Pygatyphella russellia Ballantyne & Lambkin 2009, sp. n.

Pygatyphella russellia sp. n.

(Figs 405–416)

Holotype. Male. SOLOMON ISLANDS: Central Pr., Russell Island: Pavuvul Is, Pepesala, 0–100 m, 19.vii.1964, RS (BPBM).

Paratype (1). SOLOMON ISLANDS: Central Pr., Russell Island, R Lever (NHML); carries identification label as possible new species (Fig. 411).

Diagnosis. The only species in the Pygatyphella Group B complex with pale dorsal colouration.

Male. 8.8–9.2 mm long; 3.8–4.0 mm wide; W/L 0.4. Colour (Figs 405–407): Pronotum very pale light brownish yellow, semitransparent with underlying fat body visible, 2 barely defined small median brown areas; elytra yellowish brown, semitransparent, basal 1/3 very slightly darker than rest; head, antennae and palpi very dark brown; venter of thorax pale yellowish brown except for brown tarsi; V1, 2 yellowish, V3 with small midlateral brown markings, V4 mostly dark brown with lateral areas narrowly pale; V5 very dark brown with 4 very small yellow spots along anterior margin; LO in V6, 7 creamy white, posterior area of V7 yellowish; basal tergites yellowish, T4–6 marked irregularly in light brown, extent of markings increases from 4–6; T7 and 8 orange yellow and semitransparent. Pronotum (Fig. 407): 2.0– 2.2 mm long; 3.4–3.5 mm wide; W/L 1.6; lateral margins with rounded convergence in posterior areas; lacking indentation near posterolateral corners; with slight irregularities along posterolateral corners, corners rounded and projecting beyond median posterior margin. Elytron: parallel-sided; 7.0 mm long; interstitial lines not well–defined. Head: moderately exposed, not able to be completely retracted into prothoracic cavity; GHW 2.0– 2.3 mm; SIW 0.2 mm; SIW/ GHW 0.1; ASD<ASW, sockets very close not contiguous; frons not defined. Abdomen, ventrites (Figs 408–410): V6 very short (probably post–mortem effect as it seems to be retracted anteriorly beneath V5); LO in V7 occupying less than half V7, not reaching sides, posterior margin not emarginated; muscle impressions clearly visible through cuticle in posterior half which is arched not swollen; posterolateral corners of V7 angulate. MPP symmetrical, elongate, subparallel-sided, posterior margin very slightly obliquely truncate (scored as rounded), with broad dorsal ridge slightly to left of centre. Tergites: T8 (Fig. 410) as wide as long, with low rounded barely curved elevation in posterior area to one side of mid-line; lateral margins converge posteriorly and median posterior margin (from above) narrowly rounded; anterolateral prolongations of T8 elongate, narrow, anterior ends narrowly rounded, expanded vertically; ventrally directed pieces on prolongations of T8 appear to be present at base of prolongation. Aedeagal sheath (Figs 414, 415) subparallel-sided for half its length past articulation with sheath tergite, with right side emarginate; left lateral margin of anterior arms of tergite slightly produced; anterior margin of tergite not emarginate. Aedeagus (Figs 412, 413, 416): L/W 2.25; LL/ML wide; LL diverge along most of length dorsally, are slightly shorter than ML, with apices rounded and subequal in width to ML; ML bearing narrow pointed lateral teeth, apex rounded truncate; base of LL not asymmetrically produced, slightly irregularly rounded.

Female, Larva. Unknown.

Etymology. The specific name is a noun in apposition formed from the type locality. Olivier recognised the distinctiveness of the NHML specimen (Fig. 411).