Limbodessus amabilis (Clark, 1862)

Michat, Mariano C., Alarie, Yves & Watts, Chris H. S., 2012, 3584, Zootaxa 3584 (1), pp. 1-110 : 14-17

Limbodessus amabilis (Clark, 1862)

( Figs 1 –11)

Source of material. Three 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: South Australia, 1 km S Nangwarry, 5–X–2000 and 22–IX–2007, coll. C. H. S. Watts; 10 km N Forrestown, 1–IX–2002, coll. C. H. S .

Diagnosis (instar III). Medium-sized species (HL 0.55–1.15 mm); head (Fig. 8) 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 curved; secondary spiniform setae on lateral margins of parietal scarce; seta AN2 present ( Fig. 2 ); distal half of MN broad ( Fig. 5 ); setae LA3, LA4, LA5 and LA8 hair-like ( Fig. 6 ); secondary setae on U absent (Fig. 11).

Instar I. Not available.

Instar II ( Figs 1–7 ). Head. 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 2.10–2.95 times longer than MP3; LP2 1.00–1.70 times longer than LP1. Legs. L3 2.25–2.95 times longer than HW; CL(L3) more than 0.40 times as long as TA. Abdomen. U 3.00–4.00 times longer than LAS; U more than 2.25 times longer than HW; U1 less than 1.45 times longer than U2. Chaetotaxy. Anteroventral margin of nasale with 25 lamellae clypeales distributed in a single row; 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 less than 3 posteroventral secondary setae; metaFE with more than 11 secondary setae; anterodorsal secondary setae on pro-, meso- and metaTI present; anteroventral and posterodorsal secondary setae on proTI absent; meso- and metaTI with less 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 present; anteroventral secondary setae on proTA absent; posterodorsal secondary setae on meso- and metaTA absent; posteroventral secondary setae on pro-, meso- and metaTA present; metaTA with more than 5 secondary setae; secondary setae on U absent. Measurements and ratios that characterize the body shape are shown in Table 5. Secondary leg setation detailed in Table 13.

Instar III (Figs 8–11). Head (Fig. 8). 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 9–10). L3 2.25–2.85 times longer than HW. Abdomen (Fig. 11). Chaetotaxy. Anteroventral margin of nasale with 50 lamellae clypeales distributed in 2 rows; proCO with 1–4 anterior secondary setae; mesoCO with 1–5 anterior secondary setae; pro-, meso- and metaCO without posterior secondary setae; proCO with 12–15 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 and anteroventral secondary setae on proTI present; mesoTI with less than 4 anteroventral secondary setae; metaTI with less than 9 anteroventral secondary setae; posterodorsal secondary setae on proTI absent; metaTI with less than 16 secondary setae; anterodorsal secondary setae on pro-, meso- and metaTA present; anteroventral secondary setae on pro- and mesoTA absent; anteroventral secondary setae on metaTA present; posterodorsal secondary setae on pro-, meso- and metaTA absent; posteroventral secondary setae on pro- and mesoTA present; metaTA with 1–5 posteroventral secondary setae; proTA with 1–7 secondary setae; 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 8. Secondary leg setation detailed in Table 16.

Remarks. All the instar III specimens of L. amabilis examined had the second urogomphomere broken, which prevented the evaluation of urogomphal morphometry. This species belongs to the epigean Limbodessus characterized by the absence of secondary setae on the urogomphus ( L. compactus , L. shuckardii ) (Fig. 11). Within this group, L. amabilis can be distinguished by its larger size, the presence of anterodorsal secondary setae on the tarsus (Fig. 9), and the absence of posterodorsal secondary setae on the meso- and metatarsus. The larva of L. amabilis was previously described by Watts (1963) (as Liodessus amabilis ).

Figures

FIGURES 1–7. Limbodessus amabilis, second-instar larva. 1, right antenna, dorsal aspect; 2, left antenna, ventral aspect; 3,