Apobaetis nisiae, De Lima & Cruz & Hamada, 2024

De Lima, Claudia R. T., Cruz, Paulo Vilela & Hamada, Neusa, 2024, Five new species of Apobaetis Day (Ephemeroptera: Baetidae) and updated key to nymphs, Zootaxa 5397 (1), pp. 91-115 : 104-108

Apobaetis nisiae sp. nov.

( Figures 10–12 )

Material examined. Holotype. Female nymph (on slide), BRAZIL, Rondônia, Nova Londrina, Rio Urupá , 11º02′05.8″ S, 62º08′34.1″ W, 25.viii.2016, colls. Hamada, N. and Cruz, P. V., INPA.

Description. Mature female nymph. Body: 2.4 mm (10A–C). Head. Coloration: cream. Antenna. Flagellum with minute spines on apex of each flagellomere. Labrum ( Figs. 11A–B ). Length 0.7× maximum width; distal medial margin slightly concave; dorsal surface with 3 short and blunt medial setae near distal margin, one row of long, thin, and simple setae arranged parallel to the distal margin and long, thin and simple setae scattered over all surface; ventral surface with one row of robust spine-like setae on distolateral and distal margins. Left mandible ( Fig. 11C ). Outer and inner set of incisors with 3 denticles each; prostheca robust, bifid at apex, outer lobe robust, inner lobe slender with a medial tuft of setae; margin between prostheca and mola concave, wide subtriangular process with short protuberance on distal margin; tuft of setae at base of subtriangular process; denticles of mola not constriction, with 3 elongated prominent denticles; lateral margin convex. Right mandible ( Fig. 11D ). Outer and inner set of incisors with 3 and 2 denticles, respectively; prostheca slender, bifid at apex; margin between prostheca and mola concave; tuft of setae at base mola absent; denticles of mola not constricted; lateral margin convex. Hypopharynx ( Fig. 11E ). Lingua subquadrangular, with slight apical emargination, apex covered by tuft of short setae, slightly smaller than superlingua; superlingua oval not expanded, with short and thin setae on distolateral and distal margin. Maxilla ( Fig. 11F ). Maxillary palp long, 1.8× length of galea-lacinia; segment I 0.8× length of galea-lacinia; segment II narrow slight from base to apex, with thin and simple setae over surface, apex without constriction. Labium ( Fig. 11G–H ). Glossa robust from apex to base, subtriangular at apex, longer than paraglossa, inner margin without setae; dorsal surface with one longitudinal row of 3 short spine-like setae near inner margin on apex ( Fig. 11H ); one longitudinal row of 7 robust spine-like setae on apical half, near outer margin; ventral surface covered by long, thin, and simple setae. Paraglossa curved inward; dorsal surface with one longitudinal row of 9 long spine-like setae on apical half on outer margin and one longitudinal row of 6 long and robust spine-like setae on apical half near inner margin; ventral surface with one longitudinal row of 4 long and robust spine-like setae on apical half at middle. Labial palp with segment I robust, 0.8× length of segments II and III combined, covered by micropores (not illustrated); segment II with outer margin covered by thin, long, and simple setae, inner margin bare; distomedial projection of segment II triangular and slender, apically directed; ventral surface of distomedial projection with tuft of thin, long, and simple setae; segment III subtriangular, with inner margin reduced, but present, length 0.6× width, covered by thin, long, and simple setae on outer margin, dorsally with one row of 4 robust spine-like setae in different sizes near distal margin, ventrally with 12 robust spine-like setae in different sizes on over surface. Thorax. Pigmentation. ( Figs. 10A–C ). Cream, with discreet light-brown marks scattered over mesonotum and forewing pads, legs without marks. Foreleg ( Figs. 12A– B ). Femur. Dorsal margin, anterior and posterior surface without setae; ventral margin with one row of 9 elongated spine-like setae on 2/3 basal. Tibia. Dorsal margin bare; ventral margin with one row of 10 spine-like setae. Patella-tibial suture present, restricted to ventral margin. Tarsus. Dorsal margin bare; ventral margin with one row of 14 spine-like setae. Tarsal claw. 0.6× length of tarsus, two row of minute denticles on 2/3 basal present. Middle and posterior legs similar to foreleg. Abdomen. Pigmentation ( Figs. 10A–C ). Cream, terga I–X with light brown medial mark; terga II–IX with posterior margin light cream; tergum X light cream; sterna IV–IX with posterior margin light cream; tergum X light cream. Terga ( Fig. 12C ). Sculpting of abdominal terga in form of rounded scales; tergal surface covered by micropores. Tergum IV ( Fig. 12C ). Posterior margin with minute blunt spines. Gill ( Fig. 12D ). Rounded apex, wider than base, conspicuous trachea; long, extending to beginning of fourth subsequent tergum. Paraproct ( Fig. 12E ). Without marginal and posterolateral spines. Cerci ( Fig. 12F ). Lateral short spines on all segments. Paracercus ( Fig. 12G ). Without spines.

Imago: Unknown.

Etymology. The specific name is a tribute to Dr. Nísia Verônica Trindade Lima, president of the Fundação Oswaldo Cruz from Rio de Janeiro, which coordinated, among other projects, the clinical trials of the vaccine developed by the University of Oxford and the pharmaceutical company AstraZeneca in Brazil. Noun in the genitive case.

Diagnosis. Mature nymph. 1) Distal medial margin of labrum slightly concave ( Fig. 11A ); 2) dorsal surface of labrum with 3 short and blunt medial setae near distal margin ( Figs. 11A–B ); 3) lingua subquadrangular, with slightly apical emargination, apical tuft of setae present, slightly smaller than superlingua ( Fig. 11E ); 4) maxillary palp long, 1.8× length of galea-lacinia; segment II without apical constriction ( Fig. 11F ); 5) segment II of labial palp with triangular and slender distomedial projection; segment III subtriangular, with inner margin reduced, but present ( Fig. 11G ); 6) glossa robust, from apex to base, subtriangular at apex, longer than paraglossa ( Fig. 11G ); 7) dorsal margin, anterior and posterior surface of foreleg without setae on femur; 8) claw 0.6× length of tarsus, with two row of minute denticles on 2/3 basal ( Figs. 12A–B ); 9) posterior margin of tergum IV with rounded minute spines ( Fig. 12C ); 10) paraproct without marginal spines, posterolateral extension without spines ( Fig. 12E ).

Figures

FIGURE 10. Apobaetis nisiae sp. nov., habitus of nymph. A. female nymph (d.v.). B. female nymph (v.v.). C. detail of abdomen of nymph (d.v.).

FIGURE 11. Apobaetis nisiae sp. nov. Holotype, mouthparts of nymph. A. labrum (left d.v., right v.v). B. detail of blunt medial setae near to distal margin on dorsal surface of labrum. C. left mandible. D. right mandible. E. hypopharynx. F. maxilla. G. labium (left d.v., right v.v.). H. detail of setae on apex of glossa (d.v.).

FIGURE 12. Apobaetis nisiae sp. nov. Holotype, thorax and abdomen of nymph. A. foreleg (femur on anterior surface). B. detail of two row of denticles on tarsal claw. C. posterior margin of tergum IV. D. gill. E. paraproct F. cercus. G. paracercus.