Dichaetophora trilobita 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 : 124

Dichaetophora trilobita Yang & Gao sp. n.

Figs 3A-D , 4A-E , 5

Type material.

Holotype ♂ (#03877): MALAYSIA: Ulu Gombak, Selangor, 8.xii.2013, MJ Toda (UMKL).

Paratypes: same data as holotype (1♀: #03878, UMKL); Kubah, Sarawak, Malaysia, 19.i.1999 (1♂, 1♀, SEHU); Park Headquarters, Mt. Kinabalu, Sabah, Malaysia, 11.iii.2008, MJ Toda (1♂: #03876, KIZ); Poring, Mt. Kinabalu, Sabah, Malaysia, 20.iii.2008, MJ Toda (1♀: #03882, KIZ).

Diagnosis.

Postocellar setae absent; wing without distinct cloud (Fig. 3C ); sclerotized, caudoventral bridge of cerci with small, narrow, apically pointed, median process and a pair of lateral, broad, apically rounded lobes (Fig. 5A ); aedeagus apically curved, hook-like, and finely wrinkled all over, subapically with numerous, coarse serrations, submedially not swollen dorsally (Fig. 5G ); spermatheca without distinct introvert (Fig. 5K ).

Description.

Head (Figs 3A, B , 4A-E ): First flagellomere grayish yellow. Dorsolateral tentorial apodemes slightly divergent in basal 2/5 but strongly divergent in distal 3/5; supracervical setae 21-23 per side; postocular setae 22-23 per side. Palpus with two subprominent, lateromedial setae. Cibarium with ca. 70 medial and ca. 8 posterior sensilla per side.

Wings (Fig. 3C ): Veins pale brown to brown. Halter pale gray; stem darker.

Legs (Fig. 3A ) pale grayish yellow; mid- and hindleg femora distally, foreleg tibia and tarsi proximally to medially darker. Apical setae present on all tibiae; hindleg apical seta short, stout. Mid-leg first tarsomere longer than total length of four succeeding tarsomeres; hindleg first tarsomere as long as total length of four succeeding tarsomeres.

Male terminalia (Fig. 5A-H ): Epandrium pubescent except for anterior to ventral margin, with 1-3 dorsal and ca. 22 ventral, long setae per side. Surstylus with peg-like prensisetae in sinuate row on caudal margin, 2-5 apically pointed spines and medial patch of pubescence on outer surface and ca. 26 apically pointed spines (ventral ones shorter, thicker and straight, but medial to dorsal ones trichoid and recurved) on inner, caudal portion. Tenth sternite nearly flat. Cercus pubescent except for caudal margin, with 11-12 long setae near dorsal to posterior margin and 7-11 short setae in cluster on ventral portion of sclerotized marginal plate. Paramere with sensilla apically.

Female terminalia (Fig. 5I-K ): Oviscapt valve dorsomedially narrowly extended, with 3-4 lateral and 9-13 marginal, peg-like ovisensilla.

Measurements (in mm): BL (straight distance from anterior edge of pedicel to tip of abdomen) = 2.03 in holotype (1♂ paratype: 2.00; range in 2♀ paratypes: 2.00-2.21), ThL (distance from anterior notal margin to apex of scutellum) = 0.84 (0.82; 0.86-0.88), WL (distance from humeral cross vein to wing apex) = 1.62 (1.69; 1.72-1.73), WW (maximum wing width) = 0.71 (0.72; 0.74-0.79).

Indices: FW/HW (frontal width/head width) = 0.53 (range in 1♂, 2♀, or less if noted, paratypes: 0.38-0.50), ch/o (maximum width of gena/maximum diameter of eye) = 0.18 (0.19-0.26), prorb (proclinate orbital seta/posterior reclinate orbital seta in length) = 0.72 (2♀: 0.71-0.80), rcorb (anterior reclinate orbital seta/posterior reclinate orbital seta in length) = 0.30 (2♀: 0.31-0.33), orbito (distance between proclinate and posterior reclinate orbital setae / distance between inner vertical and posterior reclinate orbital setae) = 0.60 (0.58-0.68), dcl (anterior dorsocentral seta/posterior dorsocentral seta in length) = 0.78 (2♀: 0.64-0.74), sctl (basal scutellar seta/apical scutellar seta in length) = 0.67 (1♀: 0.60), sterno (anterior katepisternal seta/posterior katepisternal seta in length) = 0.51 (0.57-0.60), dcp (distance between ipsilateral dorsocentral setae/distance between anterior dorsocentral setae) = 0.49 (0.53-0.60), sctlp (distance between ipsilateral scutellar setae/distance between apical scutellar setae) = 0.79 (0.68-0.77), C (2nd costal section between subcostal break and R2+3/3rd costal section between R2+3 and R4+5) = 1.57 (1.35-1.53), 4c (3rd costal section between R2+3 and R4+5/M1 between r-m and dm-cu) = 1.54 (1.46-1.66), 4v (M1 between dm-cu and wing margin/M1 between r-m and dm-cu) = 2.19 (2.11-2.33), 5x (CuA1 between dm-cu and wing margin/dm-cu between M1 and CuA1) = 2.19 (2.00-2.38), ac (3rd costal section between R2+3 and R4+5/distance between distal ends of R4+5 and M1) = 3.58 (3.66-3.76), M (CuA1 between dm-cu and wing margin/M1 between r-m and dm-cu) = 0.72 (0.66-0.70), C3F (length of heavy setation in 3rd costal section/length of 3rd costal section) = 0.70 (0.66-0.68).

Etymology.

Referring to the trilobed, caudoventral bridge of cercal sclerotized plates.

Distribution.

Malaysia (Peninsular Malaysia, Sarawak, Sabah).

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 5. Dichaetophora trilobita sp. n. (A-H # 03877 I-K paratype # 03878). A Periphallic organs (posterior view), with red arrow indicating the median process on the caudoventral bridge of cerci B periphallic organs (posterolateral view), with red arrows indicating the prominent setae on the cercus and the anteroventral fusion of cercus (sclerotized, marginal plate) with the epandrium C surstyli (ventral view) D surstylus (inner side) E-G phallic organs (ventral, ventrolateral and lateral view, respectively) H paramedian setae (indicated with red arrows), and apical portion of paramere I, J oviscapt (lateral and ventral view, respectively) K spermathecae. Abbreviations: aed = aedeagus, aed a = aedeagal apodeme, cerc = cercus, epand = epandrium, hypd = hypandrium, pm = paramere, sur = surstylus, 10 S = tenth sternite. Scale bars: 0.1 mm.