Choroterpes (Dilatognathus) bogori, Kluge, Nikita J., 2014

Kluge, Nikita J., 2014, Indonesian species of Dilatognathus Kluge 2012 (Ephemeroptera, Leptophlebiidae, Choroterpes s. l.) and species-specific sexual dimorphism in development of maxilla, Zootaxa 3786 (1) : -

Choroterpes (Dilatognathus) bogori sp.n.

( Figs 16–24 , 29, 31 , 34, 35, 38, 39–43 )

= " Choroterpides exiguus " sensu Ulmer 1939 (non Thraulus exiguus Eaton 1884 ); = Dilatognathus/g(1) sp.2: Kluge 2012.

Material. Holotype: L-S-I♂ {No. [XXIII] (5)}, INDONESIA, JAVA, Bogor, river Ci Sadane, 3.IX.2012, coll. N. Kluge. Paratypes: the same locality and date: 4 L-S-I♂, 1 L-S♂, 4 L-S-I♀, 98 larvae: 20 L n♂, 38 L n♀, 9 L n- 1♂, 20 L n-1♀, 4 L n- 2♂, 5 L n-2♀, 1 L n- 3♂, 1 L n-3♀; river Ci Liwung in botanic garden of Bogor, 2.IX.2012: 1 L-S-I♂, 19 larvae: 5 L n♂, 9 L n♀, 1 L n- 1♂, 2 L n-1♀, 2 L n-2♀; the same locality, 24.II.2008, at light, coll. V. Ivanov: 2 I ♂, 4 S♂, 1 S♀.

Descriptions. Larva. CUTICULAR COLORATION: Cuticle of head, pronotum and mesonotum brown, with diffusive markings; cuticle of legs and abdomen light brownish, nearly unicolorous, without contrasting markings.

HYPODERMAL COLORATION: General color light brown. Head and thorax with dark maculae. Legs light ocher; each femur with large brown macula or band at middle, sometimes with smaller brown macula at apex, which is separated from middle macula (as in imago, Fig. 31 ). Abdominal terga with brown pigmentation, median-anterior part of each tergum ocher (as in imago, Fig. 29 ). Dorsal lamella of each tergalius light brown, with main trachea bordered by dark brown and side tracheae poorly visible; ventral lamella lighter brownish, with lighter trachea.

SHAPE AND SETATION: Labrum as in Ch. (D.) cataractae ( Kluge 2012: Fig. 133): median incision very shallow, with shallow convexity in middle and 5 shallow denticles ventrad of it ( Fig. 24 ); proximal transverse row of setae (shifted proximally, as in all Dilatognathus) interrupted medially; instead of distal transverse row, there is a wide stripe of irregularly situated setae, smaller than setae of the proximal transverse row; most part of dorsal surface with irregularly situated long and thin setae, somewhat smaller than setae of the distal stripe. Maxilla without dentiseta at least beginning from instar L n-3; with maxillary tusk at least beginning from instar L n-3; without ventro-apical flange beginning from instar L n-2. In both sexes maxilla of pen-pen-penultimolarva (L n-3) with wellexpressed maxillary tusk; ventro-apical flange either small ( Fig. 20 ) or smoothed out ( Fig. 19 ). In next instars (from L n-2 to L n) ventro-apical flange not expressed, and maxillary tusk becomes progressively longer at each instar ( Fig. 18 ). Three vestiges of pectinate setae present in all instars. Legs as in Ch. (D.) cataractae ( Kluge 2012: Figs 147–151): Femur of fore leg widest proximally, femora of middle and hind legs widest at middle. Femora with irregularly situated stout setae of various lengths; dorsal side of fore femur with few setae, dorsal side of middle and hind femora with many setae. Ventral side of hind femur with irregular row of curved bipectinate setae. Stout pointed bipectinate setae on inner side of fore tibia situated densely and irregularly. Inner side of middle and hind tibia with sparse row of stout setae; dorsal side of middle tibia with row of longer setae; outer side of hind tibia with stout setae of variable length, as on outer side of femur. Outer sides of all tibiae with irregularly situated thin hairs, whose length exceed tibia width. Abdominal segments VIII and IX with posterolateral spines short and obtuse. In all instars including ultimolarva, hind margins of abdominal terga I–II without regular row of denticles ( Fig. 34 ); terga III–VII with row of very small, thin, spine-like denticles only in middle part ( Fig. 35 ); terga VIII–X with row of somewhat longer denticles; sterna lack denticles. Tergalii II–VII with apical processes gradually narrowed toward apex ( Fig. 23 ); tergalii II–V of equal size and shape, tergalius VI smaller, tergalius VII smallest and lacks costal process of dorsal lamella; anal-proximal projection of ventral lamella poorly expressed on tergalius II, better developed on tergalii III–VII. Protogonostyli of male larva short and narrowly separated; protopenes convergent, completely hidden under sternum XI; female larva has hind margin of abdominal sternum IX slightly incised [as in Ch. (D.) cataractae ] ( Kluge 2012: Figs 143, 144).

Subimago. CUTICULAR COLORATION: Cuticle of thorax at most light with brown sclerites; mesonotum at most brown; most part of medioscutum and submedioscutum brown, posterior scutal protuberance brown ( Fig. 38 ). Cuticle of legs light, with diffusive brownish longitudinal stripes. Wings light brownish. Cuticle of all abdominal terga and sterna colorless; cuticle of gonostyli light brownish.

HYPODERMAL COLORATION: Abdomen and femora with brown coloration as in imago.

TEXTURE: On each leg 1st tarsomere (shortened and fused with tibia) covered by microtrichiae of the same shape as microtrichiae on tibia; 2nd–5th tarsomeres covered by pointed microlepides.

Imago, male. Head light brown with ocher; dorsal eyes not elevated, brownish-orange. Thorax light brown with ocher. Fore and hind wings with membrane nearly colorless, evenly tinged with light ocher; veins from light brown to colorless; pterostigma with 9–15 simple cross veins. Hind wing with blunt costal projection. Femora of all legs light ocher-brown with contrasting dark brown band in middle ( Fig. 31 ). On fore leg tibia and tarsus entirely light brown. On middle and hind leg tibia lighter, with brown base ( Fig. 31 ). Abdominal terga II–VII in anterior-median part light ocher, in posterior and lateral parts brown with ocher blanks ( Fig. 29 ). Abdominal sterna I–VIII light. Abdominal sternum IX and styliger ocher with brown, gonostyli light brown. Styliger with nearly straight posterior margin. 1st+2nd segments of gonostylus with inner margin angulated. Penis lobes apically pressed together; each lobe with apical projection moderately long, conic, slightly bent medially-dorsally, rounded apically; denticles absent, instead of them few round concavities on dorsal side of penis close to apex ( Fig. 21 ). Caudalii light brown, with dark brown ring at each joining.

Imago, female. Coloration as in male. Posterior plate of abdominal sternum IX apically slightly incised.

Egg. Oval, 0.15 mm length. Chorion with evenly dispersed papillae and ridges going from one papilla to another; papillae small, on one pole larger ( Fig. 39–43 ).

Dimension. Size of both sexes greatly varies: fore wing length 5–8 mm.

Distribution. Java.

Habitat. Larvae were collected in rivers Ci Sadane and Ci Liwung at places with stony bottom and fast current. This species is most abundant upstream of the city, where water pollution is moderate; but is also present in center of Bogor (Ci Liwung in botanic garden), where the river is extremely polluted. In this respect, Ch. (D.) bogori markedly differs from Ch. (D.) cataractae and Ch. (D.) major , whose larvae were found only in selected areas of clean rivers under certain waterfalls.

Diagnosis. Male and female imagoes differ from Ch. (D.) cataractae by absence of brown coloration in proximal part of subcostal field of fore wing. Larva of penultimate and previous instars differs from Ch. (D.) cataractae by structure of maxilla (compare Figs 19, 20 and 6–13): pen-pen-penultimolarva of both sexes differs by presence of maxillary tusk and absence of dentiseta; pen-penultimolarva of both sexes differs by absence of dentiseta and ventro-apical flange; male penultimolarva differs by absence of dentiseta and ventro-apical flange. Imagoes, subimagoes and larvae differ from Ch. (D.) major by light femora with well-expressed dark band at middle (compare Figs 31 and 33 ). Imagoes, subimagoes and larvae differ from Ch. (D.) major and Ch. (D.) cataractae by light median part of abdominal terga (compare Figs 29 and 30 ). Larva of last instar differs from Ch. (D.) cataractae and Ch. (D.) major by absence of regular row of spines on posterior margins of abdominal terga I and II and by smaller spines on abdominal terga III–IX (compare Figs 34–35 and 36–37 ). Larva differs from Ch. (D.) nigella in shape of labrum, and from Ch. (D.) minor in shape of tergalii. Structure of egg ( Fig. 39 ) is the same as in Ch. (D.) cataractae and differs from Ch. (D.) nigella , whose papillae have equal size on all egg surface ( Kang & Yang 1994: Fig. 12); eggs of other species are unknown.

Figures

FIGURES 16 – 18. Choroterpes (Dilatognathus) bogori, maxilla of penultimolarva at various stages of transformation preceding molt to ultimolarva (slides in Canadian balsam): 16, female, early stage; 17, female, middle stage; 18, male, late stage.

FIGURES 19 – 28. Choroterpes (Dilatognathus) spp. 19 – 24, Ch. (D.) bogori: 19 and 20, apex of maxilla in pen-penpenultimate larval instar (ventral view; tusk, ventro-apical flange and vestiges of pectinate ventral setae are shown, other setae not shown): 19, male; 20, female; 21 and 21, genitals of male imago, ventral view (holotype); 23, tergalius III (second existent); 24, middle part of anterior margin of labrum, ventral view. 25 – 26, genitals and enlarged penis of Choroterpides exiguus (Eaton 1884 [Thraulus]) (from Eaton 1884: Pl. 13, Fig. 20 * 2). 27, Choroterpes (Dilatognathus) major, tergalius III (second existent). 28, Choroterpes (Dilatognathus) minor, the same.

FIGURES 29 – 33. Choroterpes (Dilatognathus) spp. 29, Ch. (D.) bogori, abdomen of male imago, spread on slide (holotype); 30, Ch. (D.) cataractae, the same (holotype); 31, Ch. (D.) bogori, hind leg of male imago (holotype); 32, Ch. (D.) cataractae, the same (holotype); 33, Ch. (D.) major, hind leg of mature larva with developing subimaginal leg.

FIGURES 34 – 39. Choroterpes (Dilatognathus) spp. 34 – 37, median part of postrior margin of abdominal tergum of ultimolarva: 34 – 35, Ch. (D.) bogori; 36 – 37, Ch. (D.) cataractae; 34 and 36, tergum II; 35 and 37, tergum VII. 38 – 39, Ch. (D.) bogori: 38, exuviae of right half of subimaginal mesonotum; 39, egg.

FIGURES 40 – 43. Choroterpes (Dilatognathus) bogori sp. n., eggs. 40, 41, total view; 42, 43, two poles of egg in Fig. 41.