A study of morphometric traits and length-length relationships of the butterfly, Melanitis phedima (Lepidoptera: Nymphalidae)

Abstract

The present study deals with the investigation of the morphometric traits including morphometric lengths and length-length relationships (LLRs) of the dark evening brown butterfly, Melanitis phedima (Lepidoptera: Nymphalidae). Butterflies were sampled randomly from the Rajshahi University campus, Bangladesh. The pictures of butterflies were taken with a DSLR camera (Canon 750D), and a total of 14 different morphometric lengths from the body, antenna, wings (6 parameters), legs (2 parameters) and wing venation (4 parameters) were measured using ImageJ software (1.52a). The minimum and maximum body length (BL) were recorded at 19.15 mm and 24.85 mm from M. phedima respectively, whereas the mean body length was 22.02±1.45 mm. This study found FL (Foreleg) as the short trait at 12.90 mm, while FWBA (Forewing Base-Apex) was the long trait at 45.86 mm. The length of FWBA was 88.75% longer than BL and HWAT (Hindwing Apex-Tornus) was 40.25% longer. On the other hand, lengths of antennae length (AL), total foreleg (TFL) and total hindleg (THL) were shorter compared to BL. According to the coefficient of determination (r 2 ), all values were  0.75 which indicates the positive relationship between BL and selected 13 traits and the best-fitted model of LLRs was BL vs. HWBA (Hindwing Base-Apex) among these equations (r 2 = 0.89). The allometric coefficient 'b' indicated the isometric growth for BL vs. HWBT and BL vs. HWAT, and negative allometric growth for BL vs. FWBA (b < 1), and the rest 10 traits showed positive allometric growth (b > 1). The results would be very effective for the study of butterfly taxonomy as a great tool in species and subspecies identification.

Length-Based Morphometric Study of the Morphologically Resembling Butterfly Species Within the Genus Graphium (Lepidoptera: Papilionidae)

“…Based on the current findings, Graphium species were observed to have bigger wingspans ranging from 60.4 to 70.2 mm, as compared to the butterflies from the genus Eurema that ranged from 35.3 to 43.9 mm (Azrizal-Wahid et al, 2016), and genus Melanitis (mean = 25.26, SD = ±1.22 mm) (Mahdi et al, 2022). Having a large wingspan is concordant with the preferable area of Graphium that is likely to inhabit high-elevation areas.…”

“…Due to a need for more literature data on morphometrics of the genus Graphium, restrains us from comparing our results with other findings. Nevertheless, reasonable comparison still be made based on several similar studies done on other species or groups of butterflies, for example, family Lycaenidae (Akand et al, 2017;Mahdi et al, 2021), Pieridae (Azrizal-Wahid et al, 2016), Hesperidae (Zerganipour et al, 2021), and Nymphalidae (Mahdi et al, 2022).…”