Enderleina bifasciata, Hamada, N., Silva, J. O. & Pedroza, M. K., 2016

Hamada, N., Silva, J. O. & Pedroza, M. K., 2016, A new species of Enderleina Jewett (Plecoptera, Perlidae) from Amazonas State, Brazil, Zootaxa 4098 (2), pp. 392-400 : 393-399

Enderleina bifasciata n. sp. ( Figs. 4–27 )

Holotype, male, Brazil, Amazonas, Barcelos County, Parque Estadual Serra do Aracá, Anta stream (camp at the base of the mountain ). 0 0° 52´44.9” N, 63° 27´14.2” W, 150 m. a.s.l.), Malaise trap, collectors: Silva, J. O.; Nessimian, J. L.; Neiss, U. G.; Santos, A. P. M.; Ferreira Junior, N. 1–3/08/2009 ( INPA) .

Etymology. The specific epithet of the new species derived from two latin words: bi = two; fasciat = banded, in reference to the paired, narrow bands on the mesal region of the pronotum.

Diagnosis. The only known specimen of E. bifasciata n. sp male is distinguished from all known species of the genus by the orange pronotum with a mesal pair of narrow, brown bands, each band running parallel to the ecdysial line ( Figs. 4 , 7 ). Penial armature with three processes ( Figs. 22–25 , 26, 27 ): a) median sclerite, widest at its base, gradually tapering towards the distal region and abruptly acuminating in its apical portion ( Figs. 22, 23 , 26, 27 ); b) a pair of basolateral spines bifurcated, one arm arranged ventrally and the other dorsally ( Figs. 22–24 , 26, 27 ); dorsal arm slightly longer than the ventral arm, both with length surpassing half the total length of the median sclerite ( Figs. 24 , 26, 27 ); both arms with subapical region fan-like in shape and apical region spine-like in shape (inserted on the inner margin of the fan-like subapical region) ( Figs. 22, 23 , 26, 27 ).

Description. Male. Total length: 12.3 mm (not including cercus); forewing length: 12.6 mm; posterior wing length: 10.8 mm. General color (in 80% ethanol), in dorsal view, yellowish light brown, except head, mostly dark brown and pronotum orange ( Fig. 4 ); in lateral and ventral views, yellowish white ( Figs. 5, 6 ). Head ( Fig. 7 ): dark brown from parietal region to frons until the anterior ocellus, except external margins of these regions, which are yellowish white; M-line faint, narrow, brownish orange in color with its central region in contact with the anterior ocellus; narrow orange area along basal half-length of the epicranial suture and along the meso-posterior margin of the occiput; tubercle near the external margin of each lateral ocellus yellowish brown; eyes black; ocelli surrounded by a narrow orange area, anterior ocellus less than half the diameter of lateral ocelli; epicranial line surpassing the anterior margin of the lateral ocelli; gena and head ventral region, including maxillary and mandibular palps yellowish white; antennae long, with flagellomere becoming darker (greyish brown) toward the end, inner margin of scape with a small, dark brown area on the distal region. Pronotum rectangular, anterior margin convex ( Fig. 7 ); orange in color, with a pair of narrow, brown bands, on the mesal region (one band located on each side of the ecdysial line), anterior and distal regions of the bands do not reach the pronotum margins. Meso- and metanotum light brown, with dark hairs ( Fig. 8 ). All legs light brown ( Figs. 11–13 ) except the external margin of the trochanter, distal region of femur and proximal internal region of tibia, all of which are dark brown. Anterior ( Fig. 14) and posterior wings ( Fig. 15) light brown. Abdomen and cerci light brown ( Figs. 5, 6 , 9 ); abdomen hairy, latero-dorsal region of tergites VI–VIII with a pair of elongated areas, dark brown ( Fig. 9 ), pattern results from a dense group of brown hairs ( Fig. 10 ). Tergite X, in dorsal view ( Fig. 17 ), with two groups of strong spines denominated as sensilla basiconica by Stark (1989) ( Fig. 19 , indicated by the arrow), distributed irregularly anteriorly, except medially). Tergite IX, lateral margin projected posteriorly ( Fig. 18 ). Sternite IX ( Fig. 16 ), in ventral view, longer than wide, with brown hairs, meso-distal region of the sternite with hairs longer and stronger than those on the other regions; each side of this sternite bearing one large, whitish area (indicated by the arrows in Fig. 16 ), posteriorly; hammer rounded, flat and pale. Paraproct with apical region acuminated and sclerotized ( Fig. 20 ), with a subbasal spine inserted on its anterior margin, directed downward ( Fig. 21 , indicated by the arrow). Penial armature with three processes: a) median sclerite and b) a pair of basolateral spines ( Figs. 22–24 , 26, 27 ). Median sclerite ( Figs. 23, 24 , 26, 27 ) composed of a wide, elongated distal body and a pair of lateral arms, anteriorly; body widest at its base, gradually tapering towards distal region and abruptly acuminating at its apical region; body with a shallow keel ventrally (better seen in posterior view, Fig. 25 ), arrow indicates ventral side of the median sclerite body); arms of the median sclerite divergent proximally, twisted toward dorsal region distally ( Figs. 23 , 27 ). Each basolateral spine bifurcated, one arm positioned ventrally and the other dorsally ( Figs. 24–27 ); dorsal arm slightly longer than the ventral arm, both with length more than half the total length of the median sclerite ( Figs. 24 , 27 ); both arms with subapical region fan-like in shape and apical region spine-like in shape (inserted on the inner margin of the fan-like, subapical region) ( Figs. 22, 23 , 26, 27 ); distal margin of fan-like region of the ventral arm straight, perpendicular to the longitudinal body plain ( Figs. 23 , 27 ); distal margin of the fan-like region of the dorsal arm lobulated on its inner margin (at the base of the spine-like projection) and not straight, inclined anteriorly at an angle of 45° to the longitudinal body plain ( Figs. 22 , 26 ). Membrane of aedeagus with distinct setae.

Female and nymph: unkown.

Taxonomic comments. Enderleina bifasciata n. sp. is the only described species in the genus with a pair of dark bands on the pronotum, the other described males in the genus ( E. froehlichi Ribeiro-Ferreira, 1996 , E. khalzeni Derka & Tierno de Figueroa, 2013, E. preclara Jewett, 1960 , and E. yano ) have the pronotum unmarked, orange or dark with orange ( Jewett 1960, Ribeiro-Ferreia 1996, Stark et al. 2009, Derka & Tierno de Figueroa 2013).

Males of E. bifasciata , E. khalzeni , and E. froehlichi share the two large pale areas laterally on sternum IX. The body of the median sclerite of the penial armature of the new species and that of E. froehlichi are wide at the midpoint of their length and are apically acuminate. However, in the latter species, the body of the median sclerite, in ventral view, has the anterior margin (between the median sclerite arms, proximally) projected anteriorly (illustrated but not described by Ribeiro-Ferreira 1996); the external margin of this projected region has a row of strong spines that continues until the subapical region of the median sclerite.

Among all the described species, E. bifasciata n. sp. is most similar to E. khalzeni . Both species have tergite X with rounded median distal region and lighter patch on the mid-posterior region with or without short, thin hairs. The basiconica sensillae in both species are widely and irregularly distributed. The two arms of the basolateral spines of both species are positioned in a dorsoventral plane and the subapical region of the ventral arm has its subapical region fan-like in shape and the apical region has a long spine-like projection (inserted on the inner margin of the fan-shaped region). The dorsal arm in the new species also has its subapical region fan-like in shape and it is slightly longer than the ventral arm, but in E. khalzeni this arm is blade shaped and it is much longer than the ventral arm (Derka & Tierno de Figueroa 2013).

Although the new species was collected in a remote region with difficult access in Amazonia, hopefully additional specimens will become available to understand intraspecific variability and to allow for the morphological description of the female and nymph. This information will be important to provide a basis for future phylogenetic analysis of the genus and to increase our knowledge of the biology of this rare genus of northern Amazonia.

Bionomics. Only one male specimen of the new species was collected using a Malaise trap ( Fig. 2 ) placed over the Anta Stream in Serra do Aracá State Park, Barcelos County, Amazonas, Brazil. This stream is located at the base of the Aracá Mountain Range ( Fig. 3 ) at 150 m. a.s.l. The water of the stream is stained black, acidic ( pH 4.5), with low conductivity (10 µScm -1), and was 23o C at the time of sampling. At this site the stream is 5– 10 m wide with a sandy and rocky bottom with boulders ( Figs. 2, 3 ). No nymphs of this genus were collected from this stream.

Figures

FIGURES 4 – 6. Enderleina bifasciata n. sp., male, general habitus. 4. Dorsal view. 5. Lateral view. 6. Ventral view.

FIGURES 7 – 13. Enderleina bifasciata n. sp., male. 7. Head and thorax, dorsal view. 8. Meso and metanotum, dorsal view. 9. Abdominal segments VI – VIII, lateral view. 10. Abdomen, dorsal view. 11 – 13. Legs, anterior, median, and posterior, respectively.

FIGURES 22 – 25. Enderleina bifasciata n. sp., penial armature. 22. Dorsal view. 23. Ventral view. 24. Left lateral view. 25. Posterior view; arrow indicates the ventral side of the median sclerite. bms = body of median sclerite; ams = arms of median sclerite; vas = ventral arm of basolateral sclerite; das = dorsal arm of basolateral sclerite.

FIGURES 26 – 27. Enderleina bifasciata n. sp., penial armature. 26. Dorsal view. 27. Ventral view. bms = body of median sclerite; ams = arms of median sclerite; vas = ventral arm of basolateral sclerite; das = dorsal arm of basolateral sclerite.

FIGURES 16 – 21. Enderleina bifasciata n. sp., male. 16. Abdomen distal region, in ventral view. 17. Abdomen, distal region, in dorsal view. 18. Abdomen distal region, in lateral view. 19. Tergite X, lateral region of posterior margin; arrow indicates the sensilla basiconica. 20. Paraprocts, in postero-lateral view. 21. Paraprocto, lateral view, arrow indicates the subbasal spine.

FIGURES 1 – 3. 1. Map of South America with detailed area containing the Anta Stream location (star), type locality of Enderleina bifasciata n. sp. (Plecoptera: Perlidae), in Amazonas State, Brazil. 2. Malaise trap (indicated by the arrow) placed over the Anta Stream. 3. Downstream of Malaise trap site with Aracá Mountain Range in the background.