Rivudiva amazona, Cruz & Boldrini & De Lima & Hamada, 2022

Cruz, Paulo Vilela, Boldrini, Rafael, De Lima, Cláudia R. T. & Hamada, Neusa, 2022, It is a mess! How many species are in Rivudiva trichobasis Lugo- Ortiz & McCafferty, 1998 (Ephemeroptera: Baetidae)?, European Journal of Taxonomy 789 (1), pp. 153-191 : 162-164

Rivudiva amazona sp. nov.

urn:lsid:zoobank.org:act:595B6165-BC4E-4AFB-BF4F-CD6FB5C22432

Figs 4–7

Rivudiva trichobasis – Falcão et al. 2011: 539.

Diagnosis

NYMPH. The combination of the characters: 1) labrum with distal margin straight ( Fig. 4A); 2) labrum ventral surface with robust, distally bifid, eventually pectinated, setae on distal margin ( Fig. 4A); 3) left mandible with incisors fused at basal third ( Fig. 4B); 4) maxillary palp segment II with reduced apical lobe ( Fig. 4D); 5) hypopharynx without distomedial projection ( Fig. 4F); 6) glossa oval with inner and outer arcs of setae not sinuous and close to margins ( Fig. 4G–H); 7) labial palp segment III robust, conical and apically pointed ( Fig. 4G); 8) dorsal margin of forefemur with one row of long setae from middle length to apex ( Fig. 5A); 9) forefemur on anterior surface with long blunt setae at middle ( Fig. 5A); 10) patella-tibial suture present; 11) distal margin of terga with elongated triangular spines ( Fig. 6A).

Etymology

The name ʻ Amazonas ʼ was given to native South American women after they attacked a conquest expedition. This species is named in honor of these brave native women. Name in apposition.

Material examined

Holotype

BRAZIL • nymph on slide; Roraima, Caroebe, River Caroebe , vicinal 05; 00°54′47.3″ N, 59°34′19.9″ W; 19 Mar. 2013; P.V. Cruz, N. Hamada, R. Boldrini and G. Petronilo leg.; sand; INPA.

Paratypes

BRAZIL • 14 nymphs; same collection data as for holotype; INPA • 2 nymphs on slide; same locality as for holotype; 12 Mar. 2018; P.V. Cruz and I.O. Fernandes leg.; sand; INPA .

Additional material

BRAZIL • 4 nymphs; Roraima, BR-170, 41 Km turn to BR-432, old bridge, right from Vila de Santa Rita ; 02°08′59.9″ N, 60°40′39.9″ W; 28 Mar. 2012; P.V. Cruz, N. Hamada, R. Boldrini and G. Petronilo leg.; sand; INPA • 3 nymphs; Roraima, Pacaraima, River Ereu ; 04°02′02.9″ N, 61°23′09.5″ W; 26 Mar. 2012; P.V. Cruz, N. Hamada, R. Boldrini and G. Petronilo leg.; INPA • 3 nymphs; Roraima, São João da Baliza, Ramal 27, stream Lajinha ; 01°00′59.7″ N, 59°55′53.1″ W; 24 Mar. 2012; P.V. Cruz, N. Hamada, R. Boldrini and G. Petronilo leg.; INPA • 1 nymph; Roraima, Caroebe, Ramal 37, River Caroebe , Cachoeirinha farm; 00°57′09.2″ N, 59°37′00.5″ W; 23 Mar. 2012; P.V. Cruz, N. Hamada, R. Boldrini and G. Petronilo leg.; INPA .

Description

Nymph

LENGTH. Body, 3.3–3.5 mm.

HEAD. Antenna. Scape and pedicel with spine-like setae; flagellum with minute spines on apex of each segment. Labrum ( Fig. 4A). Rectangular, length about 0.6× maximum width; distal margin straight, one row of robust, distally bifid, eventually pectinated, setae from lateral to middle of distal margin; one row of thin bifid setae on distal margin not reaching distolateral margin; dorsal surface, near distal margin, with one row of thin setae, and many thin setae over surface (not illustrated). Left mandible ( Fig. 4B). Incisors partially cleft in two sets (fused at basal third); outer and inner sets of incisors respectively with 4 + 3 denticles, outer incisor with spine-like process; prostheca robust and pectinated; margin between prostheca and mola straight; tuft of spine-like setae at base of mola present; subtriangular process wide; denticles of mola constricted; mola with one large denticle; outer margin convex. Right mandible ( Fig. 4C). Incisors fused at base; outer and inner sets of incisors respectively with 3 + 3 denticles, outer incisor with spinelike process; prostheca stout, bifurcated at apex, inner lobe longer; margin between prostheca and mola almost straight; tuft of spine-like setae at base of mola present; denticles of mola not constricted; apex of mola with one simple setae; first process of mola rounded, second expanded and straight; outer margin convex. Maxilla ( Fig. 4D–E). Maxillary palp 1.7× length of galea-lacinia; segment II 1.1× length of segment I; segment II inner margin straight, outer margin on apex straight, reduced apical lobe; ventral canine enlarged, not laterally expanded; set of distal setae of inner-ventral row rounded. Hypopharynx ( Fig. 4F). Lingua longer than superlingua, sub-quadrangular without distomedial projection covered by tuft of simple setae; superlingua with rounded outer margin; short, thin, simple setae scattered over distal margin of lingua and superlingua. Labium ( Fig. 4G–H). Glossa oval, slightly broad at base, distally rounded, shorter than paraglossa; inner margin without row of setae; ventral surface covered by thin setae; dorsal surface with inner arc close to inner margin, and outer arc not sinuous and close to outer margin; one small robust blunt seta on apex. Paraglossa curved inward; apex with one row of robust and long spine-like setae; outer margin without setae; dorsal surface with two longitudinal rows of setae, one near to inner margin, one near to outer margin, distally with long robust setae; ventral surface with one row of five setae near to ventral margin. Labial palp with segment I 0.8× length of segments II and III combined; inner distal protuberance of segment II rounded, with almost straight distal margin, covered with thin setae; segment III robust, conical, and apically pointed; outer margin with short thin setae, dorsal surface with one row of short spine-like setae near inner margin, ventral surface with one row of setae.

THORAX. Foreleg ( Fig. 5A–C). Femur length about 2.6× maximum width; dorsal row of setae from distal half to apex; anterior surface with one medial row of long blunt setae, one row of short blunt setae near dorsal margin; posterior surface with one row of long spine-like setae near ventral margin from base to apex, and one medial row of long spine-like setae. Tibia. Dorsally bare; ventral margin with one row of long spine-like setae, patella-tibial suture present. Tarsus. Ventral margin with one row of spine-like setae. Tarsal claws 0.4× length of tarsus, with two rows of conical denticles not reaching apex. Hind leg ( Fig. 5D–E). Femur anterior surface with one row of spine-like setae near dorsal margin reaching apex, one row of long spine-like setae near ventral margin reaching apex, one row of spine-like setae near middle; posterior surface with one row of spine-like setae near ventral margin from base to apical third. Tibia. Dorsally bare; ventral margin with one row of small blunt setae, patella-tibial suture present. Tarsus. Ventral margin with one row of small blunt setae. Tarsal claws 0.4× length of tarsus, with two rows of small conical denticles not reaching apex.

ABDOMEN. Terga ( Fig. 7) with all segments white (color lost in alcohol), terga I–IX with two small medial dots, sometimes dots absent; tergum I with one large dot on disto-lateral margin (rare); eventually tergum II, III and IX darker or with large brown pigmentation; terga III and VI with one large medial mark near distal margin; terga VI and VII with disto-lateral transversal brown mark (rare). Posterior margin of terga with elongated triangular spines ( Fig. 6A). Gills oblong, longer than next segment, with one medial trachea pigmented. Paraproct ( Fig. 6B) with nine to eleven marginal spines, posterolateral extension with spines (broken in holotype and illustrated). Cerci ( Fig. 6C) with lateral spines on every segment. Paracercus ( Fig. 6D) without spines.

Comments

The differences in deepness of the curvature of the distal lobe on the maxillary palp segment II is related to the slide artifact ( Fig. 4E).