Caenis elidioi, Lima, Lucas R. C., Molineri, Carlos, Pinheiro, Ulisses & Salles, Frederico F., 2016

Lima, Lucas R. C., Molineri, Carlos, Pinheiro, Ulisses & Salles, Frederico F., 2016, Two new species of Caenis Stephens, 1835 (Ephemeroptera: Caenidae) from South America, Zootaxa 4170 (1), pp. 114-124 : 117-122

Caenis elidioi sp. nov.

( Figures 6–33 )

Caenis sp., Angeli et al. 2015: 200 (adults); Lima et al. 2016: 215 (adults and nymphs).

Diagnosis. This species can be characterized by the following combination of characters. In the imagos: 1) body length of male 2.1–3.3 mm, of female 3.5–4.3 mm; 2) base of antennal flagellum not dilated; 3) forceps pointed, sharpening abruptly and forming a long tip at the apex ( Figs. 8 , 10–13 ); 4) styliger plate with posterior margin straight to slightly subtriangular ( Fig. 10 ); 5) penes dorsally and laterally protruding ( Figs. 9–10 ). In the nymph: 1) body length of male 2.8–3.3 mm, of female 3.8–4.5 mm; 2) anterolateral margins of pronotum rounded; 3) coxal processes of middle and hind legs well-developed and semicircular, with smooth margins ( Fig. 25 ); 4) tarsal claws I and II without denticles, tarsal claw III with ca. 20 small denticles ( Figs. 31–33 ); 5) hind margin of the ninth sternite rounded ( Fig. 19 ); 6) posterolateral projections on abdominal segments V–VIII short and pointed; 7) dorsal surface of operculate gills without short and strong microspines ( Fig. 17 ). Eggs: 1) two polar caps of coiled-rope type ( Fig. 14 ); 2) oval shaped, length 1.00–1.16 maximum width.

Description. Male imago. Body length: 2.1–3.3 mm; forewing length: 2.0– 2.4 mm; foreleg length: 1.8–2.2 mm; hind leg length: 1.1–1.3 mm; cercus length: 7.1–7.4 mm.

Ratios. Leg: body size 1.17–1.38 length of foreleg; foreleg 1.59–1.83 the length of hind leg; 1st segment of foretarsus length: 2nd: 3rd: 4th: 5th = 1:4.6–5.0:2.0–2.5:1.4–1.8:1.2–1.5. Genitalia: styliger plate length 0.54–0.62 width; forceps length 8.3– 9.6 its width at distance from base; distance between extreme lateral points of forceps bases to distance of forceps length = 1.40–1.64.

Coloration. Head: whitish shaded with black dorsally, except for pale transverse medial line; venter of head whitish. Antenna: scape and pedicel whitish, shaded with gray; flagellum hyaline, shaded with black at base.

Thorax. Prothorax whitish, shaded with black dorsally, with two spots near middle; prosternum whitish, shaded with black near base of legs. Meso- and metanotum light brown, shaded with black on carinae; pleurae and sterna brown, shaded with black. Wing membrane hyaline, veins translucent except C, Sc and Rs grayish. Legs whitish with all coxae, femora and foretibiae shaded with black; subapical blackish marks present on all femora, median marks on middle and hind tibiae.

Abdomen. Whitish with black bands dorsally, paler laterally ( Fig. 6 ). Terga I–II and VII–IX darker laterally. Sterna whitish, except IX–X blackish. Pleura with tracheae strongly pigmented.

Genitalia. Sternum IX with chitinous lateral structures strongly colored. Forceps dark brown. Penes whitish, with ventral, semi-circular dark brown sclerite ( Fig. 8 ). Caudal filaments whitish translucent.

Morphology. Antenna: Base of flagellum not dilated.

Thorax. Pronotum with lateral margins straight, not protruding; prosternal longitudinal ridges forming triangleshaped structure, anteriorly open and laterally with straight margins ( Fig. 7 ).

Abdomen. Lateral filaments present on terga VII–VIII, very short; finger-like process on tergum II lacking.

Genitalia. Styliger plate subrectangular with apex slightly subtriangular (some specimens with small tubercles medially on posterior margin); central sclerite elongate dome shaped; apophyses short, triangular and pointed; lateral sclerites with broad base, more or less curved, not extended forward to central sclerite; basolateral sclerites divergent, laying distant from the lateral sclerites ( Fig. 8 ). Forceps pointed, located close to lateral margins of styliger plate, sharpening abruptly, forming long tip at apex; main axis with small denticles on ventral surface of inner margin ( Figs. 10–13 ). Penes dorsally and laterally protruding (swollen in some specimens), with tubercles ( Figs. 8–9 ), and with apical incision.

Female imago. Body length, 3.5–4.3 mm; forewing length, 2.4–2.6 mm; foreleg length, 1.4–1.8 mm; cercus length, 2.1–2.6 mm. Same coloration as in male except mesokatepisternum dark brown, with rest of mesopleural sclerites paler. Lateral filaments present on terga VII–IX, very short. Abdominal sternum IX rounded, not projected.

Egg. Length: 95–105µm; width: 90–95µm. Coloration light yellow. Oval shaped with length 1.00–1.16 maximum width. Chorion finely punctured. Two coiled-rope type polar caps with about ten terminal knobs and more-or-less eccentric position in relation to main axis ( Fig. 14 ). Micropyle funnel-shaped, narrow and long, without sperm guide ( Fig. 15 ).

Nymph ( Fig. 16 ). Length of male: body, 2.8–3.3 mm; cercus, 2.5–2.9 mm. Length of female: body, 3.8–4.5 mm; cercus, 3.7–4.2 mm.

Ratios. Mouthparts: width of maxillary palp segment I 1.6–2.0 width of segment II; length of maxillary palp segment I 1.3–1.8 length of segment II; length of maxillary palp segment I 0.8–1.0 length of segment III. Leg: length of forefemur 2.8–3.6 its maximum width.

Coloration. Head: light brown; occiput and mouthparts paler, grayish markings forming irregular net on occiput; also shaded gray behind eyes. Antenna: scape and pedicel light brown, flagellum hyaline.

Thorax. Nota brownish with black sutures. Pronotum with translucent anterolateral corners, shaded with black on anterior margin and lateral zones; with blackish paramedian dots and median elongated marks. Mesonotum with blackish macula anterior to wingbud bases, with pair of medial blackish lines. Legs yellowish, with blackish marks present on subapical zones of femora and basally on tibiae. Thoracic sterna paler.

Abdomen. Terga brownish; segments I–II with grayish band on medial area; segments VIII–X, paler medially and darker laterally. Operculate gills translucent yellowish, almost completely shaded with black and apically with 3 or 4 blackish spots. Abdominal sterna much paler, with only small grayish sublateral marks. Caudal filaments yellowish.

Morphology. Head: hind margin without setae. Mouthparts: lateral margins of labrum rounded, with long subapical setae on dorsal surface ( Fig. 20 ); mandibles with dorso-lateral row of long setae ( Fig. 22 ); lingua of hypopharynx with fore margin almost straight ( Fig. 23 ).

Thorax. Pronotum with anterolateral margins rounded and directed anteriorly; lateral margins denticulate. Legs: coxal projections well-developed and semicircular, with smooth margins ( Fig. 25 ). Ventral and dorsal margins of fore femora with short robust setae ( Fig. 26 ); middle and hind femora each with long robust setae on dorsal margin ( Figs. 27–28 ); transverse rows of spatulate setae of forefemora reduced, only with 3 or 4 setae ( Fig. 26 ). Foretarsus with one marginal row of simple pointed setae ( Fig. 31 ), middle tarsus with one marginal row of serrated setae, and hind tarsus with two rows of setae ( Fig. 33 ): one simple and one serrated ( Fig. 28, 33 ). Claws: tarsal claws I and II without denticles ( Figs. 31–32 ); tarsal claw III with ca. 20 minute denticles ( Fig. 33 ).

Abdomen. Tergum II with small projection, wide at base and posteriorly curved. Operculate gills with microtrichia from the submarginal ventral row elongated and apically frayed ( Fig. 18 ); Y-ridge complete and welldeveloped; dorsal surface smooth with long, simple setae ( Fig. 17 ). Posterolateral projections on abdominal segments V–VIII short and pointed. Sternum IX with hind margin rounded, laterally denticulate and posteriorly with long simple setae ( Fig. 19 ).

Life cycle association: The association between male imago and nymphs was made by rearing.

Distribution. Brazil: states of Bahia, Ceará State, Espírito Santo, Maranhão, Mato Grosso, Minas Gerais, Paraíba, and Pernambuco.

Etymology. This species is named to honor Elidiomar Ribeiro Da-Silva, known as “Elidio”, in recognition of his contributions to the intellectual development of authors FFS and UP, with regards to taxonomy.

Material examined. Holotype: One male imago (reared), Brazil, Bahia State, Barreiras, Vau da Boa Esperança, Córrego de Primeira Ordem Ponto 2, S12°12'21.40", W45°13'27.28", 16.iii. 2014, 556m, Lima, LRC, Knapp, W. cols. ( CZNC 6776 ) . Paratypes: Five nymphs, Brazil, Pernambuco State, Camaragibe, Rio Besouro , Estrada do Borralho, KM 0 7, PE-027, S7°59'06.4", W35°00'13.9", 16.vii.2009, 66m, Lima, LRC. col. (CEUFPE 350224). Three female imagos (reared), Recife, riacho da UFRPE, S08°00'57.4", W34°56'46.4", 22.iii.2013, 48m, Lima, LRC col. ( CZNC 6773, 6775 and 6777) ; same data as preceding except one female imago (reared) ( CZNC 6775 ) . One nymph, Brazil, Bahia State, Barreiras, Vau da Boa Esperança, Córrego de Primeira Ordem Ponto 1, S12°12'18.26", W45°13'30.09", 14.xii. 2013, 548m, Knapp, W. col ( CZNC 6779 ) ; same data as preceding except, 11 male imagos, 16.iii.2014 ( CZNC 6780 ) ; same data as preceding except, three female imagos ( CZNC 6781 ); 55 males and 15 females (light trap), Brazil, Pernambuco State, Tamandar, Riacho Mamucabas Ponto 2, próximo sede da Rebio Saltinho , S08°43'52.7", W35°10'24.8", 28.iii.2014, 38m, Lima, LRC col. (IBN) ; same data as preceding except, 92 male imagos, 17.iv.2014 ( CZNC 6782 ) ; same data as preceding except, 63 females same data except ( CZNC 6778 ) .

Additional material. Four male imagos, Brazil, Ceará State, Ubajara, Serra do Ibiapaba, Parque Nacional de Ubajara, S03°50'40.8", W40°54'35", 23.x . 2011, 858m, Silva-Neto, A; Xavier, M.; Lima, E. cols (CEUFPE). Four male imagos (Pennsylvania light trap), Brazil, Espírito Santo, Nova Venécia, entrada da cidade, Casa da Dona Ana e Seu Adalto, Rio Cricar , S18°42'54.91", W40°22'33.33", 26-27.vii.2012, Rozario, Gonçalves and Angeli cols. ( CZNC 4477 ) . One male imago (Pennsylvania light trap), Brazil, Espírito Santo, Nova Venécia, Santa Rita do Pip Nuck, Casa do Sr Pupim, Rio Cricar , S18°39'51.4'', W40°30'44.9'', 18-19.ii.2013, Rozario, Gonçalves and Angeli cols. ( CZNC 5962 ) . One male imago (Pennsylvania light trap), Brazil, Espírito Santo, São Mateus, Propriedade do Sr. Fábio Gama, Rio Cotax , S18°37'41.1", W40°6'41.6", 05-06.ii.2013, Rozario, Gonçalves and Angeli cols. ( CZNC 6004 ) . 182 male imagos, Brazil, Maranhão State, Caxias, Aldeias Altas, Riacho Limpeza, S4°38’ 26.35, W43°26’ 37.42, 21.vii.2015, Sousa, D.E. col ( CZMA). Three female imagos and 5 male imagos (light trap) Brazil, Mato Grosso State, Nova Xavantina, Bacaba, nascente, S52°21’ 48, W14°43’ 3, 06.vii.2011, Cabette , HRS. col. (UNEMAT 9563). Two female imagos and one male imago, Brazil, Minas Gerais State, Serra do Cipó, Parque Nacional da Serra do Cip, Córrego das Pedras, S19°22’17'', W43°36’02.2'', 02–03.ii.2015, Salles, FF. col. ( CZNC 6575 ) . Two male imagos Brazil, Paraíba State, Mamanguape, Rebio Guaribas, Rio Cabeça de Boi , 29.vii.2007 (CEUFPE) . 18 females imagos, Brazil, Pernambuco State, Recife, caminho para o Açude do Prata, Parque Dois Irmãos, S8°00'28.5", W34°56'54.3", 22.viii.2009, 31m, Lima, LRC col. (CEUFPE 350219); three females imagos (reared) , same data as preceding except 12.ix.2009 (CEUFPE 350225); one male imago (reared) , same data as preceding except 17.iii.2010 (CE-UFPE 350234). Three female imagos (reared), Brazil, Pernambuco State, Recife , riacho da UFRPE, S08°00'57.4", W34°56'46.4", 06.iv.2010, 48m, Lima, LRC col. (CEUFPE 350205); three nymphs , same data as preceding except 17.iv.2010 (CEUFPE 350216); four male imagos , same data as preceding except 18.xii.2012 ( CZNC 6772 ) ; same data as preceding except, one nymph and one male imago, 22.iii.2013 ( CZNC 6771, 6774 ) ; one nymph, four males and 11 females imagos (IBN 674CM and IBN 675CM) same data except 14.ii.2014 (IBN). Five nymphs, Brazil, Pernambuco State, Igarassu, Riacho Jacoc , Refúgio Charles Darwin , S07°48'57.5", W34°57'19.1", 22.iii.2010, 37m, Lima , LRC col. (CEUFPE 350227). One nymph, Pernambuco State, Goiana , Açude Santa Tereza , S07°35'33.2", W34°59'32.8", 12.xi.2011, 35m, Lima, LRC, Souza, WRM cols. (CEUFPE 350206). Two nymphs, Brazil, Pernambuco State, São João, Riacho da Barragem Inhumas, S08°58'17.3", W36°21'48.5", 13.ii . 2012, 686m, Lima, LRC, Souza, WRM cols (CEUFPE 350226). Six males and two females imagos, Brazil, Pernambuco State, Amaraji, Barragem Jaguarana, S08°21'01.6", W35°24'27.7", 05.xii . 2012, 265m, Lima, LRC col. (CEUFPE). One female imago (reared), Brazil, Pernambuco State, Rio Formoso , Riacho Gameleira, Rebio Saltinho, S08°43'12.3", W35°10'32.9", 22.xi.2012, 47m, Lima LRC, Souza, WRM cols. (CEUFPE 350231).

Figures

FIGURES 6 – 9. Male imago of Caenis elidioi sp. nov.: 6) dorsal view of abdomen; 7) ventral view of head and prothorax; 8) ventral view of genitalia (AP = apophysis; BS = basolateral sclerite; CS = central sclerite; LS = lateral sclerite; P = penis; SP = styliger plate); 9) dorsal view of genitalia (DP = dorsal projection of penes).

FIGURES 10 – 13. Genitalia of Caenis elidioi sp. nov.: 10) general view, with details of styliger plate; 11 – 13) variations in forceps.

FIGURES 14 – 15. Eggs of Caenis elidioi sp. nov.: 14) detail of surface (c = chorion; pc = polar cap); G) detail of micropyle (mc = micropylar canal). Scale bar: 10 µm.

FIGURES 16 – 19. Nymph of Caenis elidioi sp. nov.: 16) habitus; 17) opercular gill; 18) details of microtrichia from submarginal row on ventral surface of opercular gill; 19) sternum IX.

FIGURES 20 – 33. Nymph of Caenis elidioi sp. nov. 20) labrum; 21) left mandible (ventral view); 22) right mandible (dorsal view); 23) hypopharynx; 24) maxilla; 25) coxal projection of hind coxa; 26) foreleg; 27) middle leg; 28) hind leg; 29) comblike setae of middle leg; 30) details of setae of hind margin of middle femur; 31) fore tarsal claw; 32) middle tarsal claw; 33) hind tarsal claw.