Latineosus sigillatus (Molineri, 2014) Molineri, 2014

Angeli, Kamila Batista, Salles, Frederico Falcão, Paresque, Roberta, Molineri, Carlos & Lima, Lucas Ramos Costa, 2016, Stage description, new combination and new records of Neotropical Brachycercinae (Ephemeroptera: Caenidae), Zootaxa 4088 (2), pp. 268-278 : 272-274

Latineosus sigillatus (Molineri, 2014) , new combination

( Figs. 2–4 )

Alloretochus sigillatus Molineri 2014: 142 , Angeli et al. 2015: 200

Adults and egg. Adequately described by Molineri (2014).

Nymph. Diagnosis. 1) Compound eyes strongly produced dorsally ( Figs. 3A, B, C ); 2) Anterior margin of compound eyes not extending anterior of base of middle ocellar tubercle ( Fig. 3C ); 3) Lateral ocellar tubercle with length subequal to basal width, triangulate in lateral view, apex rounded; 4) Labrum trapezoidal with lateral margin nearly straight; 5) Operculate gill ventrally without submarginal microtrichia; 6) Abdominal segment VI with a pair of projections not overlapping medially ( Fig. 4B, C ); 7) Abdominal segments VII-VIII without projections.

Description. Coloration: General coloration yellowish brown. Head with diffuse dark brown marks on vertex ( Fig. 3A ); antenna pale. Thorax ( Fig. 2B ) with pronotum with dark brown mark in medial region; posterior margin of mesonotum dark brown; metanotum shaded with brown; ventrally pale; legs pale. Abdomen ( Fig. 2B ) dorsally with segments I and II shaded with light brown and with dark brown marks in medial region; segments VII–X with dark brown marks in medial region; ventrally pale; operculate gill with Y-ridge dark brown. Caudal filaments pale with apex shaded with light gray.

Lengths (mm): body, 3.9–4.7; caudal filaments, 1.4–2.2; antenna, 0.9–1.1.

Head: Occiput relatively densely covered with long setae. Compound eye ( Figs. 3A, B, C ) strongly produced dorsally; anterior margin not extending anterior of base of middle ocellar tubercle. Lateral ocellar tubercle ( Fig. 3C , 4A ) length subequal to basal width, triangulate in lateral view, apex rounded. Middle ocellar tubercle ( Fig. 3A, B , 4A ) tapered-conical in dorsal view; length 0.7 × of basal width, and 0.7 × length of lateral ocellar tubercle; apex rounded. Antenna with pedicel 1.0 × length of scape, with 4 or 5 setae on pedicel. Labrum trapezoidal with lateral margin nearly straight. Hypopharynx with superlingua subovate with lateral margin moderately and convexly produced. Maxilla ( Fig. 3D ) with galea-lacinia length 2.3 × basal width; palp segment I width 1.6 × width of segment II; segment II 1.4 × length of segment I, with seven long, stout setae along inner margin.

Thorax: Pronotum with anterior margin moderately emarginate; lateral margin not forming distinctly convex ridge, without angulate expansion. Propleuron partially visible in dorsal view. Legs. Ratios of lengths of body: foreleg: midleg: hindleg—3.6: 1.0: 1.7: 1.8. Ratios of lengths of forefemur: tibia: tarsus: claw—2.1: 1.0: 1.1: 0.7. Ratios of length of hindfemur: tibia: tarsus: claw—1.7: 1.0: 1.0: 0.5. Foreleg. Femur. Dorsally with few long setae and many short setae; ventrally with sparse row of short setae and many long setae on basal third; length of long setae 0.5–1.5 × width of femur. Tibia. Ventral margin with row of about seven setae as long as, or shorter than, width of tibia; posterior surface with some scattered setae measuring 1.2–1.5 × width of tibia, but not arranged in distinct row. Tarsus. Ventral margin with row of about 12 setae as long as, or shorter than, width of tarsus; anterior and posterior surfaces with some setae as long as 1.8 × width of tarsus, not in distinct rows. Hindleg. Femur length 7.0 × width; outer margin with row of short setae and few setae 1.5 × longer than width of femur; inner margin with short setae. Tibia. Outer margin with long, fine setae measuring in length about 2.8 × width of tibia; inner margin with few fine, simple setae. Tarsus. Outer margin bare; inner margin with row of about 6 fine, simple setae. Tarsal claw length 7.4 × basal width.

Abdomen: Terga. Posterolateral projection V length 3.4 × basal width ( Fig. 4B, C, D ); projection VI with distal half with outer margin posterior to inner margin in dorsal view, and with apex rounded, pair of projections not overlapping medially ( Fig. 4B, C ); segments VII–IX without projections. Sterna. Sternum IX with posterior margin truncate. Operculate gill ( Fig. 4B, C, E ). Length 1.2 × width; dorsum with lateral region with some long setae onefifth to one-third length of gill; posteromedial corner with row of long marginal setae measuring up to one-third length of gill; posterolateral corner with marginal setae one-sixth to one-fourth of gill and not longer than posteromedial corner setae; Y-ridge weakly developed, narrow, indistinct; ventral submarginal microtrichia absent.

Material examined. 8 nymphs, BRAZIL, Espírito Santo, São Mateus, Rio Cotaxé, Japira, S 18º34'39.1" / W 40º16'58.0", 18/iv/2013, F.F. Salles, E. Rosário, cols.; 6 male imagos from Pensilvânia light trap, same data as previous, except: 22–23/xi/2012. 18 male imagos from Pennsylvania light trap, BRAZIL, Espírito Santo, Nova Venécia, Rio Cricaré, Santa Rita do Pip Nuck, S 18°39'51.4'' / W 40°30'44.9'', 18–19/iv/2012. 94 male imagos from Pennsylvania light trap, BRAZIL, Espírito Santo, São Mateus, Rio Cotaxé, Sr. Gama farm, S 18°37'41.1" / W 40°6'41.6", 20–21/xi/2013. 35 male imagos, BRAZIL, Rio Grande do Sul, Bossoroca, Barra de Angico, Rio Piratinim, 28.vi.2009, S 28o 32' 26" W 54o 57' 30", AMO Pes col.

Figures

FIGURE 2. Latineosus sigillatus. A, B. Habitus, nymph.

FIGURE 3. Latineosus sigillatus. A. Lateral and middle ocellar tubercle, dorsal view. B. Lateral and middle ocellar tubercle, ventral view. C. Lateral and middle ocellar tubercle, lateral view. D. Maxilla.

FIGURE 4. Latineosus sigillatus. A. Head, dorsal view. B, C. Operculate gills and abdominal posterolateral projections. D. Detail of abdominal posterolateral projections. E. Detail of operculate gill.