|( Linnaeus , 1758)|
Troides helena is a butterfly from the family of the knightly butterflies (Papilionidae)found in Asia. The specific epithet goes back to Helena (the "beautiful Helena") from Greek mythology . Carl von Linné classified the species as Papilio helena in the group of " Achaic Knights" ( Equites Achivi ).
The wingspan of the moth is 150 to 180 millimeters. There is a slight sexual dimorphism between the sexes . In the males, the upper side of the forewing is black, the upper side of the hind wing is bright yellow and has a black row of dots on the edge, tail processes are missing. Females differ in the whitish bordered veins on the upper side of the forewing and the double row of black dots on the upper side of the hind wing. The drawing of the underside resembles the upper side in both sexes.
Adult caterpillars are black-gray to brown-gray in color and have gray tubercles on the entire body surface . A whitish to pink saddle stands out in the middle of the body. To deter predators, the caterpillars are able to turn out an osmaterium .
Distribution, subspecies and habitat
The species occurs in northeast India , Thailand , Malaysia , Indonesia , Myanmar , Vietnam, and southern China . 27 subspecies are currently classified in the different occurrence areas . Troides helena primarily inhabits deciduous forests, but can also be found in gardens and parks.
Way of life
The moths fly in successive generations. They like to stay in higher tree regions and are persistent fliers. Their flight style is reminiscent of birds, which is why they are referred to as Common Birdwing in English . For food intake they visit flowers, such as lantana ( Lantana ). The males sometimes suckle on the ground at damp places in the earth in order to absorb liquids and minerals. It takes an average of 40 days from egg-laying to hatching. The caterpillars feed on the leaves of pipe flowers ( Aristolochia ). Since they absorb aristolochic acids with their food and store them in the body, they, like the moths later, are poisonous and thus largely protected from predators. The yellow hind wings of the moths are also to be understood as a warning color in this regard.
Hazard and protection
Since the caterpillars of Troides helena have a relatively narrow range of food plant species, the species is endangered wherever the necessary food plants disappear due to reclamation . Because of the attractiveness of the butterflies in terms of color, the species is also endangered by collectors and traders who have taken specimens from the wild. In Hong Kong , the species was therefore placed under protection by the responsible government agency, the Wild Animals Protection Ordinance . The food plant Aristolochia tagala was also protected.
- ^ Carl von Linné: Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus II. Editio decima, reformata. , Holmiae. (Salvius), 1758
- ^ Charles Thomas Bingham: The Fauna of British India, including Ceylon and Burma. Butterflies. Vol. II, Taylor & Francis, London, 1907
- ↑ Development cycle
- ↑ Distribution and subspecies
- ↑ a b Karen To: The Tragedy of the Beauty - Common Birdwing (Troides helena) In: Green Power, Green Country, Hong Kong, Vol. 125, April 2017 (accessed from http://www.greenpower.org.hk/ html5 / eng / ws_125.shtml on February 15, 2018)
- ifoundbutterflies - Butterflies of India
- learnaboutbutterflies - Common Birdwing
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