Limbodessus barwidgeeensis Watts & Humphreys, 2006

Michat, Mariano C., Alarie, Yves & Watts, Chris H. S., 2012, 3584, Zootaxa 3584 (1), pp. 1-110 : 24-27

Limbodessus barwidgeeensis Watts & Humphreys, 2006

( Figs 27–30 )

Source of material. One specimen of instar II was used for the description ( Table 1). Larva was collected in association with adults at the following locality: Australia, Carey palaeovalley, Barwidgee calcrete, site 144, BES

Diagnosis (instar II). Larger species (HL more than 1.05 mm); head ( Fig. 27 ) 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; parietal numerous; seta AN2 present; distal half of MN broad; setae LA3, LA4, LA5 and LA8 robust; secondary setae on U present ( Fig. 30 ).

Instar I. Not available.

Instar II ( Figs 27–30 ). Head ( Fig. 27 ). 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 ( Figs 28–29 ). L3 2.25–2.95 times longer than HW; CL(L3) less than 0.40 times as long as TA. Abdomen ( Fig. 30 ). Chaetotaxy. Anteroventral margin of nasale with 132 lamellae clypeales distributed in 2–3 rows; anterior secondary setae on proCO absent; meso- and metaCO with more than 5 posterodorsal secondary setae; ventral secondary setae on mesoCO present; proFE with more than 3 posteroventral secondary setae; metaFE with more than 11 secondary setae; anterodorsal secondary setae on proTI absent; anterodorsal secondary setae on meso- and metaTI present; anteroventral and posterodorsal secondary setae on proTI present; mesoTI with less than 2 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 and anteroventral secondary setae on proTA absent; posterodorsal secondary setae on meso- and metaTA present; posteroventral secondary setae on pro-, 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.

Instar III. Not available.

Remarks. The description of L. barwidgeeensis is based on a single instar II specimen which has the procoxa and the second urogomphomere broken. For this reason, some morphometric and chaetotaxic characters could not be evaluated. The absence of instar III specimens of this species hampers the comparison with the other species described here, particularly regarding some chaetotaxic characters. Limbodessus barwidgeeensis belongs to the group of stygobitic species characterized by the presence of secondary setae on the urogomphus ( L. bigbellensis , L. cooperi , L. eberhardi , L. macrohinkleri , L. nambiensis , L. raesideensis , L. yandalensis ) ( Fig. 30 ), and within this group it can be separated by the following combination of characters: head pyriform ( Fig. 27 ), occipital suture present ( Fig. 27 ), occipital foramen moderately reduced ( Fig. 27 ), and labial setae LA3, LA4, LA5 and LA8 more robust.

Figures

FIGURES 27–30. Limbodessus barwidgeeensis, second-instar larva. 27, head, dorsal aspect; 28, left prothoracic leg, anterior aspect; 29, right prothoracic leg, posterior aspect; 30, abdominal segment VIII and urogomphi, dorsal aspect. Scale bars = 0.15 mm.