Lime Butterfly:

Common in the lowlands

by K.G.H. Munidasa

The Lime Butterfly Papilio demoleus demoleus "Dehirisiya" (Sinhala) belongs to the family Papilionedae, which is represented in Sri Lanka by 15 species.

The butterflies of this family are popularly called "Swallowtails" owing to the fact that most of them are seen to sport fairly long appendages on their hind wings in flight.

A medium-sized butterfly has a wingspan of 80-90 mm. The Lime Butterfly may readily be distinguished by its rich yellow speckling on the wings and body. It occurs in both the Low-Country Wet and Dry Zones, becoming more common during the annual migrating season of the butterflies from about October to March.

The Lime Butterfly deposits its eggs chiefly on the lime tree, hence its popular name, and also in Orange, Bael, Manderine (Naran), Pomelo and various other plants of the Rutacea family, and the larvae feed on the leaves of these plants until pupation.

However, in the Low-Country Dry Zone, I have often collected eggs and the larvae from the Satinwood and Woodapple (Divul) trees, both belonging to the above family. For the purpose of ovipositing (laying eggs) it favours low saplings than high trees, and the egg is laid in the tender leaves.

The egg is pale yellow in colour, but turns rather brownish towards hatching. The newly hatched larva is 2.5 mm. long and as with all others in the family resembles a bird's dropping, being black with a whitish V-shaped mark in the middle of the body.

Soon after hatching the larva consumes the empty egg-shell as its first meal. Passing several stages of moulting (shedding skin for new growth), the larva reaches maturity by about the 17th day after hatching from egg.

The full grown larva is 34 mm. long and 7 mm. broad.

As a whole it is yellowish green, with discs in the front and rear, each equipped with a pair of brown horns, whose tips are yellow.

Burnt sienna coloured patches on either side of body, starting from the white marginal band below and slanting upward are conspicuous. There is another shorter, similar coloured patch at the base of the 10th segment. These patches are thinly speckled with yellow and brown.

Three spots of similar colours are on the dorsum of segments 8, 9 and 10th.

Above the spots are two sharp fleshy black processes, tipped white. The legs and pro-legs are brown, the latter covered with soft hairy growth.

At the end of the larval period of between 15 to 17 days, the larva stops feeding and prepares itself for pupation on the underside of a leaf stalk.

The pupa is generally inactive and well camouflaged. It measures 30x9 mm. rounded and overall green in colour, paler towards the tail-end and yellowish on the back.

On the back are several rows of short tubercular processes and on the underside are more processes over the front wing-bud.

The pupa is bent backward and dorsally broad and stocky. The head is swollen, the frontal projection almost absent and its margin slightly curved. The thorax is high but less pointed. The adult butterfly emerges from the pupal case within 9 to 11 days time and hangs downwards a while, until the blood containing oxygen passes to the wings through the vein system.

This process takes from 30 to 45 minutes, before the wings expand and dry up enabling the insect to fly away. The photographs were taken by the writer after breeding the butterfly at home in large-mouthed bottle, from egg to adult state.

This is the easiest method to study the life cycle of a butterfly, at firsthand.

Full-grown larva	Adult insect sipping its first meal