Caltoris bromus bromus (Leech, 1894)

KC, Sajan, Pariyar, Surendra & Sapkota, Anisha, 2025, Refining Nepal's butterfly records: self-corrections and notes on previously recorded Papilionoidea (Lepidoptera) species, Journal of Insect Biodiversity and Systematics 11 (2), pp. 363-377 : 365-367

Caltoris bromus bromus (Leech, 1894)

Parnara bromus Leech, 1894 , Type locality: Chia-kou-ho, China.

Material Examined. 3 ♂♂, NEPAL, AFU, Rampur, Chitwan District , Bagmati Province (27°39'19.5"N 84°21'12.5"E, 162 m), 27-IX-2021 ; 3 ♀♀, same data label, Coll. Sajan KC .

Diagnosis. Caltoris b. bromus can be distinguished from its sympatric congeners by, in females, usually distinctive twin spots on the ventral side of the hindwing in spaces 2 and 3 ( Fig. 2A, but see Fig. 2B (male)), and the presence of well-developed spots, including cell spots, on the dorsal side of the forewing ( Figs 2C, 2E) ( Evans, 1949; Fleming, 1975).

Remarks. Reported as a new record for Nepal by the first author in KC (2022), C. b. bromus was frequently observed (at least 30 times) at the given location between 2019 and 2021. Notably, its occurrence in Nepal is highly localized, with no sightings recorded from elsewhere in the country. The first sighting occurred on June 25, 2019 ( Fig. 2A), followed by multiple individuals observed in the same location during 2020–2021 in August and September, respectively.

The surrounding vegetation comprised various grass species ( Poaceae ), Mangifera indica L. ( Anacardiaceae ), Lantana camara L. ( Verbenaceae ), Ziziphus Mill. sp. ( Rhamnaceae ), and numerous weeds.

Interestingly, while Evans (1949) noted that only females of C. b. bromus sometimes possess double spots on the ventral hindwing, all individuals observed in this study, including males, exhibited such spots ( Figs 2A, 2B, 2D, 2F), which is consistent with the specimens shown by Inayoshi (2024). Evans (1949), Zhang et al. (2010), and Inayoshi (2024) were referred to for genitalia analysis ( Figs 2G–2K), which revealed lamella postvaginalis with smooth lamella and rounded shoulders in females, longer than the lamella itself ( Fig. 2G). In males, the analysis showed much longer dorsal process of the valva compared to the distal process (cuiller sensu Evans, 1949) ( Figs 2H, 2I). Previously, the species was recorded from as close as Assam ( Van Gasse, 2018), approximately 830 km east of the study area (https://earth.google.com/web). Its occurrence in AFU, Rampur, Chitwan District, could be attributed to accidental introduction through the transportation of grasses, its larval host plant(s), in recent years, given the study area’s proximity to a grass research center. Alternatively, areas between Assam and Chitwan may have been under-sampled, leading to an incomplete understanding of its distribution.

Distribution. China, Hong Kong, Myanmar, Malaysia, Indonesia ( Evans, 1949); NE India ( Varshney & Smetacek, 2015); Laos, Thailand, Vietnam ( Inayoshi, 2024); Nepal (New Record).