The Common Sailor Butterfly, scientifically known as Neptis hylas, is a species of nymphalid butterfly mainly found in South Asia, including Nepal.
Habitat of Common Sailor Butterfly
It is found in a wide range of altitudes, from sea level to 1,000 meters. However, it is most common in lowland areas, and its numbers tend to decline with increasing altitude. In general, the common sailor butterfly prefers open, sunny habitats, such as forests, grasslands, and wetlands.
Flight Behaviour and Pattern of Common Sailor Butterfly
It has a characteristic sailing flight and is active during most of the day except early morning and late afternoon. It eludes the heat by resting in a closed wing position during the hot hours of the day, for otherwise it is found with open wings. It feeds on both flowers and fruits. It is a fast but weak flying butterfly, often seen resting on leaves or branches, and often soars high in the air, searching for food and mates. The common sailor butterfly is a valuable pollinator, and it helps to keep ecosystems healthy.
Features and Behaviour: Male and Female Common Sailor Butterfly
Both the sexes look similar but the female is somewhat larger. The upper side is blackish brown, depending on the sexes, with males having black with white markings and females having brown with white markings. A white streak commencing from the base of the forewing is followed by two white spots which form a band. The background of its underside is golden brown, with the white patches seen on the upper surface visible with additional faint lines in between.
Neptis Hylas, the average sailor, has some characteristics of dual morphism but they are not very different. During the wet season, the white markings on the underside are narrower and the ground color is slightly darker. Also, the black margins are broader on the spots and bands on the underside.
Life Cycle of Common Sailor Butterfly
The life cycle of the common sailor butterfly starts with the female Common Sailor carefully selecting a suitable leaf on the host plant to lay a single egg at the leaf's tip. Using its abdomen, the female reverse along the leaf surface until it reaches the tip, where the egg is then deposited. Each egg is slightly rounded and has hexagonal pits on its surface. It takes around 3 to 3.5 days for the egg to hatch.
After the egg is hatched, the young caterpillar emerges by nibbling a part of the eggshell and consumes the remaining shell as its first meal. The caterpillar is green and has black stripes. It grows for about 2-3 weeks, and it sheds its skin 5-6 times during this time. Its head capsule varies in color from brown to pale brown and is dotted.
During its last larval stage, which takes around 4-6 days, the caterpillar grows up to 25mm in length. Its body color fades to a whitish shade with pinkish tones. Once it stops eating, the caterpillar roams around until it finds a leaf's underside to spin a silk cocoon where it hangs vertically to enter the pre-pupation stage.
Around a day later, the caterpillar turns into a pupa with a relatively short body and slightly expanded wing cases. About 5-6 days further after, the pupa turns dark, developing the white markings on the forewing uppersides visible through the pupal case. The following day, the adult butterfly emerges from its pupal case. The adult butterfly lives for about 2-3 weeks.
Distribution and Spotting of Common Sailor Butterfly in Nepal
The common sailor butterfly can be easily spotted in Nepal, thriving in forests, grasslands, and wetlands. This species can be found all over Nepal excluding high-altitude regions. However, the Terai region is where this butterfly is most commonly observed. The active period of this beautiful butterfly spans from March until November.
It is a common butterfly, and it is not considered to be threatened or endangered at the moment. However, it is vulnerable to habitat loss and degradation.