Simulium (Hebridosimulium) anatolicum Craig, 1987

Craig, Douglas A., Currie, Douglas C., Hunter, Fiona F. & Spironello, Mike, 2006, A taxonomic revision of the southwestern Pacific subgenus Hebridosimulium (Diptera: Simuliidae: Simulium), Zootaxa 1380 (1), pp. 1-90 : 49-50

Simulium (Hebridosimulium) anatolicum Craig

( Figs. 5e , 8e , 9f ).

S. (Hebridosimulium) anatolicum Craig 1987: 382 . Crosskey & Howard (2004: 29)

Type

Holotype. Female: pinned; reared, with pupal cocoon and exuviae as subsidiary material. Label data – " Holotype, Simulium (H.) anatolicum Craig , det. D.A. Craig 1986, Tahiti, Mahaena, Mahape R., 17° 34' 00" S. 149° 20' 33" W. alt. 700m. 14.vi.1980, D.A. & R.E.G. Craig. Stat. #6." ( MNHP). Head, genitalia and pupal exuviae in vial on pin. Left gill of pupa as slide mount, same data as adult ( MNHP).

Diagnosis

Large species. Adult female: yellowish; mandibles small; veins R 1 and Sc lacking hair; hypogynial valves with apical membranous region not extended. Pupa: sternite V hooks, close-set. Cocoon: anteroventral edge with small fenestrae.

Redescription

Adult female (Holotype). Body: generally yellowish-brown, total length 2.5 mm. Head: grayish-brown, width 0.98 mm, depth 0.69 mm; frons bulging ventrally over sunken antennal bases, densely covered with silver scale-like hairs, frons-head ratio 1:6.1. Eyes: interocular distance 0.16 mm; yellowish-gray; frontal angle, 115 degrees; ommatidia 0.014 mm in diameter, ca. 34 and 45, respectively, across and down at mid-eye. Clypeus: 0.22 mm wide; concolourous with ventral region of frons, slightly longer than wide, densely covered with silver hairs medially; lateral hairs dark, extended beyond bases of maxillary palpus. Postocciput: densely covered with silver hairs extended to eye margin, scattered long black hairs extended over posterior margin of eye. Antenna: length 0.63 mm; flagellomeres and basal articles yellowish. Mouthparts: 0.5 length of head depth; mandibles with ca. 30 very fine teeth; lacinia with ca. 25 pronounced teeth; maxillary palpus (distal articles absent from specimen) with basal articles flattened and densely covered with black hairs; sensory vesicle of third article elongated, occupying 0.5 width of article, opening of vesicle 0.66 width of vesicle. Thorax: rich brown; length 1.4 mm, width 1.1 mm; postpronotum and contiguous area of scutum creamy, remainder of scutum uniformly brown, moderate vestiture of silver hair, in some views 3 darker vittae; scutellum yellowish, with sparse black and golden hairs; postnotum brown medially and posteriorly, yellow laterally; pleural membrane with distinct pale yellow flattened hairs, as for S. laciniatum (e.g., Fig. 4b ). Wing: length 2.9 mm, maximum width 1.3 mm; veins pale yellow, hairs black. Legs: coxae, femora, and tibiae yellow, distal portion of tibiae brown; fore basitarsus 6 times longer than wide, brown anteriorly; hind basitarsus parallel sided, 7 times longer than wide; calcipala enormously extended to 0.66 times length of 2nd tarsomere. Abdomen: overall black with dense dark scales anteriorly, pale scales posteriorly on each segment; basal fringe of shiny dark golden hairs extended to 2nd abdominal segment; tergites III–VII lighter in colour than others; sternite VII distinct, narrower anteriorly; pleural regions with dense silver scales. Genitalia ( Fig. 5e ): sternite VIII not deeply indented, broader anteriorly, dark brown; hypogynial valves lightly pigmented, sparse vestiture, medial edges slightly concave, not divergent, rounded apically, membranous, but not extended; genital fork with stem narrow, posterolateral arms pigmented, with anteriorly directed apodeme on lateral arm large and cone-shaped; anal lobe rounded with marked anterolateral apodeme, median depression not developed; cercus ovoid; spermatheca (destroyed during preparation for illustration): dark brown (probably reticulated).

Adult male: Unknown.

Pupa (based on exuviae). Body length. 3.6 mm. Gill ( Fig. 9f ): 8 filaments, maximum length 1.4 mm, petioles moderately elongate, branching pattern (2+1)+2+2+1, dorsal filaments subequal in length, markedly shorter than ventral filaments, evenly tapered, annulations fine. Thorax: dorsal cuticle with dense rounded granules ( Fig. 8e ), those more lateral and posterior, pointed and hooked. Cocoon: shoe shaped, 4.6 mm long, 1.6 mm wide, basal edges not flared, anteroventral edge rough, with small fenestrae.

Distribution POLYNESIA. Tahiti.

Comments

The pupa from which the adult was reared came from grass trailing in a small, rapidly flowing, open stream. Velocity was ca. 80cm /s and temperature 29 ° C. Larvae of Simulium tahitiense and S. lotii were taken from the same locality ( Craig 1987).

This single specimen from a subgenus unexpected in Tahiti, was initially thought by Craig (1987) to be a contaminant from collections made either in Fiji or Vanuatu. However, Simulium anatolicum , while very similar to S. jolyi and S. laciniatum , shows differences in the wings and genitalia and is considered here a valid species. The pupa of S. anatolicum has eight filaments, indicating that it is more closely related to the Fijian S. laciniatum . No new material has ever been found in Tahiti despite extensive searching ( Craig et al. 2001), so S. anatolicum remains enigmatic.

Figures

FIGURE 4. Hebridosimulium. Female adult right pleural membranes. Dorsal to the left, anterior up. Scale bar = 0.1 mm.

FIGURE 5. Hebridosimulium. Female genitalia. a–d callipygium species group, e–j steatopygium species group. e. Adapted from Craig (1987). Scale bar = 0.1 mm. Abbreviations: an lb — anal lobe; cerc — cercus; gen fk — genital fork; hyp vlv — hypogynial valve; spmth — spermatheca.

FIGURE 8. Hebridosimulium. Pupal thoracic cuticle. Scale bar = 0.1 mm.

FIGURE 9. Pupal gill filaments of Hebridosimulium species. Scale bar = 0.2 mm.