Teloganella Ulmer 1939

Kluge, Nikita J., Selvakumar, C., Sivaramakrishnan, K. G. & Jacobus, Luke M., 2015, Contribution to the knowledge of the mayfly genus Teloganella Ulmer, 1939 (Ephemeroptera: Ephemerelloidea), Zootaxa 4028 (2), pp. 287-295 : 288-289

Teloganella Ulmer 1939

( Figs 1–29 )

= Janohyphella Selvakumar et al. 2014 , syn. n.

Diagnosis. Larva. Labium with deep cleft present between glossae (e.g., Selvakumar et al. 2014: Fig. 9 ). Body has characteristic proportions, with thorax and legs shortened and abdomen elongated ( Wang et al. 1995: Fig. 1 ; Selvakumar et al. 2014: Fig. 2 ). Femora greatly widened, femur of each leg pair of its own characteristic shape ( Figs 13–15 ); femora with stout long blunt setae arranged in regular rows characteristic for Pantricorythi ( Kluge 2004: Fig. 89I): dorsal side of fore femur crossed by very long oblique row, continued anteriorly along outer and inner margins; dorsal side of middle femur with transverse row near base, continued along outer margin; dorsal side of hind femur without transverse row near base, with row along outer margin; middle and hind femora with row of long setae on inner margin. Tibia of each leg widened, widest in proximal part, with long setae on inner and outer margin; middle and hind tibia with patella-tibial suture terminating close to tibia apex. Claws without denticles. Hind protoptera with prominent semicircular costal projection ( Fig. 1 ). Abdominal segment II with long posterolateral projections bearing long, thin setae; segment III without posterolateral projections; segments IV–IX with long posterolateral projections bearing long, thick setae ( Fig. 1 ). Paired submedian projections present on abdominal terga III–VIII ( Fig. 20 ; Wang et al. 1995: Fig. 1 ) or IV–VIII ( Figs 1 , 23 ; Selvakumar et al. 2014: Fig. 19, 20 ). Tergalii I peg-like (as in other Ephemerelloidea retaining tergalii I), attached on projections directed posteriorly-medially ( Fig. 1 ). Tergalii II attached to posterior margin of tergum, tergalii III–V attached at mid-length of tergum ( Fig. 1 ). Dorsal lobe of tergalius II (convex and forming gill operculum, as in all Teloganodidae ) crossed by incomplete oblique desclerotized stripe ( Fig. 6 ; Wang et al. 1995: Fig. 1 ; Selvakumar et al. 2014: Fig. 15 ). Ventral lobe of tergalius II with costal branch bearing side processes turned toward middle; anal branch lacking side processes, enlarged, L-shaped, convex, partly pigmented ( Figs 2, 9 ). Dorsal lobe of each tergalius III–V concave, heart-shaped; dorsal lobe of tergalius III with longitudinal stripe separating two trachea-bearing areas ( Fig. 3 ; Selvakumar et al. 2014: Fig. 16 ). Ventral lobe of each tergalius III and IV with both branches bearing side processes ( Figs 3, 4, 10, 11 ). Tergalius V without ventral lobe ( Figs 5, 12 ). In male larva protogonostyli fused up to apex; posterior margin of ninth abdominal sternum with identical outline in male and female ( Fig. 27 ). Paracercus well developed, as long as cerci; cerci and paracercus with whorls of spine-like setae on each segment and with long, hair-like setae by sides. All three caudalii of male swollen in proximal part, but in female thinner.

Male subimago and imago. Secondary sexual features of male poorly expressed: eyes not enlarged, not divided into two portions; legs with tibia and tarsus not elongated, similar to middle and hind legs (unlike the greatly elongated and specialized forelegs found in most male mayflies). Claws on fore leg of male in subimaginal stage ephemeropteroid, in imaginal stage both blunt ( Fig. 16 ); on other legs of male (and all legs of female) claws ephemeropteroid both in subimago and imago (as in Fig. 17 ). Subimaginal mesonotum with cuticular pigmentation light; pigmented area occupies sublateroscutum and partly posterior scutal protuberances; submedioscutum densely covered with microtrichiae, medioscutum bare ( Fig. 18 ). Fore wing with fully developed venation ( Ulmer 1939: Fig. 82; Wang et al. 1995: Fig. 6 ). Hind wing with rounded costal projection medially, with Sc running nearly to wing apex, with furcation of RA and MA located near wing center and with one strong crossvein running from distal margin of costal projection, across Sc, to RA- MA furcation ( Figs 26, 29 ; Ulmer 1939: Fig. 83; Wang et al. 1995: Figs 6, 7 ). Styliger with long median process stretching along penis and covering penis from ventral side; gonostyli with relatively short 1st segment, long and slender 2nd segment, without articulated 3rd segment; penis integral, with bi-pointed apex ( Figs 25, 28 ; Wang et al. 1995: Fig. 8 ).

HYPODERMAL COLORATION. Head, thorax, legs, abdomen and caudalii with black maculae on ocher background. On legs of all pairs, femur with black and ocher maculae; on fore leg tibia with two black bands (one at base and one near middle), tarsus with black segments 2–4 and black distal part of segment 5; on middle and hind legs tibia with three black spots (one at base, one at middle and one at apex), tarsus either without black, or with black distal part of segment 5 ( Figs 13–15 ). Coloration of abdomen different in the two species ( Figs 19, 22 ). Cerci and paracercus with wide black band at apex of each segment.

Female subimago and imago (known only for T. umbrata ). Molt from subimago to imago present (in contrast to Tricorygnatha and some other taxa). Claws on all legs ephemeropteroid both in subimago and imago ( Fig. 17 ). Abdominal segment IX with long pointed posterolateral projections (as in larva), with triangular median projection of sternum ( Ulmer 1939: Fig. 85). Hypodermal maculae arranged as in male, in subimago purple.

Composition. Two species, T. umbrata and T. indica , comb. n.

Remarks. Teloganella is part of Pantricorythi. In contrast to Tricoryptera, the fore wing has an expressed tornus and the full venation characteristic for other Ephemerelloidea [see character "(6)" of Ephemerella/fg 1 in Kluge 2004], and the hind wings are present and well-developed.

Teloganella [= Janohyphella ] differs from Teloganodidae genera by the combination of characteristics in the diagnoses above, among the most notable differences being the poor expression or absence of the usual secondary sexual characteristics in the male stages of mayflies. These differences are among the reasons that some authors have excluded Teloganella from Teloganodidae in the past (e.g. McCafferty & Wang 2000, Jacobus & McCafferty 2006). Specimens of T. indica examined by Selvakumar et al. 2014 had head coloration reminiscent of that seen on the heads of male teloganodid larvae with developing dioptic compound eyes; the male eyes of T. indica , however, are holoptic.

Similar to the Teloganodidae genus-group taxa Derlethina Sartori, 2008 , Dudgeodes Sartori, 2008 and Teloganodes Eaton, 1882 (Reviewed by Sartori et al. 2008, Selvakumar et al. 2014 and Anbalagan et al. 2015), Teloganella lacks the characteristic ephemerelloid relief line on the subimaginal mesoscutum bordering the pigmented areas ( Kluge 2004: Fig. 90D), though the pigmented areas of Teloganella are relatively diminished ( Fig. 18 ).

Figures

FIGURES 1 – 12. Teloganella, details of larva. 1 – 6, Teloganella indica: 1, right part of posterior margin of metanotum and abdominal terga I – IV (tergalii II – IV removed); 2, left tergalius II (ventral view, tracheae and pigmentation of dorsal lamella not shown); 3, right tergalius III (dorsal lamella at dorsal view, detached ventral lamella at ventral view); 4, left tergalius IV, ventral view; 5, tergalius V; 6, dorsal lamella of right tergalius II, dorsal view. 7 – 12, Teloganella umbrata: 7, 8, left and right lateral sides of abdominal segment III of the same individual; 9 – 12, left tergalii II – V, ventral view (tracheae not shown).

FIGURES 13 – 17. Teloganella, legs of last instar larva before molt, with subimaginal legs visible under larval cuticle. 13 – 16, male larva of T. indica: 13 – 15, left fore, middle and hind legs, dorsal view; 16, tip of tarsus of male fore leg, with subimaginal claws and developing tissues of imaginal claws. 17, T. umbrata, tip of tarsus of female fore leg, with subimaginal claws and developing tissues of imaginal claws.

FIGURES 18 – 24. 18 – 21, Teloganella umbrata; 22 – 24, Teloganella indica. 18, cuticle of subimaginal mesonotum; 19, 22, sterna and terga of subimaginal abdomen with hypodermal coloration; 20, 23, cuticle of abdominal terga III and IV; 21, 24, labium.

FIGURES 25 – 29. 25, 26, Teloganella umbrata: 25, male subimaginal genitals (ventral view); 26, subimaginal hind wing; 27 – 29, Teloganella indica: 27, middle part of posterior margin of abdominal sternum IV of mature larva; 28, subimaginal genitals extracted from this larva (dorsal view); 29, subimaginal hind wing (extracted from this larva and spread on slide).