Simulium (Simulium) lardizabalae Takaoka & Sofian-Azirun

Takaoka, Hiroyuki, Sofian-Azirun, Mohd, Ya’Cob, Zubaidah, Chen, Chee Dhang, Lau, Koon Weng, Fernandez, Kevin & Lardizabal, Maria Lourdes, 2015, Revision of the Simulium (Simulium) melanopus species-group (Diptera: Simuliidae) in Sabah, Malaysia, Zootaxa 3985 (1), pp. 1-30 : 20-23

Simulium (Simulium) lardizabalae Takaoka & Sofian-Azirun sp. nov.

Male. Body length 3.3 mm. Head. Nearly as wide as or slightly wider than thorax. Upper eye consisting of large facets in 25 vertical columns and in 26 horizontal rows on each side. Clypeus brownish-black, whitish-pruinose, shiny and iridescent when illuminated at certain angles, moderately covered with dark-brown long hairs. Antenna composed of scape, pedicel and nine flagellomeres, brownish-black except scape dark brown; first flagellomere elongate, 1.9 times length of second one. Maxillary palp light brown except third segment dark brown, composed of five segments, proportional lengths of third, fourth, and fifth segments 1.00:1.11:2.22; third segment ( Fig. 10 A) of normal size; sensory vesicle ( Fig. 10 A) small, globular or ellipsoidal, 0.22–0.27 times length of third segment, and with small opening. Thorax. Nearly as in male of S. (S.) laterale except white spots on shoulders of scutum rounded posteromedially ( Fig. 10 B). Legs. Color pattern almost similar to that of male of S. (S.) nigripilosum including all tibiae with iridescent sheen widely on outer or posterior surface. Fore basitarsus greatly dilated, 5.04 times as long as its greatest width. Hind basitarsus ( Fig. 10 C) greatly enlarged, gradually widened toward apical one-third, then roundly narrowed, 3.21 times as long as its greatest width, 1.04 and 1.09 times as wide as greatest widths of hind tibia and femur, respectively; calcipala ( Fig. 10 C) slightly longer than its basal width, and 0.24 times as wide as greatest width of basitarsus; pedisulcus well developed. Wing. Length 2.5 mm. Other features as in male of S. (S.) crassimanum . Halter and Abdomen. Nearly as in male of S. (S.) nigripilosum . Genitalia. Coxites, styles and ventral plate in ventral view as in Fig. 10 D. Coxite in ventrolateral view ( Fig. 10 E) nearly quadrate, 0.86 times as long as wide. Style in ventrolateral view ( Fig. 10 F) elongate, 1.67 times length of coxite, 2.58 times as long as its greatest width, sinuous, widened from base to basal one-fourth, narrowed to middle, slightly widened to apical onefourth, then slightly narrowed toward round apex, and with stout apical spine; style in medial view ( Fig. 10 G) flattened dorsoventrally, gradually narrowed toward apex, and without basal or subbasal protuberance. Ventral plate in ventral view ( Fig. 10 D) with body nearly rectangular having ventrally produced median process that is bare except parts of lateral and anterior surfaces covered with minute setae, and is furnished with several teeth in vertical row on each posterolateral margin; basal arms of moderate length, stout and divergent; ventral plate in lateral view ( Fig. 10 H) with body and its ventrally produced process with rounded ventral apex, with dentate posterior margin, and covered with minute setae anterolaterally; ventral plate in caudal view ( Fig. 10 I) with body and ventrally produced median process gradually tapered from base to apex, bare, with several teeth in vertical row on each lateral margin. Median sclerite in lateral view ( Fig. 10 H) moderately sclerotized, folded backward, and in caudal view ( Fig. 10 J) plate-like, widened from base toward basal one-third, then slightly narrowed and again slightly widened. Paramere ( Fig. 10 K) wide basally and with several parameral hooks apically. Aedeagal membrane ( Fig. 10 L) moderately covered with minute setae, without sclerotized dorsal plate. Ventral surface of tenth abdominal segment ( Fig. 10 M, N) without distinct hairs. Cercus ( Fig. 10 M, N) rounded laterally, with 14 or 15 distinct hairs.

Pupa. Body length (excluding gill filaments) 3.5 mm. Head. Integument light brown, except frons and antennal sheaths dark brown to brownish black, bare on frons but sparsely covered with round tubercles on face: frons with two unbranched medium-long trichomes ( Fig. 11 A) on each side; face with one unbranched mediumlong trichome and one bifid short trichome ( Fig. 11 B) on each side. Thorax. Integument dark brown except dorsal surface of posterior one-fourth and wing sheaths light brown, moderately covered with round tubercles or coneshaped smaller tubercles except dorsal surface of anterior one-third almost bare, and lateral surface near base of gill densely covered with round tubercles; thorax with two anterodorsal trichomes ( Fig. 11 C), one anterolateral trichome ( Fig. 11 D) (another trichome lost), one mediolateral trichome ( Fig. 11 E), and three ventrolateral trichomes ( Fig. 11 F) on each side; all unbranched and medium-long. Gill ( Fig. 11 G) with six slender thread-like filaments in pairs; all pairs short stalked; upper filament of dorsal pair longest (1.3 mm), two filaments of ventral pair shortest (0.8 mm), and other filaments subequal in length to one another (1.1–1.2 mm); relative thickness of filaments from dorsal to ventral when compared basally 1.0:0.7:0.7:0.7:0.6:0.6; all filaments light brown though upper filament of dorsal pair somewhat darker, gradually tapered toward apices; stalks of dorsal and ventral pairs at angle of 90 degrees when viewed laterally; cuticular surface with distinct annular ridges and furrows throughout their length, covered with minute tubercles of different sizes, relatively larger ones on ridges and smaller ones on inter-ridge spaces. Abdomen. Dorsally, segment 1 light brown, posterior surface of segment 9 yellowish, other segments unpigmented; segment 1 without tubercles and with one unbranched short hair-like seta ( Fig. 11 H) on each side; segment 2 with one unbranched short hair-like seta and five unbranched minute setae ( Fig. 11 I) on each side; segments 3 and 4 each with four unbranched hooked spines and one unbranched minute seta on each side; segments 5, 6 and 9 without spine-combs; segments 7 and 8 each with well-developed spine-combs in transverse row on each side; segments 7–9 each with comb-like groups of minute spines on each side; segment 9 without terminal hooks. Ventrally, all segments unpigmented; segment 4 with two unbranched minute setae on each side; segment 5 with pair of bifid hooks submedially and one unbranched minute seta on each side; segments 6 and 7 each with pair of bifid inner and unbranched or bifid outer hooks widely spaced and one unbranched minute seta on each side. Grapnel-like hooklets absent. Cocoon ( Fig. 11 J, K). Wall-pocket-shaped, thickly woven, ochreous, not extended ventrolaterally; individual threads invisible; 3.5 mm long by 1.4 mm wide.

Type material. HOLOTYPE: Male (together with its associated pupal exuviae and cocoon), reared from pupa collected from a small stream (width 0.5 m, depth 10 cm, water temperature 13.9˚C, shaded, altitude 2,134 m, 06˚02.679’ N/116˚34.921’ E), slow flowing in a natural forest, along the trekking route to the peak of Mt. Kinabalu from Mesilau, 2–3 km from Mesilau, Mt. Kinabalu, Sabah, Malaysia, 24-VI-2014, by M. Sofian-Azirun, Z. Ya’cob, C.D. Chen, K.W. Lau, N.A. Jamil & M. Rasul.

Ecological notes. The pupa of this new species was collected from a slender stalk of a trailing grass in the water. The associated species were S. (N.) borneoense and S. (S.) aeneifacies .

Etymology. The species name lardizabalae is in honor of Dr. Maria Lourdes Lardizabal, Universiti Malaysia Sabah, for her kind and enthusiastic collaboration in the current surveys.

Remarks. The male and pupa of this new species are similar to those of S. (S.) nigripilosum in having a similar male leg color, a similar arrangement of the pupal gill filaments and cocoon, though it is distinguished from the latter species in the male by the number of upper-eye facets (25 vertical columns and 26 horizontal rows in this new species versus 17–19 vertical columns and 19–21 horizontal rows in S. (S.) nigripilosum ) and in the pupa by the bare frons and dorsal surface of the anterior one-third of the thorax.

Figures

FIGURE 10. Male of Simulium (Simulium) lardizabalae sp. nov. (A) Third segment of maxillary palp with sensory vesicle (right side; front view). (B) Scutum showing pruinose pattern (dorsal view). (C) Basitarsus and second tarsomere of hind leg (left side; outer view). (D) Coxites, styles and ventral plate (ventral view). (E) Coxite (right side; ventrolateral view). (F) and (G) Styles (right side; F, ventrolateral view; G, medial view). (H) Ventral plate and median sclerite (lateral view). (I) Ventral plate (caudal view). (J) Median sclerite (caudal view). (K) Paramere (right side; caudal view). (L) Aedeagal membrane (left half; caudal view). (M) and (N) Tenth abdominal segments and cerci (right side; M, lateral view; N, caudal view). Scale bars. 0.1 mm for C; 0.02 mm for A and D – N.

FIGURE 11. Pupa of Simulium (Simulium) lardizabalae sp. nov. (A) Frontal trichomes. (B) Facial trichomes. (C) – (F) Thoracic trichomes (C, anterodorsal; D, anterolateral; E, mediolateral; F, ventrolateral). (G) Anterior half of thorax and gill filaments (left side; outer view). (H) Slender short seta on dorsal surface of abdominal segment 1. (I) Slender short seta and minute seta on dorsal surface of abdominal segment 2. (J) and (K) Cocoons (J, dorsal view; K, lateral view). Scale bars. 1.0 mm for J and K; 0.1 mm for G; 0.02 mm for A – F, H and I.