Limbodessus macrohinkleri Watts &amp; Humphreys 2006
Creators: name: Michat, Mariano C.
name: Alarie, Yves
name: Watts, Chris H. S.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Dytiscidae
Limbodessus
Limbodessus macrohinkleri

description: <i>Limbodessus macrohinkleri</i> Watts &amp; Humphreys, 2006 (Figs 107–110) <b>Source of material.</b> One specimen of instar II was used for the description (Table 1). The larva was collected in association with adults at the following locality: <b>Australia, Carey palaeovalley</b>, Hinkler Well calcrete, Lake Way Station, Dawson’s Well, BES 10493, 26.88651S, 120.16203E, 3–VI–2004, coll. W. F. Humphreys, C. H. S. Watts and C. Clay. <b>Diagnosis (instar II).</b> Larger species (HL more than 1.05 mm); head (Fig. 107) pyriform; nasale digitiform; 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 well developed; slender spinulae anterior to seta FR13 scarce (20 or less); occipital foramen strongly reduced (HW/OCW more than 2.70); occipital suture absent; lateral margins of parietal curved; 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. 110). <b>Instar I.</b> Not available. <b>Instar II</b> (Figs 107–110). Head (Fig. 107). A3 more than 2.50 times longer than A1; A4 less than 0.70 times as long as A3; MN less than 4.70 times longer than broad; MP2 1.05–1.45 times longer than MP1; MP2 more than 3.20 times longer than MP3; LP2 less than 0.90 times as long as LP1. Legs (Figs 108–109). L3 2.25–2.95 times longer than HW; CL(L3) less than 0.40 times as long as TA. Abdomen (Fig. 110). U more than 4.15 times longer than LAS; U less than 2.15 times longer than HW; U1 more than 1.65 times longer than U2. Chaetotaxy. Anteroventral margin of nasale with 228 lamellae clypeales distributed in 3–4 rows; anterior secondary setae on proCO present; meso- and metaCO with less than 5 posterodorsal secondary setae; ventral secondary setae on pro- and mesoCO present; proFE with more than 3 posteroventral secondary setae; metaFE with more than 11 secondary setae; anterodorsal secondary setae on pro-, meso- and metaTI absent; anteroventral and posterodorsal secondary setae on proTI present; mesoTI with more than 3 posterodorsal secondary setae; metaTI with more than 2 posterodorsal secondary setae; posteroventral secondary setae on pro-, meso- and metaTI present; metaTI with more than 5 secondary setae; anterodorsal secondary setae on proTA absent; anteroventral and posteroventral secondary setae on proTA present; posterodorsal and posteroventral secondary setae on meso- and metaTA present; metaTA with more than 5 secondary setae; secondary setae on U present. Measurements and ratios that characterize the body shape are shown in Table 5. Secondary leg setation detailed in Table 13. <b>Instar III.</b> Not available. <b>Remarks.</b> The absence of instar III specimens of <i>L. macrohinkleri</i> hampers the comparison with the other species described here, particularly regarding some chaetotaxic characters. <i>Limbodessus macrohinkleri</i> belongs to the group of stygobitic species characterized by the presence of secondary setae on the urogomphus (<i>L. barwidgeeensis</i>, <i>L. bigbellensis</i>, <i>L. cooperi</i>, <i>L. eberhardi</i>, <i>L. nambiensis</i>, <i>L. raesideensis</i>, <i>L. yandalensis</i>) (Fig. 110), and within this group it can be distinguished by the following combination of characters: head pyriform (Fig. 107), occipital suture absent (Fig. 107), occipital foramen strongly reduced (Fig. 107), and absence of anterodorsal secondary setae on the protibia (Fig. 108).
description: Published as part of <i>Michat, Mariano C., Alarie, Yves &amp; Watts, Chris H. S., 2012, 3584, pp. 1-110 in Zootaxa 3584 (1)</i> on pages 54-56, DOI: 10.11646/zootaxa.3584.1.1
description: {"references": ["Watts, C. H. S. &amp; Humphreys, W. F. (2006) Twenty-six new Dytiscidae (Coleoptera) of the genera Limbodessus Guignot and Nirripirti Watts &amp; Humphreys, from underground waters in Australia. Transactions of the Royal Society of South Australia, 130, 123 - 185."]}