Ogcogaster Westwood, 1847

Hassan, Muhammad Asghar & Liu, Xingyue, 2021, Taxonomic notes on owlflies from Pakistan (Neuroptera: Myrmeleontidae Ascalaphinae), Zootaxa 4970 (3), pp. 401-452 : 426-427

Genus Ogcogaster Westwood, 1847

Ogcogaster Westwood, 1847: 69 . Type species: Ascalaphus (Ogcogaster) tessellatus Westwood, 1847: 69 . Subsequent designation.

Horischema Mészáros & Ábrahám, 2003: 341 . Type species: Horischema ronkayorum Mészáros & Ábrahám, 2003: 341 . Monotypy. syn. nov.

Perissoschema Mészáros & Ábrahám, 2003: 343 . Type species: Perissoschema evae Mészáros & Ábrahám, 2003: 346 . Monotypy. syn. nov.

Diagnosis. Ogcogaster can be easily distinguished by its long and cylindrical male ectoprocts, which extend downward with a rounded apex in lateral view, and which are covered with short black setae ( Figs 18C–D ; Mészáros & Ábrahám 2003: figs 3, 7). The coloration of wing membranes is highly variable, hyaline to dark brown, as is common in Ascalaphinae . The genus is also characterized by the narrow brownish marking just below the pterostigma, forming a V-shape in both wings or by the distinct dark brown speckles of crossveins along the costal area, between R and M and the apical area beyond Sc+R with two rows of cells.

Remarks. Two monotypic genera, i.e., Horischema and Perissoschema , were described by Mészáros & Ábrahám (2003) from Pakistan with H. ronkayorum Mészáros & Ábrahám (2003) and P. evae Mészáros & Ábrahám (2003) as type species, respectively. The former species was considered restricted to the northeastern part of Pakistan, and the later species was distributed from the northeastern part of Pakistan to Nepal Himalayas. The diagnostic characters used by the authors to define Horischema include the relatively larger body size (forewing length: 31.0–32.0 mm) and robustness of the body, and for Perissoschema the speckled wings with bright ochre-yellow pterostigma. The two genera were originally described as closely related to the species of Deleproctophylla and Puer by Mészáros & Ábrahám (2003) due to similarities in external morphology and male genitalia. However, the similarities are even greater when Horischema and Perissoschema are compared to Ogcogaster . The diagnostic characters and description of Perissoschema evae Mészáros & Ábrahám (2003) easily fit with that of Ogcogaster segmentator Westwood, 1847 , and the two species are quite similar in wing coloration and external morphology as determined by photographs of the type species in Tauber et al (2019: figs 20–22). Hence, we consider the earlier described monotypic genera, Horischema and Perissoschema , as junior synonyms of Ogcogaster and regard Perissoschema evae as the junior synonym of Ogcogaster segmentator .

The genus Ogcogaster is currently represented by six species which are restricted to India (4 species), Pakistan (3 spp.) and Nepal (1 sp.). Until now, only three species of Ogcogaster were known from Pakistan. The taxonomic history of Ogcogaster tessellata was initially associated with Westwood (1847), who placed it under the genus Ascalaphus within the new subgenus Ogcogaster . Later, Hagen (1866) elevated the subgenus to generic status. Until now, the species is only known from Pakistan and India. It is mentioned in the checklists of Indian Neuroptera ( Ghosh & Sen 1977; Ghosh 1988, 2000), annotated checklist of Ascalaphidae of Asia and the Pacific Islands ( Sziráki 1998) and in the catalogue of Neuropteridae from Pakistan ( Hassan et al. 2019). Most recently, Tauber et al. (2019) provided the first detail photographs of the dorsal habitus of three females, showing variability in color patterns and wing markings. According to the label information, these specimens, which are housed at the Oxford University Museum of Natural History (OUMNH), United Kingdom, are from India. We re-described the species based on our recent materials, particularly that collected from the northern parts of Pakistan, exhibiting the similar variability of color patterns and wing markings ( Figs 14A–C , 15A–D ). The variation may be due to different stages of maturity or ecological factors.

Key to Ogcogaster species from Pakistan

1. Pterostigma bright ochre-yellow, without brownish marking on proximal to Sc+R vein; crossveins with distinct dark brown speckles along the costal area, presectoral area, proximal 1/4 of mediocubital area and first row of crossveins between R and Rs in both wings; Sc and R yellow ( Mészáros & Ábrahám 2003: figs 5–6; Tauber et al. 2019: figs 20–22).............................................................................................. O. segmentator Westwood

_. Pterostigma dark brown, with a narrow brownish marking on proximal to Sc+R vein, thus forming a V-shaped; wing membrane hyaline or dark brown, with or whithout brownish speckle along the proximal half of both wings; Sc and R brownish yellow.. ................................................................................................... 2

2. Wing membrane hyaline, except brownish projection of pterostigma in both wings ( Mészáros & Ábrahám 2003: figs 1–2)...................................................................... O. ronkayorum (Mészáros & Ábrahám)

_. Wing membrane dark brown or hyaline with proximal half of both wings with indistinct brownish speckles along crossveins in females; proximal to the hind margin on mediocubital area in both wings with distinct brownish markings ( Figs 14A–C )..................................................................................... O. tessellata (Westwood)

Figures

FIGURE 14. Ogcogaster tessellata (Westwood). Male. A–C. Dorsal habitus. Scale bar: 5.0 mm.

FIGURE 15. Ogcogaster tessellata (Westwood). Female. A–D. Dorsal habitus. Scale bar: 5.0 mm.

FIGURE 18. Ogcogaster tessellata (Westwood). A. Female genitalia, lateral view; B. Same, ventral view; C. Male genitalia, lateral view; D. Same, ventral view; E–G. Gonarcus, parameres and pulvinus: E. Dorsal view; F. Same, ventral view; G. Same, lateral view. Scale bar: 0.5 mm.