Dichaetophora sumatraensis Yang & Gao, 2017

Yang, Jin-Hua, Toda, Masanori J., Suwito, Awit, Hashim, Rosli & Gao, Jian-Jun, 2017, A new species group in the genus Dichaetophora, with descriptions of six new species from the Oriental region (Diptera, Drosophilidae), ZooKeys 665, pp. 121-146 : 130-133

Dichaetophora sumatraensis Yang & Gao sp. n.

Figs 3Q-S , 4Z-D ', 10

Type material.

Holotype ♂ (#03890): INDONESIA: Mt. Kerinci., Jambi, Sumatra, 7.x.2004, MJ Toda (MZB).

Paratypes: same as holotype (1♀: #03891, MZB); same as holotype except for 6.x.2004 (1♀, SEHU).

Diagnosis.

Postocellar setae present; spermathecal capsule somewhat dome-shaped, apically roundish; introvert 2/5 as deep as capsule height (Fig. 10K ); hypandrium without pubescence on caudolateral plate (Fig. 10H ); COI = T and C at sites 142 and 205, respectively; COII = C, T, T, T, A and T at sites 18, 69, 270, 303, 381 and 393, respectively (Table 5 ).

Description.

Head (Figs 3Q, R , 4Z-D '): First flagellomere grayish brown. Dorsolateral tentorial apodemes slightly divergent in basal 2/5 but strongly divergent in distal 3/5; supercervical setae 19-22 per side; postocular setae 20-24 per side. Palpus with one subprominent, lateromedial seta. Cibarium with numerous (> 60) medial and 8-9 posterior sensilla per side.

Wing (Fig. 3S ) slightly fuscous; veins yellowish brown to brown. Halter and stem gray.

Legs (Fig. 3Q ): All femora blackish brown; foreleg coxa, tibia and tarsus (except 5th tarsomere) grayish brown; rest grayish yellow. Apical setae present on foreleg and mid-leg tibiae. Mid-leg first tarsomere as long as total length of four succeeding tarsomeres; hindleg first tarsomere longer than total length of four succeeding tarsomeres.

Male terminalia (Fig. 10A-H ): Epandrium pubescent except for anterior margin, with three dorsal and 11-13 ventral, long setae per side. Surstylus with 9-10 prensisetae caudal margin, 2-3 short spines and medial patch of pubescence on outer surface and ca. 15 recurved spines on inner, caudal portion. Tenth sternite lingulate, slightly curved. Cercus pubescent except for dorsal to caudal margin, with 20-21 long setae; sclerotized, caudoventral bridge of cerci medially with narrowly elongated process. Paramere somewhat triangular in lateral view, apically round, with sensilla on inner surface. Aedeagus apically trilobed, densely hirsute on outer lobes, dorsosubapically with a pair of small, marginally serrated flaps.

Female terminalia (Fig. 10I-K ): Oviscapt valve dorsomedially narrowly extended, with 5-6 lateral and 14-17 marginal, peg-like ovisensilla. Spermathecal capsule without spinules on outer surface.

Measurements (in mm): BL = 2.33 in holotype (1♀ paratype: 2.70), ThL = 1.04 (1.13), WL = 2.17 (2.46), WW = 1.10 (1.00).

Indices: FW/HW = 0.36 (1♀ paratype: 0.40), ch/o = 0.39 (0.33), prorb = n/a (n/a), rcorb = n/a(n/a), orbito = 0.75 (0.78), dcl = 0.72 (n/a), sctl = n/a (n/a), sterno = n/a (0.61), dcp = 0.62 (0.60), sctlp = 0.80 (0.75), C = 1.90 (2.00), 4c = 1.29 (1.34), 4v = 2.18 (2.23), 5x = 2.18 (1.84), ac = 2.37 (2.57), M = 0.79 (0.75), C3F = 0.58 (0.60).

Etymology.

Pertaining to the type locality.

Distribution.

Indonesia (Sumatra).

Remarks.

The last three species somewhat resemble Dichaetophora trilobita sp. n. in having the following morphological characters: wing without distinct, dark cloud; surstylus with medial patch of pubescence on outer surface; sclerotized, caudoventral bridge of cerci with narrow, median process; and oviscapt valve dorsomedially narrowly extended. However, the three species are very hard to distinguish from each other because of their least morphological differentiation. To overcome this difficulty, we employed 19 nucleotide sites of COI and COII genes as molecular diagnostic characters to identify these cryptic species (Table 5 ). Nucleotide substitutions at two of these sites are nonsynonymous, i.e., causing changes of amino acids, and specific to Dichaetophora borneoensis sp. n. (Table 5 ), thus providing more reliable (less changeable) characters for this species.

Figures

Figure 3. Left lateral habitus, head and thorax (dorsal view), wing (left, ventral view), and abdomen (dorsal view). A-D Dichaetophora tirlobita sp. n. (# 03877) E-G D. heterochroma sp. n. (# 03879) H-J D. flatosternata sp. n. (# 04172) K-M D. borneoensis sp. n. (# 03895) N-P D. javaensis sp. n. (# 03892) Q-S D. sumatraensis sp. n. (# 03890). Scale bars: 1.0 mm.

Figure 4. Head (anterior view), postocciput, palpus, and prementum (ventral and lateral view, respectively). A-E Dichaetophora tirlobita sp. n. (# 03877) F-J D. heterochroma sp. n. (# 03879) K-O D. flatosternata sp. n. (# 04172) P-T D. borneoensis sp. n. (# 03895) U-Y D. javaensis sp. n. (# 03892) Z-D D. sumatraensis sp. n. (# 03890). Scale bars: 0.1 mm except for A, F, K, P, U, Z (0.5 mm).

Figure 10. Dichaetophora sumatraensis sp. n. (A-H # 03890 I-K paratype # 03891). A, B Periphallic organs (posterior and posterolateral view, respectively) C surstyli and ventral portions of cerci D tenth sternite (posteroventral view) E-G phallic organs (ventral, ventrolateral and lateral view, respectively) H distal portion of hypandrium (posteroventral view), showing the caudolateral plates not pubescent (red arrows) and the paramedian setae I, J oviscapt (lateral and ventral view, respectively) K spermatheca (lateral view). Scale bars: 0.1 mm.