Apobaetis lakota McCafferty, 2000

Cruz, Paulo Vilela, Boldrini, Rafael & Hamada, Neusa, 2020, Redescription of Apobaetis lakota McCafferty, 2000 (Ephemeroptera: Baetidae) and description of two new species from Brazil, Zootaxa 4885 (2), pp. 249-258 : 250-252

Apobaetis lakota McCafferty, 2000

( Figs 1 A–1H)

A. lakota McCafferty 2000: 265 ; Meyer & McCafferty 2003: 249; Guenther & McCafferty 2005: 492; Nieto 2006: 195.

Diagnosis (modified from Nieto, 2006). Larva. 1) labrum rectangular, distal margin without shallow medial emargination; medial area of distal margin with three sockets of setae on dorsal surface ( Fig. 1A ); 2) maxillary palp long, more than 2.0× the length of galea-lacinia, segment I with the same length as galea-lacinia ( Fig. 1D ); 3) lingua subcircular with one medial lobe ( Fig. 1E ); 4) glossa distally rounded ( Fig. 1F ); 5) inner projection of labial palp segment II rounded and distally directed, segment III triangular ( Fig. 1F ); 6) tarsal claws 1.3× the length of tarsus, without row of denticles ( Fig. 1H ).

Redescription. Larva. Body: 5.0 mm; cercus approximately 2.0 mm. Head. Frons and antenna not observed on slide. Labrum ( Fig. 1A ): rectangular, broader than long; distal margin without shallow medial emargination and medial lobe; distolateral area and distal margin with robust setae; medial area of distal margin with three sockets of setae (setae broken) on dorsal surface; ventral surface with one row of thin setae on medial area of distal margin and one row of long thin setae near distolateral margin. Left mandible ( Fig. 1B ): outer and inner sets of incisors with 4 and 3 denticles, respectively; prostheca robust, bifid at apex, inner margin frayed at middle; margin between prostheca and mola concave, with frayed lobe close to subtriangular process; tuft of robust setae at base of mola present; subtriangular process wide; denticles of mola not constricted; lateral margin convex. Right mandible ( Fig. 1C ): out-er and inner sets of incisors with 3 each; prostheca slender, bifurcated at apex; margin between prostheca and mola concave; tuft of setae at base of mola absent; denticles of mola constricted (as illustrated in Cruz et al. 2018); lateral margin convex. Maxilla ( Fig. 1D ): maxillary palp long, more than 2.0× the length of galea-lacinia; segment I with the same length as galea-lacinia, segment II without distal constriction and truncated; maxillary palp with scarce, thin, simple setae scattered over surface. Hypopharynx ( Fig. 1E ): lingua subcircular and longer than superlingua, with one medial lobe and without distal tuft of setae; superlingua not expanded, with short, thin, simple setae scattered over distal margin. Labium ( Fig. 1F ): glossa narrowing slightly distally with apex rounded, longer than paraglossa; dorsal surface with one arc of setae on distal half, from inner to outer margin; ventral surface covered with thin setae. Paraglossa curved inward; dorsal surface with three robust setae on apex and one longitudinal row of four robust setae near inner margin; outer margin with one longitudinal row of six robust setae; ventral surface with one longitudinal row of nine robust setae in the middle, outer margin with one row of 12 robust setae. Labial palp with segment I approximately 1.0× the length of segments II and III combined; inner projection of segment II rounded and distally directed, outer margin of projection covered with thin, long, simple setae; outer margin of segment II covered with thin, long setae; ventral surface of segment II with one row of thin, long setae near outer margin, one row of thin long setae near inner margin of projection; segment III triangular, covered with thin, long, simple setae on outer margin, dorsal surface with one row of six robust setae, outer margin concave. Thorax. Fore and mid legs not found. Hind leg. Femur: with one row of 22 short blunt setae on dorsal margin ( Fig. 1G ); apex with two short blunt setae; ventral margin with one row of 11 short robust setae. Tibia: ventrally with one row of eight short robust setae. Patella-tibial suture from dorsal to ventral margin. Tarsus: ventrally with one row of ten short robust setae. Tarsal claws 1.3× the length of tarsus, row of denticles absent ( Fig. 1H ). Abdomen: Terga and sterna not found. Paraproct (Fig. 7 in McCafferty 2000) with one row of seven marginal spines, posterolateral extension without spines (not observed on slide). Gill, cerci and paracercus not found.

Material examined. Holotype, larva on slide, U.S.A., North Dakota, Cavalier County, Little South Pembina River near Langdon , 24.ix.1996, M. Elle, PERC, slide number 0,012,213.f.

Figures

FIGURE 1A–H. Apobaetis lakota. A. labrum (left d.v., right v.v.); B. left mandible; C. right mandible; D. maxilla; E. hypopharynx; F. labium (left d.v., right v.v.); G. detail of dorsal margin of hind femur; H. hind leg.