HONG KONG BUTTERFLIES
99
A white, suffused dorsal patch, or smear, is on the fifth and sixth segments, extending down the sides. Half grown the creature is bright moss green and the processes become obsolete. The protective armament of all Papilio larvae is known as the osmeterium. From this gland it can protrude two forked filaments emitting an odour which is highly pungent, resembling certain dried fruits. In the case of P. paris the filaments are orange and it extends them when disturbed or annoyed. The pupa is subangular, the general colour bright green, the dorsal and wing ridges light yellow. The head is cleft very obtusely, forming two projections. It is attached to a twig by a cremestral pad at the tail, and a silk girdle. Its coloration makes it extremely hard to detect, and the pupa is rarely found until the imago has emerged, when the empty case, the shade of skimmed milk, renders it conspicuous.
Practically all the Papilio larvae feed on the upper side of the leaf, and are consequently much easier to find than those of other families. Chilasa clytia, whose caterpillars are dark brown with vivid primrose streaks, is a case in point. The food plant is Litsea sebifera, and it seems to affect seedlings so that half a dozen larvae in various stages of growth, vie with each other to attract the human eye.
MODEL AND MIMIC
Anything in motion attracts the human eye, and butterflies on the wing are conspicuous objects. In nearly every case the upper sides of the insects would make concealment difficult, even at rest were the wings to remain spread. Whereas a moth on alighting chooses a background to suit the coloration, and pattern of its forewings which cover the often more brilliantly marked hind, the butterfly rests with folded members cocked up, and merely exhibiting the under pattern. This is usually marvellously broken up to suit the insect's normal surroundings and confers upon it a cloak of invisibility.
In flight the butterfly relies on speed to evade its main enemies the birds, and those species which have a weaker movement such as the Pieridae rely on its irregularity to dodge their foes. If one of these is met by a collector in a ride it will practically always slip over or under the net, and the only assured way of capture is to strike when the insect is past, with a following sweep.
HONG KONG BUTTERFLIES
99
A white, suffused dorsal patch, or smear, is on the fifth and sixth segments, extending down the sides. Half grown the creature is bright moss green and the processes become obsolete. The protective armament of all Papilio larvae is known as the osma- terium. From this gland it can protrude two forked filaments emitting an odour which is highly pungent, resembling certain dried fruits. In the case of P. paris the filaments are orange and it extends them when disturbed or annoyed. The pupa is subangular, the general colour bright green, the dorsal and wing ridges light yellow. The head is cleft very obtusely, forming two projections. It is attached to a twig by a cremestral pad at the tail, and a silk girdle. Its coloration makes it extremely hard to detect, and the pupa is rarely found until the imago has emerged, when the empty case, the shade of skimmed milk, renders it conspicuous.
Practically all the Papilio larvae feed on the upper side of the leaf, and are consequently much easier to find than those of other families. Chilasa clytia whose caterpillars are dark brown with vivid primrose streaks, is a case in point. The food plant is Litsea sebifera, and it seems to affect seedlings so that half a dozen larvae in various stages of growth, vie with each other to attract the human eye.
MODEL AND MIMIC
Anything in motion attracts the human eye, and butterflies on the wing are conspicuous objects. In nearly every case the upper sides of the insects would make concealment difficult, even at rest were the wings to remain spread. Whereas a moth on alighting chooses a background to suit the coloration, and pattern of its forewings which cover the often more brilliantly marked hind, the butterfly rests with folded members cocked up, and merely exhibiting the under pattern. This is usually marvellously broken up to suit the insects normal surroundings and confers upon it a cloak of invisibility.
In flight the butterfly relies on speed to evade its main enemies the birds, and those species which have a weaker movement such as the Pieridae rely on its irregularity to dodge their foes. If one of these is met by a collector in a ride it will practically always slip over or under the net, and the only assured way of capture is to strike when the insect is past, with a following sweep.
}
No comments yet.
Private notes are available after approval.