Orange oakleaf

Appearance

The butterfly wings are shaped like a leaf when in the closed position. When the wings are closed, only the cryptic underside markings are visible, which consists of irregular patterns and striations in many shades of biscuit, buff, browns, yellow, and black. The veins are darkened and resemble the veins of a leaf. The resemblance to a dried leaf, a masquerade, is extremely realistic and gives the genus its common names, the oakleaf or dead leaf.

When the wings are open, the forewing exhibits a black apex, an orange discal band and a deep blue base. There are two white oculi, one along the margin of the apical black band, and the other bordering the orange and deep blue areas. The hindwing is more uniformly blue but diffused with brown patches along the termen.

Male and female butterflies are similar except that the female is generally larger and has the apex of the forewing protrude to form a longer point. Females also tend to be more reddish on the underside and the yellow mottled markings tend to be paler. The butterfly exhibits polyphenism, i.e. there are specific dry-season and wet-season forms which differ in colouration and size; the wet-season form tends to be smaller.

The wingspan of the butterfly ranges from 85 to 110 millimetres.

Distribution

The orange oakleaf is found in India, Nepal, Bhutan, Bangladesh, and Myanmar, down to Tenasserim Hills. In Southeast Asia it occurs in southern China, Thailand, Laos, Taiwan, and Vietnam. It has been also recorded from Pakistan in 2000.

In India, the butterfly flies in the Himalayas at low elevations, from Jammu and Kashmir, through Garhwal and Kumaon to West Bengal, Sikkim, Arunachal Pradesh, and other states of the northeast. It is also found in central and peninsular India; it flies in Madhya Pradesh, Jharkhand, Chhattisgarh, Orissa and Andhra Pradesh; i.e. along the central Indian highlands to Pachmarhi and Amarkantak, the Western Ghats south to Bhimashankar, and in the Eastern Ghats north of the river Godavari.

Behavior

In the Himalayas, the butterfly is multivoltine and flies from April to October. Kehimkar records the butterfly on the wing in India from April to December.

In Chongqing one generation has been recorded as taking about 50 days from egg to imago. The egg period lasted about 6 days, the larval period 36 days, and involved 5 to 6 instars and with the pupation lasting about 10 days. The caterpillars bred successfully at temperatures of 22 to 31.5 °C and relative humidity of 48 to 98%. The larval period could be reduced from 36 days in natural conditions to 16.8 to 23 days in captive breeding.

In another study in China, in the Emei mountains ), the butterfly has three generations a year in which the first and second generations predominate. Most of the second generation, along with a few of the third and sometimes the first generation, go through the winter as diapaused adults. Most second generation adults diapause in early July.

Butterflies of the first generation, reared in captivity in the Emei mountain study, completed their life cycle in 45 to 54 days, with eggs taking 4 to 6 days, caterpillars 21 to 36 days and pupation 10 to 15 days. The breeding took place in temperatures between 26.4 and 28.2 °C and humidity of 63.2% to 84.7% on average.

Investigations in an artificial climate chamber reveal that photoperiod and temperature play a role in the larval development and survival rate of the larvae of ''K. inachus''. Photoperiods affect the development period of larvae at 20 °C but not at 25 °C and 30 °C . As temperature increased from 20 °C to 25 °C and 30 °C, the developmental periods of larvae reduced under the same photoperiod to 31.7 to 36.0 days, 26.37 to 27.4 days and 21.0 to 21.5 days,respectively.

Increasing temperature also made an increase in the survival rate under different photoperiods. The survival rate of larvae at 20 °C, 25 °C, and 30 °C was 80%–92%, 75%–95%, and 55%–85%, respectively. The low survival rate at 30 °C under most photoperiod gradients requires that artificial breeding of ''K. inachus'' be done below this temperature.

Reproduction

The late stage caterpillar is velvety black, covered with rather long yellowish hair. It has a large number of reddish spines; eleven on each segment, with one dorsal, two subdorsal and three lateral on each side.

Food

The larvae are polyphagous, feeding on plants from many families. The list of food plants include:
⤷  Urticaceae – ''Girardinia diversifolia'' in India
⤷  Polygonaceae – ''Polygonum orientale'' in India
⤷  Rosaceae – ''Prunus persica'' in India
⤷  Acanthaceae:
⤷ * ''Dicliptera chinensis'' in China
⤷ * ''Hygrophila salicifolia'' in Japan
⤷ * ''Lepidagathis formosensis'' in Taiwan
⤷ * ''Ruellia capitataus'' in India and Taiwan
⤷ * ''Rostellularia pracumbens'' in China
⤷ * ''Strobilanthes'' species, in China and Japan, including:
⤷ **''S. flaccidifolius'' in Japan
⤷ **''S. glandulifera'' in Japan
⤷ **''S. tashiroi'' in Japan