Limbodessus raesideensis (Watts & Humphreys, 2001)

Michat, Mariano C., Alarie, Yves & Watts, Chris H. S., 2012, 3584, Zootaxa 3584 (1), pp. 1-110 : 80-83

Limbodessus raesideensis (Watts & Humphreys, 2001)

( Figs 212–215 )

Source of material. Two specimens of instar II and two of instar III were used for the description ( Table 1). Larvae were collected in association with adults at the following localities: Australia, Raeside palaeovalley, Lake Mason calcrete, Salt Well, BES 8353, 27.54S, 119.62417E, 24–VI–2000, coll. W. F. Humphreys and S. Hinze ; Lake Mason calcrete, Salt Well, BES 14361, 27.586S, 119.5218E, 20–IX–2006, coll. W. F. Humphreys and T. Moulds.

Diagnosis (instar III). Larger species (HL more than 1.25 mm); head ( Fig. 212 ) 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 numerous (25 or more); occipital foramen strongly reduced (HW/OCW

Instar I. Not available.

Instar II. Head. A3 less 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 less than 1.05 times longer than MP1; MP2 more than 3.20 times longer than MP3; LP2 less than 0.90 times as long as LP1. Legs. L3 2.25–2.95 times longer than HW; CL(L3) less than 0.40 times as long as TA. Abdomen. U 3.00–4.00 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 70 lamellae clypeales distributed in 1–2 rows; anterior secondary setae on proCO absent; 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 proTI absent; anteroventral, posterodorsal and posteroventral secondary setae on proTI present; anterodorsal and posteroventral secondary setae on meso- and metaTI present; meso- and metaTI with less than 2 posterodorsal secondary setae; 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 7. Secondary leg setation detailed in Table 15.

Instar III ( Figs 212–215 ). Head ( Fig. 212 ). 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 ( Figs 213–214 ). L3 2.25–2.85 times longer than HW. Abdomen ( Fig. 215 ). U more than 3.10 times longer than LAS; U 1.55–2.25 times longer than HW; U1 1.80–2.60 times longer than U2. Chaetotaxy. Anteroventral margin of nasale with 134 lamellae clypeales distributed in 2 rows; proCO with more than 7 anterior secondary setae; mesoCO with 1–5 anterior secondary setae; pro-, meso- and metaCO without posterior secondary setae; proCO with more than 21 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 present; metaFE with more than 30 secondary setae; anterodorsal secondary setae on proTI absent; anteroventral and posterodorsal secondary setae on proTI present; mesoTI with more than 4 anteroventral secondary setae; metaTI with less than 9 anteroventral secondary setae; metaTI with more than 18 secondary setae; anterodorsal secondary setae on proTA absent; anterodorsal secondary setae on meso- and metaTA present; anteroventral and posterodorsal secondary setae on pro-, meso- and metaTA present; posteroventral secondary setae on pro- and mesoTA present; metaTA with 1–5 posteroventral secondary setae; proTA with 1–7 secondary setae; mesoTA with more than 7 secondary setae; metaTA with less than 16 secondary setae; secondary setae on U present. Measurements and ratios that characterize the body shape are shown in Table 11. Secondary leg setation detailed in Table 19.

Remarks. Limbodessus raesideensis is a very characteristic stygobitic species that belongs to the group of species characterized by the presence of secondary setae on the urogomphus ( L. barwidgeeensis , L. bigbellensis , L. cooperi , L. eberhardi , L. macrohinkleri , L. nambiensis , L. yandalensis ) ( Fig. 215 ). Within this group, it can be distinguished by the following combination of characters: head pyriform ( Fig. 212 ), occipital suture present ( Fig. 212 ), occipital foramen strongly reduced ( Fig. 212 ), presence of anterior secondary setae on the coxa ( Fig. 213 ), presence of posterodorsal secondary setae on the meso- and metafemur, femur with more than 30 secondary setae, and absence of anterodorsal secondary setae on the protibia and protarsus ( Fig. 213 ).

Figures

FIGURES 212–215. Limbodessus raesideensis, third-instar larva. 212, head, dorsal aspect; 213, left prothoracic leg, anterior