Anafroptilum odontostylus, Kluge, Nikita J. & Novikova, Eugenia A., 2017

Kluge, Nikita J. & Novikova, Eugenia A., 2017, Occurrence of Anafroptilum Kluge 2012 (Ephemeroptera: Baetidae) in Oriental Region, Zootaxa 4282 (3), pp. 453-472 : 463-468

Anafroptilum odontostylus sp. n.

( Figs 54–85 )

Etymology. Referring to denticle on inner side of the first segment of male imaginal gonostylus ( Fig. 79 )

Material examined. Holotype: L-S-I ♂ {specimen [XIII] (1) 2015}, THAILAND, Mae-Hong-Son Province , river Pai upstream of Pai, 9.II.2015, coll. N. Kluge & L. Sheyko . Paratype: the same locality, 8.II.2015, coll. N. Kluge & L. Sheyko: L-S-I ♂ .

Descriptions. Larva. Cuticular coloration. Head with light brown and colorless areas. Pronotum and mesonotum with light brown and colorless areas; protoptera light brownish with colorless stripes corresponding to longitudinal veins ( Fig. 56 ). Metanotum and thoracic pleura light brown, thoracic sterna and membranes colorless. Legs nearly colorless; apex of femur, base of tibia and outer side of tarsus diffusively tinged with light brownish. Abdomen with light brown and colorless areas identical in two examined individuals ( Fig. 54 ): terga II and VII with most extensive brown coloration, terga III and V with light median area, other terga lighter; abdominal sterna at most part colorless, with anterior margins brown. Cerci at most part light brownish, colorless at base, with posterior margin of each 4th segment slightly darkened; paracercus lighter than cerci ( Fig. 54 ). Each swimming seta of cerci and paracercus brown proximally, colorless distally.

Hypodermal coloration. Unknown (probably not expressed).

Structure. Frons between antennae with flat elevation; frontal suture relative long and obtuse-angled (as in Fig. 37 ). Labrum of usual shape; dorsal surface with irregularly situated setae [without constant pair of submedian setae and/or pair of latero-distal setal rows – see Anafroptilum (9)] ( Figs 60 , 76 ). Both mandibles with incisor and kinetodontium deeply separated [see Anafroptilum (10)]; planes of incisor, kinetodontium and prostheca perpendicular to plane of mandible ( Figs 61–62 ); denticles of incisors, kinetodontia and prosthecae similar to that of A. orthostylus (as in Figs 38–39 ). Molar processes of left mandible as long as distal molar projection; each process terminated by short apical lamella ( Fig. 63 : al). Maxilla with 3 canines, 3 dentisetae, 4–5 setae proximad of dentisetae and 9–10 setae of inner ventral row; all canines, dentisetae and setae slender, pointed and bent at the same direction ( Fig. 77 ) [see Anafroptilum (12)]. Maxillary palp 3-segmented, all three segments of subequal length ( Fig. 77 ). Labium with glossae and paraglossae not narrowed near bases; setae of glossa not shortened; setae of dorso-median row of paraglossa located near median margin; labial palp with 3rd segment widened apically and truncate ( Fig. 78 ) [see Anafroptilum (2)].

Vestiges of hind protoptera represented by blunt projections. Legs as in A. kazlauskasi ( Kluge 2012: Figs 38–40 ): femora nearly parallel-sided, fore femur widest at middle, middle and hind femora widest at apex; apex of each femur finely serrate ( Fig. 59 ); each femur without stout setae on outer margin and apex; only inner margin with few small stout setae [see Anafroptilum (14)]; fore tibia without patella-tibial suture, middle and hind tibia with patella-tibial suture [see Anafroptilum (1)]; each tibia with short ark of fine setae at outer side near base; outer side of tibia and tarsus without stout setae, inner side of tibia and tarsus with sparse spine-like setae. Claw with two equal regular rows of small denticles, reaching less than 1/2 of claw length ( Fig. 64 ).

Abdominal terga and sterna with small denticles and sparse narrow scales ( Figs 65–68 ); sterna with irregularly situated simple long setae ( Fig. 67 ). Posterior margin of abdominal tergum I without denticles; posterior margins of terga II–VIII with blunt brown denticles ( Fig. 65 ); posterior margin of tergum XI with blunt, rounded and pointed denticles, without denticles behind pair of submedian pores ( Fig. 66 ); tergum X with pointed denticles ( Fig. 58 ). Posterior margin of abdominal sterna I–IV without denticles; posterior margin of sterna V–VIII with blunt and split denticles ( Fig. 67 ); posterior margin of sternum IX of mature male larva with prominent semicircular smooth protogonostyli and dense stick-like denticles between them ( Fig. 68 ). Paraprocts with pointed denticles on apex and median side ( Fig. 81 ). Lateral denticles either absent, or present only on distal part of abdominal segment IX ( Fig. 57 ) [see Anafroptilum (3)]. Each tergalius I–VII with long costal and anal marginal ribs, without denticles, distal margin without rib; tergalius I asymmetrically widened in distal part; tergalius II asymmetrically widened in midlength; tergalii II–VI asymmetrically widened in proximal part; tergalius VII nearly symmetrical ( Figs 69–75 ). Cerci with small denticles on all segments; one simple or composed larger spine can be present on lateral side of cercus near tip; among two examined individuals, the holotype has double spine on each cercus ( Fig. 55 ); the paratype has single spine on left cercus and vestigial spine on right cercus. Outer side of cercus without additional setae.

Subimago. Cuticular coloration. Head colorless. Pronotum and prosternum light brown. Mesonotum nearly colorless with brown microtrichia, certain sutures light brown ( Fig. 83 ). Thoracic pleura and sterna at most part nearly colorless with brown microtrichia, certain sclerites light brow ( Fig. 84 ). Legs nearly colorless with brown microtrichia. Abdominal terga and sterna nearly colorless with brown microtrichia; terga with very light brownish sublateral markings. Cerci very light brownish with brown spines.

Texture. On all legs all tarsomeres covered by pointed microlepides [see Anafroptilum (7)].

Imago, male ( Fig. 82 ). Turbinate eyes with stem light yellow basally, grayish-white distally; facetted surface light brownish. Thorax light brownish with ocher. Legs pale ocher. In holotype, proportion of femur / tibia / tarsal segments of fore leg 70: 115: 3: 56: 42: 29: 14; middle leg 56: 56: 20: 7: 3: 12; hind leg 56: 50: 17: 6: 3: 12. Tarsus of middle and hind leg with one apical spine on 2nd tarsomere (primary 3rd tarsomere). Fore wing with membrane and veins colorless; pterostigma with 2–3 simple oblique veins. Hind wings absent. Abdomen nearly colorless, VII–X segments pale ocher. Cerci unicolor light ocher.

Unistyligers and gonostyli colorless ( Figs 85 ). Unistyligers nearly meet together by their bases; styligeral muscle wide, attached to bases of unistyligers ( Fig. 79 ). Finger-like sclerotized projection between unistyligers ( Fig. 79, 80 , 85 ). 1st segment of gonostylus with prominent projection on inner side; 2nd segment arched; 3rd segment relatively large ( Figs 79 , 85 ) [see Anafroptilum (15)]. Penis brown; external part of penis wide roundishtriangular, with apical margin smooth.

Female and eggs. Unknown.

Dimension. Fore wing length of male 3.5 mm.

Figures

FIGURE 78. Anafroptilum odontostylus sp. n., labium, ventral view (left) and dorsal view (right). Abbreviation: mr, median row of setae of glossa.

FIGURES 54 – 59. Anafroptilum odontostylus sp. n., larva. 54, eXuviae of abdominal sterna (left) and terga (right); 55, enlarged portion of cercus; 56, eXuviae of left half of pronotum and mesonotum; 57, lateral margin of IX abdominal segment; 58, abdominal tergum X; 59, apeX of femur (54 – 55, 57 – 59, holotype).

FIGURES 60 – 64. Anafroptilum odontostylus sp. n., larva. 60, labrum; 61 – 62, left and right mandibles; 63, mola of left mandible; 64, claw (60, 61, 64, holotype). Abbreviations: al, apical lamella of molar process; dmp, distal molar projection.

FIGURES 65 – 68. Anafroptilum odontostylus sp. n., eXuviae of larval abdomen. 65, median part of tergum III; 66, posterior part of tergum IX; 67, median part of sternum VIII; 68, posterior part of sternum IX of male with protogonostyli. Arrows show pairs of submedian pores; abbreviations: sVIII, sIX, sterna VIII and IX; tIII, tIX, terga III and IX.

FIGURES 69 – 77. Anafroptilum odontostylus sp. n., larvae. 69 – 75, tergalii I – VII; 76, labrum and part of clypeus; 77, maXilla, dorsal view (76, holotype). Abbreviations: c 1, c 2, c 3, maXillary canines; ds 1, ds 2, ds 3, dentisetae.

FIGURES 79 – 81. Anafroptilum odontostylus sp. n. 79, genitals of male imago; 80, gonostyli of male subimago; 81, larval paraproct (79 – 80, holotype). Abbreviations: gs 1, gs 2, gs 3, segments of gonostylus; m. IX-X, areas of anterior attachment of median paraproctal muscles (i. e., muscles going from sternum IX to common base of paraprocts); usg, unistyliger.

FIGURES 82 – 85. Anafroptilum odontostylus sp. n. 82, male imago; 83, right half of eXuviae of subimaginal mesonotum; 84, eXuviae of subimaginal pleuron; 85, genitals of male imago (85, holotype).

FIGURES 37 – 43. Anafroptilum orthostylus sp. n. 37, part of eXuviae of larval head with labrum, bases of antennae and frontal suture; 38 – 39, incisor, kinetodontium and prostheca of left and right mandibles, view from base of mandible; 40, paraproct; 41, genitals of male imago (on the left half, gonovectal muscles and hidden part of penis shown by interrupted lines, gonostylar muscle not shown; at right half gonostylar muscle shown by interrupted lines; median styligeral muscle shown by interrupted lines, areas of anterior attachment of median paraproctal muscles shown by dotted lines); 42, eXuviae of gonostyli of subimago; 43, larval protogonostyli and subimaginal gonostyli developing under larval cuticle (40, 42, holotype). Abbreviations: gs 1, gs 2, gs 3, segments of gonostylus; in, incisor; kd, kinetodontoum; m. IX-X, areas of anterior attachment of median paraproctal muscles (i. e., muscles going from sternum IX to common base of paraprocts); prs, prostheca; usg, unistyliger.