The Grass Demon
Ancistroides folus(Udaspes folus), the grass demon, is a small but prominent butterfly found in India & Nepal that belongs to the skipper family, Hesperiidae and found in deciduous and semi-evergreen forests.They mostly roam during the rainy season. Rarely found in homesteads. It is regarded as an occasional pest of ginger and turmeric plants.
Distribution
They are found from Sri Lanka , South India to Saurashtra , Maharashtra , Gujarat , Madhya Pradesh , Uttar Pradesh , West Bengal , Himachal Pradesh and to the eastern countries such as Myanmar , China , Thailand , Malaysia , Indonesia ,Taiwan, Japan, Singapore etc. They can be seen everywhere in Kerala . They are also found in the Himalayan forests.
Description
It is a small butterfly with a wingspan of about 4 to 4.8 cm. It is black with a large white spot on the upperside of the hindwing and several smaller whites spots on the forewing. The underside of its wings is mostly white with brown edges and spots. The honeydew trunk is fairly long.
Habitat
The grass demon is to be found in deciduous and semi-evergreen forests. It prefers the edges of open spaces rather than the deep forest shade or open sunlight. It is most abundant in the more open regions of hilly jungle. It is also encountered on the plains at some distance from such terrain. It occurs up to 8,000 feet (2,400 m) in the hills of South India and up to 5,000 feet (1,500 m) in the Himalayas.
Habits
The grass demon prefers forest edges or clearings where dappled light is present. Its black and white colouration may have evolved to take advantage of the dappled light in these areas. The pied pattern which seems prominent in the open is effectively disruptive in the shade and the butterfly is difficult to locate once it settles down. It is a bold insect and not easily disturbed. It usually flies in the shade among bushes and under trees keeping low and close to the ground. From time to time, it takes short flights, and, occasionally, much longer excursions into the open clearings. Its flight is quick and the path is very erratic making it very difficult to track when in flight. It has the habit of sunning itself on leaves and stones in wetlands. When it is sunny, the hindwings are spread and the forewings are raised a little, and the wings are usually locked when resting. Both wings are stirred separately. It is a honey bee moth. Honey is drunk from the cremation plant and the sycamore plant. Sometimes nutrients are also seen from dung, bird droppings etc.
Life cycle
The butterflies emerge in February or March and lay eggs before they die. The eggs remain dormant till the rains, that is, usually the month of May, when they hatch. The caterpillars pupate in September and October and the adults emerge four to six months later. In some cases the caterpillars pupate later and in these cases the pupa remain dormant, throughout the dry season, till May when the rains begin.
Eggs
The female normally sits on the underside of the leaf of the host plant and lays a single egg. The egg is reddish and appears smooth and dome shaped. When about to hatch it turns white with a red top.
Larva
Soon after hatching, the caterpillar does not consume the eggshell completely and it makes itself a spacious cell and hides inside it. The caterpillar is sluggish and comes out to feed only at night. Even when disturbed it is reluctant to leave its cell.
The caterpillar is a light uniform leaf green colour with a dark green pulsating line on the back and a relatively small, dark head. The full grown larva has the habit of resting with the first three segments contracted, so as to give a humped appearance. It always lies closely applied to the leaf, by turning over a triangular piece from the edge onto the upper surface over itself. Specific host plants include Zingiber zerumbet
Pupa
Pupation takes place on the same plant within a cell. The pupa is long and cylindrical, watery green in colour. It has a long conical projection in front of the head. The eyes are easily seen but do not protrude out of the outline of the pupa. The pupa broadens towards the shoulders and the abdomen gradually tapers to the last segment.
The most striking characteristic of the pupa is its proboscis. It is long and thin generally extending up to and a little beyond the tip of the abdomen. The pupa is the same colour of the caterpillar and unmarked. It is covered in a thin layer of white powder. The body band is neither too tight nor too loose and allows the pupa to wriggle if disturbed.
Food
The grass demon feeds on ginger, turmeric, and their relatives Curcuma aromatica, Curcuma decipiens, Hedychium sp. and other plants of family Sctiaminae
