Indocloeon (Hindocloeon), 2020

Kluge, Nikita J. & Suttinun, Chanaporn, 2020, Review of the Oriental genus Indocloeon Müller-Liebenau 1982 (Ephemeroptera: Baetidae) with descriptions of two new species, Zootaxa 4779 (4), pp. 451-484 : 482

Indocloeon (Hindocloeon) sp. « Vietnam »

( Fig. 103 )

Material examined ( ZIN). VIETNAM, 40 km W Nha Trang, left tributary of river Ben Loi near Ju Hoai, N12º14’01”, E108º47’12” h= 295m, 15.VII.2018, coll. V. Ivanov: 8 S ♂, 7 S ♀ .

Descriptions. Subimaginal cuticular colouration. Most part of cuticle colourless, lateral sclerite of parascutellum and posterior part of postsubalar sclerite brown.

Male subimago. Turbinate eyes red. Antenna: distal part of scapus with hypodermal pigmented spots on lateral and median sides; distal part of pedicellus with hypodermal pigmented spots on lateral and median sides (as in Fig. 92 ) [see Hindocloeon (9)]. Other hypodermal colouration either entirely absent, or first abdominal segment with pair of brown spots just ventrad of metathoracic postnotum (as in Fig. 92 ) [see Hindocloeon (10)]. Lateral trachea of abdomen contrastingly pigmented with blackish. Subimaginal gonostyli moderately wide at base ( Fig. 103 ).

Female subimago. Antennae as in male (see above). Other hypodermal colouration entirely absent. Lateral trachea of abdomen contrastingly pigmented with blackish.

Dimension. Fore wing length (and approximate body length) 3.3 mm.

Comments. Male subimagines are determined as belonging to Indocloeon s. l. based on the peculiar structure of the gonostyli ( Fig. 103 ). Female subimagines are determined as belonging to the same species based on the having equally colourless cuticle and the same structure of middle and hind legs of males. Belonging of the female subimagines to Indocloeon s. l. is proven by the absence of the patella-tibial suture on the fore legs. This species differs from I. (H.) longistylus by having a relatively longer proximal segment of the gonostylus, even in the subimaginal stage. Male and female subimagines differ from the subgenus Indocloeon s. str. by the absence of reddish stripes on the posterior margins of abdominal terga. Males differ from I. (H.) indonesiae and I. (H.) continentale sp. n. by the absence of brown pigmentation on abdominal terga VIII–IX. The female subimago differs from I. (H.) indonesiae , I. (H.) continentale and I. (H.) sp. « Java » by the absence of brown maculae on abdominal terga and sterna.

Figures

FIGURES 101–105. Male genitals of Hindocloeon. 101, imaginal genitals of Indocloeon (Hindocloeon) continentale sp. n. (penis dotted; 1+2, proximal segment of gonostylus; 3, distal segment of gonostylus; gv-d, distal portion of gonovectis; gv-p, proximal portion of gonovectis; m.d, dorsal muscle of penis; m.gs, gonostylar muscle; m.gv, gonovectal muscle; m.s., median sterno-styligeral muscle); 102, their subimaginal exuviae; 103, subimaginal gonostyli of I. (H.) sp. «Vietnam»; 104, subimaginal gonostyli of I. (H.) sp. «Java»; 105, imaginal genitals of I. longistylus (after Demoulin 1969).

FIGURES 91–95. Indocloeon (Hindocloeon) continentale sp. n. 91, fragment of subimaginal exuviae with postsubalar sclerite; 92, antennae of male imago; 93, male imago; 94, its metathorax and base of abdomen; 95, male subimago (arrow shows brown hypodermal spot just ventrad of metathoracic postnotum).