Rivudiva uiara, 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 : 174-179

Rivudiva uiara sp. nov.

urn:lsid:zoobank.org:act:29E9AB92-89A4-43CB-AD13-9F84C3C78F4C

Figs 12–15

Rivudiva trichobasis – Cruz et al. 2011: 60 .

Diagnosis

IMAGO (adapted from Cruz et al. 2011). 1) dorsal portion of turbinate eyes with inner margins not parallel, divergent distally ( Cruz et al. 2011: figs 1–2); 2) length of forewing about 3.7× width ( Cruz et al. 2011: fig. 3); 3) hind wings absent; 4) terga III and VI of abdomen with one large medial red mark near distal margin ( Cruz et al. 2011: figs 4–5); 5) unistyliger cylindrical ( Cruz et al. 2011: fig. 6); 6) first segment of gonostylus short, length less than half of second segment, third segment clavate ( Cruz et al. 2011: fig. 6); 7) styliger plate concave, without spine ( Cruz et al. 2011: fig. 6); 8) gonovectis short, sinuous, not deep into segment IX.

NYMPH. The combination of the characters: 1) labrum with small medial emargination ( Fig. 12A ); 2) labrum ventral surface with simple or pectinated robust setae on distal margin ( Fig. 12A ); 3) left mandible with incisors fused at basal third ( Fig. 12B ); 4) maxillary palp segment II with small apical lobe ( Fig. 12D ); 5) hypopharynx with distomedial projection, lateral area of distomedial projection excavated ( Fig. 12F ); 6) inner arc of setae of glossa close to inner margin, outer arc of setae sinuous ( Fig. 12G–I ); 7) labial palp segment III conical, inner margin on basal half parallel to outer margin, distal half of inner margin slightly concave ( Fig. 12H ); 8) dorsal margin of forefemur with one row of long spine-setae from base to apex ( Fig. 13A ); 9) forefemur on anterior surface with small spine-like setae at middle ( Fig. 13A ); 10) patella-tibial suture absent; 11) distal margin of terga with wide spines ( Fig. 14A ).

Etymology

ʻ Uiara ʼ is the Rivers Queen in Amazonian folklore a divinity that protects waters and kills men. Name in apposition.

Material examined

Holotype BRAZIL • nymph on slide; Amazonas, Presidente Figueiredo, AM 240 Highway, Km 21, stream Recanto da Pantera; 02°02′33.15″ S, 59°50′56.13″ W; 13 Dec. 2011; P.V. Cruz leg; sand; INPA.

Paratypes BRAZIL • 5 nymphs; same collection data as for holotype; INPA .

Description

Imago

See description in Cruz et al. (2011).

Nymph

LENGTH. Body, 3.3–3.5 mm.

HEAD.Antenna. Flagellum with minute spines on apex of each segment. Labrum ( Fig. 12A ). Rectangular, length about 0.6× maximum width; distal margin with small medial emargination, one row of robust, 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 many thin setae over surface. Left mandible ( Fig. 12B ). Incisors partially cleft in two sets (fused at basal third); outer and inner set of incisors respectively with 4 + 3 denticles, outer incisor with a pectinated spine-like process; prostheca robust; margin between prostheca and mola straight; tuft of spine-like setae at base of mola absent; subtriangular process wide; denticles of mola not constricted; mola with two large denticles, inner larger than outer; outer margin convex. Right mandible ( Fig. 12C ). Incisors fused at base; outer and inner set of incisors respectively with 3 + 3 denticles and outer incisor with spine-like process; prostheca stout, bifurcated at middle, inner lobe longer and pectinate; margin between prostheca and mola straight; tuft of spine-like setae at base of mola present; denticles of mola not constricted; apex of mola with one simple seta; first process of mola triangular, second expanded and straight; outer margin convex. Maxilla ( Fig. 12D–E ). Maxillary palp 1.6× length of galea-lacinia; segment II 1.1× length of segment I; segment II inner margin with small apical lobe; ventral canine enlarged, not laterally expanded; set of distal setae of inner-ventral row pointed. Hypopharynx ( Fig. 12F ). Lingua longer than superlingua, sub-quadrangular with small distomedial projection covered by tuft of simple setae, lateral area of distomedial projection excavated; superlingua with rounded outer margin; short, thin, simple setae scattered over distal margin of lingua and superlingua. Labium ( Fig. 12G–I ). Glossa slightly broad at base, distally rounded, shorter than paraglossa; inner margin with one row of spine-like setae starting at half length; ventral surface covered by thin setae; dorsal surface with inner arc with robust setae following inner-distal margin, outer arc at base following outer margin, at apex sinuous; one robust blunt seta on apex. Paraglossa curved inward; apex with two rows of robust and long spine-like setae; outer margin with three long thin setae; dorsal surface with three longitudinal rows of setae, first near inner margin longer than half of length, distally with long robust setae and basally with long thinner setae; second with half of length of inner row, with robust long setae; and third with same length as second, distal setae long and robust, basal setae long and thin; ventral surface with one row of four setae near to ventral margin. Labial palp with segment I 0.6× 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 conical, inner margin on basal half parallel to outer margin, distal half of inner margin slightly concave; 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 thin setae.

THORAX. Foreleg ( Fig. 13A–C ). Femur length about 3.7× maximum width; dorsal and ventral margin with one row of long spine-like setae; anterior surface with one medial row of short blunt setae, one row of long spine-like setae near dorsal margin not reaching apex; posterior surface with one row of long spine-like setae near ventral margin reaching 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 absent. Tarsus. Ventral margin with one row of spine-like setae. Tarsal claws 0.4× length of tarsus, with two rows of pointed denticles reaching apex. Hind leg ( Fig. 13D–E ). Femur dorsal and ventral margin with one row of long spine-like setae; anterior surface with one row of spine-like setae near dorsal margin, one row of long spine-like setae near ventral margin; posterior surface with one row of long spine-like setae near ventral margin reaching apex. 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 0.5× length of tarsus, with two rows of pointed denticles reaching apex.

ABDOMEN. Terga ( Fig. 15 ) with all segments white (color lost in alcohol), terga I–IX with two small medial red dots; tergum III with one large medial red mark near distal margin; tergum VI with one medial red mark near distal margin; terga VII and IX with two red marks near distal margin, tergum IX with brown mark on disto-lateral margin. Posterior margin of terga with small triangular spines ( Fig. 14A ). Gills missing. Paraproct ( Fig. 14B ) with eight to nine marginal spines, posterolateral extension with spines. Cerci ( Fig. 14C ) with lateral spines on every segment. Paracercus ( Fig. 14D ) without spines.

Figures

Fig. 12. Rivudiva uiara sp. nov., holotype (INPA). A. Labrum (left v.v., right d.v.). B. Left mandible. C. Right mandible. D. Maxilla. E. Apex of maxilla v.v. (DS = dentiseta, DC = dorsal canine, MC = medial canine). F. Hypopharynx. G. Labium (left v.v., right d.v.). H. Variation of apex of segment II and segment III of labial palp. I. Shape of distal rows of setae of glossa. Not to scale.

Fig. 13. Rivudiva uiara sp. nov., holotype (INPA). A. Foreleg (femur on anterior surface). B. Detail of fore claw.C. Posterior surface of forefemur.D. Hind leg (femur on anterior surface). E. Posterior surface of hind femur. Not to scale.

Fig. 14. Rivudiva uiara sp. nov., holotype (INPA). A. Margin of tergum IV. B. Paraproct. C. Cercus. D. Paracercus. Not to scale.

Fig. 15. Rivudiva uiara sp. nov. A. Dorsal habitus of female nymph, holotype (INPA). B. Dorsal habitus of male nymph, paratype (INPA). Scale bar = 1.65 mm.