Choroterpes (Dilatognathus) cataractae Kluge 2012

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) cataractae Kluge 2012

(Figs 1–15, 30, 32, 36, 37)

Material (holotype and paratypes). INDONESIA, LOMBOK, Senaru, under Sendang Gila waterfall, 19– 26.IX.2009, coll. N. Kluge & L. Sheyko: 4 L-S-I♂, 10 L-S-I♀, 1 L-S♂, 1 L-S♀, 52 larvae and larval exuviae: 12 L n♂, 22 L n♀, 1 L n- 1♂ (at molting to L n), 11 L n-1♀, 1 L n- 2♂, 4 L n-2♀, 1 L n-3♀.

Additional characteristics. Larva, subimago, imago and eggs are described by Kluge (2012). Apex of penis, hypodermal coloration of abdomen and legs and denticles on posterior margin of larval terga are figured here (Figs 1, 30, 32).

Structure of maxillary apex in penultimolarva and previous larval instars differs in males and females (Figs 6– 13). In pen-pen-penultimolarva (L n-3) ventro-apical flange and dentiseta are present, and tusk is not expressed (Fig. 13); this structure is observed on a single female larva, and probably is equal in both sexes. In male, larva of next two instars (L n-2 and L n-1) gets a short tusk and retains ventro-apical flange and dentiseta (Figs 7, 8) (this was observed on one larva of each instar).When male larva molts from penultimolarva (L n-1) to ultimolarva (L n), its maxillary structure is greatly changed ( Fig. 14 ). In female, such change takes place earlier. In female penpenultimolarva (L n-2) maxilla has a long tusk and diminished ventro-apical flange; dentiseta is present (Fig. 12), but can be vestigial and nearly indistinguishable among setae (Fig. 11). In female penultimolarva (L n-1) maxilla has no ventro-apical flange and no dentiseta (Fig. 10); it is similar to maxilla of ultimolarva, but shorter ( Fig. 15 ).

Dimension. Fore wing length 7.5– 8 mm.

Distribution. Lombok Island.

Habitat. All larvae were collected in a single place, under Sendang Gila waterfall. We did not find larvae of this species in other parts of the same river.

Figures

FIGURES 14 – 15. Choroterpes (Dilatognathus) cataractae, maxilla of penultimolarva before molt to ultimolarva (slides in Canadian balsam): 14, male; 15, female. Abbreviations: af, ventro-apical flange; ds, dentiseta.