Oecetis barisan, Oláh & Johanson, 2010

Oláh, János & Johanson, Kjell Arne, 2010, Fifteen new Trichoptera (Insecta) species from Sumatra, Indonesia, Zootaxa 2618 (1), pp. 1-35 : 26-28

Oecetis barisan , new species

Figs 53–56

This species is similar to O. chrysaor Malicky from Indonesia (Sumatra) and Malaysia (Pahang). Oecetis barisan is distinguished from O. chrysaor by having undivided reticulation on terga VI, VII and VIII; gonopods with a different shape in lateral view (without the long, vertically directed basodorsal lobe); and a phallic apparatus with a single spine.

Male. Body brown; eyes black. Scapes robust, almost as long as head, without elongated setal tufts; filling depressions of enlarged sockets on head dorsum. Maxillary palp formula IV-(I,III,V)-II. Anterior surface of head (or cephalic face) with narrow frontal area and enlarged genal area; wide frontogenal areas occupied by large frontogenal compact setose warts. Clypeogenal compact setose warts small, rounded, located above articulations of each first maxillary palp segment. Labrum elongated axially, posterior part covered with diffuse setal wart. Haustellum narrow at base, broad at mid-length, with mesodistal hump; posterior half covered with parallel channels. Head dorsum with large, inverted V-shaped vertexal medioantennal compact setose wart dominating on head dorsum between and behind scapes; postgenal compact setose warts small, attached to ocular groove ventrally, forming narrow wart invisible in dorsal view. Two pairs of setose warts present on head dorsum: large, nearly quadrangular, compact, occipital setose warts, slightly elongated axially and slightly narrowing anteriorly; rounded vertexal ocellar compact setose warts. Coronal, lateral vertexal, occipital and postoccipital grooves forming dark brown lines on head dorsum. Cranial areas and warts medium brown. Swollen proepisternal setal warts absent. Katepisternum of mesopleuron acute anterodorsally. Abdominal terga VI, VII and VIII with large, undivided reticulation; terga VI and VII darker than tergum VIII.

Spur formula 0,2,2; middle legs each with anteroapical spur 3 times longer than posteroapical spur; hind legs each with anteroapical spur half as long as posteroapical spur; middle leg apical spurs each smaller than hind leg apical spurs.

Forewings brown with dark brown pattern, length 4.9 mm.

Male genitalia. Segment IX triangular to nearly drop-shaped in lateral view; acutely short dorsally; tergum very short, partly covered by tergum VIII. Segment X fused with tergum IX; almost membranous, forming single, median mace-shaped clavate process. Paraproctal complex forming pair of dorsolateral guiding structures for phallic apparatus; fused basally to area near tergum IX and venter of segment X, forming glabrous, elongated blades, each with single, terminal seta or bristle. Cerci setose, elongate, clubshaped in lateral view. Gonopods short, with 2 basal and 2 terminal processes in lateral view. Phallic apparatus with phallobase divided posteriorly into dorsal and ventral lobes; dorsal lobe deeply incised in dorsal view. Endotheca basally membranous, amorphous, continuing into ventral, asymmetric, sclerotized, rod-shaped phallicata and dorsal membrane with pair of phallotremal sclerites and single paramere spine originating from membranous pad.

Holotype male: INDONESIA (Sumatra): Bukit Barisan Selatan National Park, Barisan Mts., Way Pitias , 800 m, 17–19.vi.2008, light trap [J. Oláh, Jr.]— 1 male (OPC, in alcohol).

Distribution: Indonesia (Sumatra).

Etymology: Barisan, named after the type locality.

Remark: This species belongs to the Oecetis testacea species group.

Figures

FIGURES 53–56. Oecetis barisan, new species, holotype. 53—genitalia, left lateral; 54—genitalia, dorsal; 55—right gonocoxite, ventral; 56—phallic apparatus, left lateral.