Limbodessus hillviewensis (Watts & Humphreys, 2004)

Michat, Mariano C., Alarie, Yves & Watts, Chris H. S., 2012, 3584, Zootaxa 3584 (1), pp. 1-110 : 44

Limbodessus hillviewensis (Watts & Humphreys, 2004)

(Figs 81–84)

Source of material. One specimen of instar III was used for the description ( Table 1). Larva was collected in association with adults at the following locality: Australia, Murchison palaeovalley, Hillview calcrete, bore at Camel Well, BES 9399, 26.97222S, 117.4525E, 13–VI–2002, coll. W. F. Humphreys and R. Leys.

Diagnosis (instar III). Medium-sized species (HL 0.55–1.15 mm); head (Fig. 81) subpentagonal; nasale subtriangular; half-circle of dense spinulae on lateroventral margins of nasale absent; hole-like structure on ventrodistal surface of nasale absent; lateral margins of nasale not inflated in dorsal view; lateral branches of nasale minute; slender spinulae anterior to seta FR13 scarce (20 or less); occipital foramen well developed (HW/OCW less than 1.90); occipital suture present; lateral margins of parietal straight; secondary spiniform setae on lateral margins of parietal scarce; seta AN2 present; distal half of MN broad; setae LA3, LA4, LA5 and LA8 hair-like; secondary setae on U absent (Fig. 84).

Instar I. Not available.

Instar II. Not available.

Instar III (Figs 81–84). Head (Fig. 81). A3 less than 2.25 times longer than A1; A3 less than 1.45 times longer than A2; MN less than 4.85 times longer than broad; MP less than 1.75 times longer than labial palpus; MP2 2.10– 3.10 times longer than MP3; LP2 more than 0.65 times as long as LP1. Legs (Figs 82–83). L3 2.25–2.85 times longer than HW. Abdomen (Fig. 84). Chaetotaxy. Anteroventral margin of nasale with 50 lamellae clypeales distributed in 2 rows; pro- and mesoCO without anterior secondary setae; pro-, meso- and metaCO without posterior secondary setae; proCO with less than 11 secondary setae; metaCO with less than 20 secondary setae; anterodorsal secondary setae on pro- and metaFE present; metaFE with less than 12 anteroventral secondary setae; posterodorsal secondary setae on meso- and metaFE absent; metaFE with 9–27 secondary setae; anterodorsal secondary setae on proTI present; anteroventral and posterodorsal secondary setae on proTI absent; mesoTI with less than 4 anteroventral secondary setae; metaTI with less than 9 anteroventral secondary setae; metaTI with less than 16 secondary setae; secondary setae on proTA absent; anterodorsal and posteroventral secondary setae on meso- and metaTA absent; anteroventral and posterodorsal secondary setae on meso- and metaTA present; mesoTA with less than 7 secondary setae; metaTA with less than 16 secondary setae; secondary setae on U absent. Measurements and ratios that characterize the body shape are shown in Table 9. Secondary leg setation detailed in Table 17.

Remarks. This species was described on the basis of a single instar III which has the second urogomphomere broken. Limbodessus hillviewensis belongs to the group of stygobitic species characterized by the absence of secondary setae on the urogomphus ( L. challaensis , L. exilis , L. fridaywellensis , L. hinkleri , L. leysi , L. masonensis , L. millbilliensis , L. morgani , L. ordinarius , L. pulpa , L. raeae , L. windarraensis , L. yuinmeryensis ) (Fig. 84). Compared to other members of this group the larvae of L. hillviewensis are distinguished by having the lateral margins of the nasale not inflated in dorsal view (Fig. 81), the claws relatively shorter as compared to tarsus (ratio CL/TA <0.40), by the presence of anterodorsal secondary setae on the protibia (Fig. 82), the absence of anteroventral secondary setae on the protibia (Fig. 82), and the absence of posteroventral secondary setae on the