tibiae cream-yellow. Abdominal tergites 1–4 and 6 brown, tergites 3–5 cream-yellow, sternite 1–2 and 6 brown, sternites 3–5 cream-yellow with slender brownish lateral marks.

Clastobasis_sritribuana _ ZRCBDP 0137106_hapZRCBDP0137106_SMH_holotype [19: A, 28: T, 52: C, 70: G, 110: G, 112: A, 139: C, 145: C] tttagcttcaacaattgcAcacgcag gTgcttctgttgatttagcaattttCtctttacatttagctggGatttcctcaattttag gagctgtaaattttattactactGtAattaatatacgagctccaggaatttcCtttg aCcgaatacctttatttgtttgatcagttctaattactgctgttttattattactttcattac cagtattagcaggagctattactatacttttaacagatcgaaatttaaatacttctttct ttgatccagcaggaggaggagatcctattttatatcaacatttattt

Description

Female (Fig. 40A). Wing length, 2.76–2.98; width, 0.94–0.99 (n=2). Head. Vertex brown, with scattered setae posteriorly to ocelli, an irregular crown of longer setae on occiput around eyes. Mid ocellus present, placed at posterior end of frontal furrow, less than half of diameter of lateral ocelli, lateral ocelli nearly touching eye margin. Frons, face, and clypeus yellow. Frons devoid of setae, frontal furrow complete, reaching mid ocellus; face slender, bare, entirely separated from clypeus; clypeus large, truncate ventrally, entirely covered with setae. Scape twice length of pedicel, yellowish. Scape with a subapical crown of setulae and a distal crown of stronger setae; pedicel with a single distal crown of setulae and larger setae, dorsally a conspicuous seta. Flagellomeres 1–8 yellowish with a brown distal band, flagellomeres 9–14 light brown. Maxillary palpus yellowish, five palpomeres, basal one weakly sclerotized, bare, palpomere 2 short, with dorsal setae, palpomere 3 well-developed, with a well-defined sensorial pit opening laterally on basal third and scattered setulae on dorsal face, about 4× length of palpomere 2; palpomere 4 elongate, weakly sclerotized, slightly longer than palpomere 2, with scattered setulae dorsally; palpomere 5 more than twice palpomere 4 length, slender, weakly sclerotized, with scattered dorsal setulae. Labella yellow, large, with a pair of pseudotracheae. Thorax. Scutum dark brown, scutellum brown. Scutum covered with scattered short setae, some stronger supra-alars and prescutellars; a pair of strong scutellar bristles, a pair of strong setae more externally and 2–4 setulae laterally. Pleural sclerites brown, membrane whitish. Basisternum with wide dorsoposterior arms. Antepronotum wide, with five bristles and additional small setae; proepisternum well-developed, with three bristles and two setulae on ventral half. All remaining pleural sclerites bare except for laterotergite, with about 35 setae and setulae. Mesepisternum wide on ventral half, reaching ventral margin of pleura, mediotergite long, only gently curved. Haltere whitish, setose. Legs. Coxae whitish-yellow, distal margin of mid and hind coxae, and mid and hind trochanters with dark brown markings, hind coxa with a dark brown mark on basal fifth. Mid and hind femora, tibiae and tarsi light brownish yellow [both fore legs broken]. Fore coxa with fine setae covering entire frontal and lateral faces, and a few strong bristles on distal margin; mid coxa covered with setae on frontal face and on distal half of lateral face, a few strong bristles on distal margin; hind coxa with setae restricted to basal fifth of frontal face, a few strong bristles on distal margin. Mid and hind tibiae and tarsi with irregularly distributed trichia; tibia with two irregular rows of short bristles dorsolaterally, hind tibia with a pair of irregular dorsolateral rows and a dorsal row of short bristles. Mid and hind tarsomeres 1 and 2 with a few short bristles. Tibial spurs yellow, outer spurs about 5× tibial diameter at apex, outer spur over 1.5× longer than inner spur. Tarsal claw with a small proximal tooth and a large, blunt medial tooth. Wing (Fig. 40B). Membrane without macrotrichia, translucent, with a light brownish-yellow tinge. C ending at apex of R 5. Sc complete, ending at C in wing basal fourth, weakly sclerotized distally; sc-r not sclerotized. R 1 short, 0.88× r-m length, reaching C at mesal third of wing; first sector of Rs nearly transverse, short; R 5 short, reaching C before level of tip of M 2, straight except very distally; r-m curved on basal third, more than 6× length of first sector of Rs. M 1+2 shorter than length of r-m; M 1 and M 2 more than 5× length of M 1+2; M 1 gently curved posteriorly on distal half, M 2 curved anteriorly on distal half, fading on distal fourth, line of setae reaching margin. M 4 gradually curved posteriorly, interrupted at its very base, not connecting to CuA. CuA gently sinuous midway to apex. Veins bR, R 1, R 1 and R 5 with ventral and dorsal setae, M 1+2, M 1, M 2, M 4 and CuA with only dorsal setulae; Sc, first sector of Rs and CuP bare. Abdomen. Tergites 1–4 brown, tergite 5 yellowish laterally, brown medially, tergites 6–7 brown; sternites 1–2 brownish, sternite 3–5 cream-yellow with brown lateral margins (extension of brown area varying between individuals), sternites 6–7 brown. Sternite 1 strongly modified, U-shaped, displaced posteriorly, fit into a large incision on anterior half of sternite 2. Terminalia (Fig. 40C, D). Terminalia brownish. Sternite 8 wide, with a pair of overlapped lobes at each side, widely covered with microtrichia, setae restricted to lobes and posterior margin. Sternite 9 complex, with two pairs of weakly sclerotized elongated lobes, curved sclerotized bands beneath posterior lobe, medial anterior apodeme of vaginal furca not visible. Tergite 8 large, with a pair of projections on each side of posterior margin, mostly covered only by microtrichia, setation restricted to lateroposterior lobes. No evidence of tergites 9 and 10, possibly fused indistinctly to tergite 8. Cerci very modified into a pair of lobes connected to each other medially on anterior end, entirely devoid of microtrichia, short, strong spine-like setae at apex of each lobe. A pair of long apodemes extending anteriorly from each side of anus may correspond to a modified sternum 10.

Male. Unknown.

Material examined

Holotype: female, ZRCBDP 0137106, Bukit Timah Forest (BT07), old secondary forest, 15.nov.16, MIP leg. (slide-mounted).

Paratype (female): ZRCBDP 0047849, Nee Soon (NS1), swamp forest, 26.jun.13, MIP leg. (website photo specimen, slide-mounted).

Additional sequenced specimen: ZRCBDP 0138569, Bukit Timah Forest (BT06), maturing secondary forest, 15.nov.16, MIP leg.

Etymology

The species epithet refers to Sri Tri Buana, the official title of the Srivijayan (a Buddhist thalassocratic empire in Southeast Asia during the 7th to 12th centuries) prince Sang Nila Utama. He was the founder of the Kingdom of Singapura (Kerajaan Singapura; est. 1299). Sang Nila Utama is said to have landed on Temasek (the island of Singapore) on a hunting trip, having supposedly seen a lion. Taking this as an auspicious sign, he founded the Kingdom based on the settlement hence called Singapura, in one of the standing interpretations considered to come from the Sanskrit “Lion City”. The noun is used in apposition.

Remarks

This species clearly differs in color pattern from the other two species of Clastobasis described here. Most species of Clastobasis fit in the yellowish color pattern seen in C. bugis sp. n. and C. oranglaut sp. n., but there are some species of Clastobasis in Japan that share this general brown color pattern of C. sritribuana sp. n. (KURINA 2020). We have two haplotypes for this species and no delimitation conflicts.