The F- 0 exuvia of Protoneura paucinervis Selys, 1886 (Zygoptera: Protoneurinae): description and diagnosis Author Ferreira, Eloiza Helena Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade, Av. André Araújo, 2.936, 69067 - 375 Manaus, Amazonas, Brazil Author Vilela, Diogo Silva 0000-0001-6510-7018 deeogoo@gmail.com Author Hamada, Neusa 0000-0002-3526-5426 Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade, Av. André Araújo, 2.936, 69067 - 375 Manaus, Amazonas, Brazil neusaha@gmail.com text Zootaxa 2024 2024-04-12 5437 2 285 293 http://dx.doi.org/10.11646/zootaxa.5437.2.7 journal article 10.11646/zootaxa.5437.2.7 1175-5326 10984805 810C4315-81B9-42E2-A1D2-D308ADBFECAD Protoneura paucinervis Selys, 1886 , description of F-0 exuvia Figs. 1−4 Material examined. 1m # F-0 exuvia (emerged in laboratory), BRAZIL , Amazonas state, S„o Sebasti „o do Uatum„, Reserva de Desenvolvimento Sustentável (RDS) do Uatum„, polo 3, Igarapé Jatuarana , ( 2º16’03.5’’ S 58º54’12.2’’W , 30 m asl ), collected on 15.ix.2022 , emerged on 10.x.2022 , A. Pes , J.O. da Silva , G. Mendes , I. Soliz , R . Pinedo leg., INPA . 1m # BRAZIL (died before emergence), Amazonas state, S„o Sebasti„o do Uatum„, Reserva de Desenvolvimento Sustentável (RDS) do Uatum „, polo 3, Igarapé Jatuarana , ( 02º20’41.5” S , 58º56’29.52” W ), 30.xiii.2023, J.O. Silva , E.H. Ferreira , D.O. Franco leg. Description. Exuviae dark brown with pale spots ( Fig. 1a ); slender; trochanter pale colored; femora with lightbrown bands; caudal gills long, about 0.5−0.66 of total body length ( Figs. 1a , 2c ). Head ( Figs. 1−3 ). Subpentagonal, 0.5 as long as wide, wider than thorax and abdomen ( Fig. 1a ). Clypeus, frons and vertex smoothly rounded, glabrous lacking setae. Occipital margin widely concave, nearly straight at middle; cephalic lobes rounded, bulging at the postocular portion, with 7–10 spines ( Figs. 1 a−b). Compound eyes slightly wider than long, laterally prominent ( Figs 1 a−b). Antenna ( Fig. 1c ) moderately long and filiform, 7-segmented, scape and pedicel dark-brown, cylindrical, remainder (flagellum) uniformly light brown; 3rd antennomere the longest; proportional antennomere length: 0.3, 0.55, 1.0, 0.5, 0.4, 0.4, 0.2. Prementum-postmentum articulation surpasses posterior margin of prothoracic coxae; prementum ( Fig. 1d ) longer than wide, pentagonal, lateral margins straight, divergent apically, laterodorsally with a row of eight or nine spiniform setae; ligula tip prominent, blunt, finely crenulated; one long premental setae on each side of midline. In dorsal view, labial palps ( Fig. 2a ) with five long setae each, in ventrolateral view, palpal lobe ( Fig. 2b ) squared, bearing three strong teeth; ventral palpal branch with a well-developed hook, its anterior margin finely crenulate; ventral margin of palp finely crenulate; movable hook almost the size of labial palp, lacking basal setae, acute apex. Maxilla ( Figs. 2 c−d): galeolacinia with five teeth, medial one slightly longer, with a basal row of long setae below teeth. Mandibles formula R 1+2345 y a / L 1+2345 a b, where b=a ( Figs. 3 a−d). FIGURE 1. Protoneura paucinervis , F-0 exuviae: (a) habitus, dorsal view; (b) close-up of right postocular lobe; (c) antenna; (d) prementum, dorsal view. Thorax ( Fig. 1a ). Pronotum dark brown with small pale spots, subtrapezoidal, widest at base; posterior margin convex. Meso- and metathorax with the same coloration as the prothorax; anterior and posterior wing sheaths subequal in size, arranged parallel to the abdomen, reaching mid S6. Legs long, apex of metathoracic femur reaching S6 when extended, dark brown with apical, medial and basal bands on all femora and tibiae; dorsal portion of femora with a row of 3–6 spiniform setae; tarsi about 0.40 of tibiae length, claws with acute apex. Abdomen ( Figs. 1a , 4 ). Uniformly dark-brown colored, with small pale dots, and a medial abdominal pale stripe; covered with minute spines on dorsal and ventral surfaces, more densely spread on S7–10. In ventral view ( Fig. 4 a−b), male gonapophyses sharply pointed, short, tips reaching sternum 10, bearing no spines. Cercus globose ( Fig. 4b ), with rounded tip. Caudal gills ( Fig. 4c ) longer than wide, measuring nearly 0.5–0.66 of total body length; nodus at 0.77 of gill length; ventral margin of antenodal portion of lateral gill with>50 spines, increasing in size towards apex; dorsal margin of antenodal portion of median gill bearing 10–15 spines, increasing in size towards the apex, plus>10 long white setae (not detectable unless the light source is directed at an extremely low angle). Measurements. TL (with gills): 9.48; AL: 5.4; AntL: 1.4; PfL: 1.63; MsfL: 1.83; MtfL: 2.2; MHW: 2.7; LG: 4.9; MG: 4.1. FIGURE 2. Protoneura paucinervis , mouthparts of F-0 exuvia: labial palp, (a) dorsal view, (b) ventral view; maxilla, (c) ventral view, (d) lateral view. FIGURE 3. Protoneura paucinervis , mouthparts of F-0 exuviae: (a–b) internal view of mandibles; (c–d) ventral view of mandibles. Comparative Diagnosis . The larva of P. paucinervis can be distinguished from the other known Protoneura larvae by the following character combination (see Table 1 , other species in squared brackets): overall body coloration dark-brown [shared with P. capillaris and P. romanae ; remainder species paler]; 7-segmented antennae [some specimens of P. ailsa bearing 6]; palpal lobe squared, bearing three strong teeth [other species with 4 strong teeth or several minute teeth]; 5 palpal setae [ 3 in P. caligata , 3–5 in P. ailsa and 5–6 in P. romanae ]; wing pads reaching basal S6 [shared with P. aurantiaca and P. capillaris ]; nodus of lateral gills at 0.77 of its length [similar in P. aurantiaca and P. cupida ]. Despite all the morphological differences between these species, we advise caution while identifying larvae of Protoneura , as the hitherto known described immatures are very similar to each other, being only separated by a long combination of characters (as shown in Table 1 ). It is important to check the adult morphology, when possible, to ensure the correct identification of the specimens.