Copelatus florae Hájek, Alarie, Benetti, et al., sp. nov.

(Figs 4B, 5)

Material studied: One larva of instar II, three larvae of instar III, same data as holotype (YALC, ZSMG); one larva of instar III, Brazil: Amazonas, Manaus, Reserva Ducke, collected together with adults (INPA).

Description of instar III: Body subcylindrical, narrowing towards abdominal apex (Fig. 4B). Measurements and ratios that characterize the body shape are shown in Table 1.

Colour: Body predominantly testaceous; head capsule yellow, pale yellow maculae posteriorly on frontoclypeus, laterally on parietale and over most of the occiput (Fig. 5A); head appendages, legs, and urogomphi pale yellow.

Head: Cephalic capsule (Fig. 5A) rounded, about as broad as long; dorsal surface covered with much impressed scale-like microsculptures; maximum width at about level of stemmata; neck constriction well marked; occipital suture present; ecdysial line well marked, coronal line short; occipital foramen broadly emarginate ventrally; frontoclypeus subtriangular, anterior margin rounded medially, with about 34–38 short spine-like spinulae [= lamellae clypeales of Bertrand (1972)]; slightly extending medially beyond level of lateral lobes [= adnasalia of Beutel (1994)]; lateral lobes almost indistinct, bluntly serrated along outer margin; gular suture visible; ocularium present, with six stemmata visible ventrally and subdivided into two vertical series; tentorial pits visible ventrally on each side of middle at about midlength. Antenna short, slender, shorter than HW, composed of four antennomeres; A4 shortest, A2 longest, A1 and A3 subequal in length; A3 with a ventroapical spinula; lateral elongation of antennomere 3 (A3’) finger-like, short. Mandible (Fig. 5A) prominent, falciform, longer than broad, distal half projected inwards, apex sharp; mandibular channel absent, internal margin with bluntly rounded denticles. Maxilla (Fig. 5B) with cardo well developed; stipes trapezoidal with minute surface spinulae and three robust spinulae along inner margin proximad to galea; galea strongly developed, spiniform; palpifer well developed, palpomere like; palpus short, 3-segmented, shorter than antenna; MP2 and MP3 subequal in length, longer than MP1. Labium (Fig. 5C) with prementum well developed, subrectangular, broader than long, dorsal surface with small rounded tuberculi bearing primary spiniform setae, lateral margin with elongate and spine-like spinulae; palpus short, 2-segmented, about half as long as maxillary palpus; LP2 subequal in length to LP1.

Thorax: Pronotum trapezoidal dorsally, ovate laterally, shorter than meso- and metanotum combined (Fig. 4B); meso- and metanotum subequal, with anterotransverse carina; sagittal line visible on the three tergites; thoracic terga densely tuberculate; meso- and metatergite tuberculi bearing a short hair-like seta; thoracic sterna membranous; spiracles present on mesothorax.

Legs (Fig. 5D–E) short, robust, composed of six articles (including pretarsus), L1 and L2 subequal in length, L3 the longest, slightly longer than L1 and L2; CO robust, elongate, TR divided into two parts by annulus, FE, TI and TA slender, subcylindrical; PT with two short and slightly curved claws, posterior claw shorter than anterior claw on L1 and L2, posterior claw longer than anterior one on L3; ventral margin of pro- and mesotibiae, and pro- and mesotarsi with elongate spine-like spinulae; marginal spinulae more faintly developed on metatibia and metatarsus; minute spine-like microsculptures broadly developed over posterior surface of tibiae and tarsi and, to a lesser extent, along the dorsal margin of metacoxae and posteroventral margin of femora.

Abdomen (Figs 4B, 5F–G) eight-segmented; segments I–VI sclerotized dorsally, membranous ventrally, segments VII and VIII (= LAS [last abdominal segment; i.e. abdominal segment VIII]) completely sclerotized; all tergites with an anterotransverse carina and densely tuberculate, tuberculi bearing a short spiniform seta; sagittal line visible on segments I–VII; spiracles present on segments I–VII; LAS the longest, subconical, extended posteriorly, lacking constriction at level of insertion of urogomphi, with a pair of spiracular openings extending apically, ventral surface much less sclerotized than dorsally and densely covered with spiniform setae. Urogomphus (Fig. 5F–G) one-segmented, very short.

Chaetotaxy: Similar to that of generalized Copelatinae larva (Alarie et al. 2022); cephalic capsule with numerous minute and hair-like secondary setae, 10–12 spine-like setae on lateral margin of parietale (Fig. 5A); mandible with several tiny secondary setae along external margin; stipes with two minute secondary setae on ventral surface; prementum with secondary pores on ventral surface; thoracic and abdominal tergites with numerous short either hair-like (thorax) or spine-like (abdomen) secondary setae inserted on the apices of rounded tuberculi; ventral surface of LAS with several spiniform secondary setae; secondary leg setation detailed in Figure 5D–E; coxae with three secondary pores on posterior surface; trochantera with one secondary pore on proximal portion; urogomphi lacking secondary setae (Fig. 5F–G).

Description of instar II: As instar III except for the following features:

Body: Measurements and ratios that characterize the body shape are shown in Table 1.

Head: Apical margin of frontoclypeus with 28 lamellae clypeales. Antenna with A2 and A3 longest, subequal in length; A1 shorter than A3. Maxilla with MP3 longer than MP2. Labium with LP2 distinctly longer than LP1.

l, length.w, width.

Chaetotaxy: Cephalic capsule with seven spiniform secondary setae along the lateral margin of parietale; secondary leg setation detailed in Table 2.

Comments: Until very recently, our knowledge of the larval morphology of the Copelatinae was scanty, while the larvae of a limited number of species were most often described very superficially (Williams 1936, Spangler 1962, Watts 1963, Bertrand 1972, De Marzo 1976, Mashke et al. 2001, Michat and Torres 2009, Watanabe et al. 2017, Watanabe and Hayashi 2019). All of these species and several others have recently been described in a detailed study of Copelatinae larval morphology including a provisional phylogenetic analysis (Alarie et al. 2022). This theoretical platform represents a useful tool for comparing the morphological particularities of C. florae.

Larvae of C. florae share with all previously described Copelatinae species: (1) the presence of two rows of denticles albeit in a much more reduced form along the internal margin of the mandible (Fig. 5A); (2) the anterior margin of anterolateral lobes (= adanasalia) of frontoclypeus dentate (Fig. 5A); (3) the absence of a mandibular channel; (4) the presence of three robust spinulae along the internal margin of the stipes (Fig. 5B); (5) the galea spiniform, much longer than maxillary palpomere I in instar III (Fig. 5B); (6) the lateral margin of prementum with strong spine-like spinulae (Fig. 5C); (7) the mesothoracic legs subequal in length to prothoracic legs; (8) the metathoracic legs less than twice as long as head width; and, (9) the presence of setiferous tubercles on the dorsal surface of the thoracic and abdominal segments (Fig. 5F). All these character states make C. florae unambiguously diagnosed within the Copelatinae. Although the number of species involved in Alarie et al. (2022) (13 species) is relatively low considering the degree of diversity of the Copelatinae, it allows us to attempt a positioning among the three genera known from larva (i.e. Copelatus, Liopterus Dejean, 1833, and Exocelina Broun, 1886). Based on current knowledge, it seems reasonable to position C. florae within Copelatus although the presence of a large number of secondary setae on coxae and femora associated with a broadly convex frontoclypeus distinguishes it from most Copelatus species.