Limbodessus cooperi Watts & Humphreys 2006

Limbodessus cooperi Watts & Humphreys, 2006

(Figs 67–68)

Source of material. One specimen of instar III was used for the description (Table 1). The larva was collected in association with adults at the following locality: Australia, Carey palaeovalley, Mt Morgan calcrete, Mt Weld Station, PB 5, BES 10584, 28.73174S, 122.15704E, 30–IX–2004, coll. W. F. Humphreys and S. J. B. Cooper.

Diagnosis (instar III). Larger species (HL more than 1.25 mm); head (Fig. 67) 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 moderately reduced (HW/ OCW 1.95–2.50); occipital suture present; lateral margins of parietal straight; secondary spiniform setae on lateral margins of parietal numerous; seta AN2 present; distal half of MN broad; setae LA3, LA4, LA5 and LA8 hair-like; secondary setae on U present (Fig. 68).

Instar I. Not available.

Instar II. Not available.

Instar III (Figs 67–68). Head (Fig. 67). 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 more than 1.75 times longer than labial palpus; MP2 3.20–4.00 times longer than MP3; LP2 more than 0.65 times as long as LP1. Legs. L3 less than 2.20 times longer than HW. Abdomen (Fig. 68). U 2.40–3.10 times longer than LAS; U less than 1.35 times longer than HW; U1 0.70–1.40 times as long as U2. Chaetotaxy. Anteroventral margin of nasale with 95 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 more than 12 anteroventral secondary setae; posterodorsal secondary setae on meso- and metaFE absent; metaFE with more than 30 secondary setae; metaTI with less than 9 anteroventral secondary setae; metaTI with more than 18 secondary setae; anterodorsal and present. Measurements and ratios that characterize the body shape are shown in Table 8. Secondary leg setation detailed in Table 16.

Remarks. The description of L. cooperi provided in this paper is based on a single specimen, which has the fourth antennomere broken and both the pro- and mesothoracic legs broken at the level of femur. For this reason, some morphometric and chaetotaxic characters could not be evaluated. This species is included in the group of stygobitic species characterized by the presence of secondary setae on the urogomphus (L. barwidgeeensis, L. bigbellensis, L. eberhardi, L. macrohinkleri, L. nambiensis, L. raesideensis, L. yandalensis) (Fig. 68). Within the group, L. cooperi is distinguished by the following combination of characters: head subpentagonal (Fig. 67), occipital suture present (Fig. 67), occipital foramen moderately reduced (Fig. 67), absence of anterior secondary setae on the procoxa, absence of posterodorsal secondary setae on the meso- and metafemur, and presence of anterodorsal secondary setae on the metatarsus. The nasale in L. cooperi is more triangular than in other presumably closely related species.