Horniolus darjeelingensis, Poorani, 2022

Poorani, J., 2022, A review of Horniolus Weise (Coleoptera: Coccinellidae) from the Indian region, including descriptions of two new species, Zootaxa 5104 (4), pp. 545-556 : 550

Horniolus darjeelingensis sp. n.

( Fig. 3 )

Diagnosis. This species can be differentiated from the other known species of Horniolus by its much larger size (2.80 mm long), more robust, broadly oval outline and the colour pattern with reddish brown head and pronotum and yellowish brown, medially infuscate elytra with a pair of basal maculae and a pair of median black spots and the male genitalia. It superficially resembles H. sonduongensis Hoàng, 1979 (as illustrated by Szawaryn & Větrovec 2020) in terms of elytral pattern but the latter appears to be a much darker species with different male genitalia. The male genitalia in H. darjeelingensis sp. n. also somewhat resemble those of H. vietnamicus but the penis guide in the former has distinct lamellate expansions (absent in H. vietnamicus ) and is apically broader and less acutely curved in lateral view (apically narrowed and acutely pointed in H. vietnamicus ).

Description. Holotype male: Length: 2.80 mm; width: 1.81 mm; PL: 0.97 mm; PW: 1.29 mm; EL: 1.84 mm; EW: 1.81 mm. Form ( Fig. 3a ) broad oval, dorsum convex with dense yellowish white pubescence, eyes with erect silvery white hairs. Head and pronotum reddish brown with dark brown lateral margins, scutellar shield medially reddish brown with dark brown borders, elytra yellow, sutural and adjoining areas reddish brown, basal margin of elytra with a black median fascia with an emarginate lower margin, not reaching scutellar shield / lateral or humeral area; middle of each elytron with a black transverse spot (outer half narrow, inner half distinctly broader); margins of elytra narrowly black to dark brown; ventral side yellowish-testaceous, antenna and legs yellow. Head nearly 5x as wide as an eye, frons broad, interocular distance slightly more than thrice as wide as eye. Pronotum densely punctate on disc, punctures separated by 1–3 diameters, very shallowly impressed, interspaces between punctures shiny, punctures distinctly larger and more closely spaced and denser on lateral and anterolateral areas. Elytral punctures densely punctate, shallowly impressed, separated by 2–4 diameters, interspaces shiny. Abdominal postcoxal lines ( Fig. 3b, c ) complete, deeply semicircular, enclosed area with punctures progressively larger towards posterior. Male genitalia as illustrated ( Figs. 3d–g ), penis guide in ventral view ( Fig. 3d ) parallel-sided for up to two-thirds of its length, abruptly narrowed and triangular in the apical third, shorter than parameres, parameres with dense, elongate lateral and apical setae ( Fig. 3e ); penis ( Fig. 3f ) with a well-developed capsule having a short outer process and a distinctly longer inner process, apically modified as illustrated ( Fig. 3g ).

Female: Not studied.

Material examined. Holotype male: “ India W. Bengal, Darjeeling dist. , Singla 300m 17.x.78, Besuchet Löbl” ( NBAIR).

Distribution. India: West Bengal (Darjeeling).

Etymology. The specific epithet is in reference to its type locality (Darjeeling).

Figures

FIGURE 3. Horniolus darjeelingensis sp. n.: a. holotype male, dorsal view; b. abdomen; c. abdominal postcoxal line; d–g. male genitalia: d. tegmen, ventral view; e. tegmen, lateral view; f. penis; g. penis apex.