Acherontia styx
| Acherontia styx | ||||||||||||
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Acherontia styx |
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| Acherontia styx | ||||||||||||
| Westwood , 1847 |
Acherontia styx is a butterfly ( moth ) that occursin large parts of East and Southeast Asiafrom the family of swarmers (Sphingidae) and the sister species of the death's head swarm that occurs in Africa and Europe. Both the generic name Acherontia and the specific epithet styx are named after Greek rivers of the underworld, Acheron and Styx . The motivation is the gloomy appearance of these butterflies, especially the "skull" on the thorax .
The species develops very quickly under ideal conditions; only ten days are then required for development from oviposition to pupation . The species can cause damage in agriculture, especially sesame ( Sesamum indicum ).
features
Eggs and caterpillars
The pale green eggs are 1.2 by 1.5 millimeters in size and have a shiny and smooth surface. Shortly before hatching, they turn yellowish-green.
The caterpillars reach a body length of 90 to 120 mm and appear fully grown in a green, yellow or brown basic color. After hatching, they are around five millimeters long and then have a yellowish-green color that is covered with a dull layer. Their anal horn is long, black, and forked at the tip. From the second caterpillar stage, lateral stripes and numerous small white tubercles appear on the body. It is only in the fourth stage that the caterpillars have the same coloration as they are when fully grown.
In the fifth and final stage, they look very similar to the caterpillars of the skull hawk, but are each dotted more dark blue on the back on the back half of each segment. The anal horn is also less curved and the tip is not curved back. The caterpillars with the green base color have a dark green head, each with a wide black stripe on the cheek. The second to fourth body segment is yellow-green, the rest of the body is grass-green. Its back and the sides of the fifth to eleventh segment have dark blue dots on the back half, and seven sharply defined yellow diagonal stripes run along the sides of these segments. Each of these stripes extends backwards near the back to the following segment, the last stripe on the eleventh segment extends to the base of the anal horn. The stripes are limited to dark blue at the top, this color is sharply delineated towards the stripe and diffuses towards the top. The anal horn is canary yellow, the thoracic legs are black. The belly legs and the pusher are green, the anal valve is bordered in green and yellow. The oval stigmas are yellowish-white, in the middle velvet-black and brownish-green bordered.
The yellow caterpillars also have a green head, the rest of the body is canary yellow and otherwise has the same pattern as the green animals. The brown caterpillars have an ocher-colored head with dark brown stripes on the cheeks. On the second to fourth segment there is a wide black stripe on the back, and below that on each side another wide ocher-colored stripe. On each segment there is a brown dotted and dashed area behind the spiracles. In addition, there is an oval brown spot on the second segment on both sides of the back. The oblique stripes on the side of the abdomen are purple, the anal horn is ocher-colored. The thoracic and abdominal legs are black, the pusher is brown.
Doll
The pupae are 50 to 60 millimeters long and are very similar to those of the skull hawk. They have the same mahogany color, but this is paler. The antennae are slightly longer than the front legs. The Kremaster is squat and triangular, its back is wrinkled. Its tip ends in two small teeth, each with a bristle.
butterfly
The moths have a wingspan of 89 to 130 millimeters and are large and powerfully built. They are similar in color to the closest related skull hawk ( Acherontia atropos ). The forewings are large and dark in color, the hind wings are yellow and have a black submarginal band. There is a skull-shaped drawing on the back of the thorax . They differ from the related species in that they have two dark bands on the underside of the forewing instead of one in the middle and, as a rule, the lack of dark bands on the abdomen of the abdomen. The "skull drawing" on the thorax is darker and on the upper side of the hind wings near the anal angle there is a faint bluish spot within the black submarginal band. Finally, the central point on the forewings is also orange instead of white.
♂ Dorsal view
△ ♂ Anterior view
♀ Dorsal view
△ ♀ Anterior view
Caterpillar
Occurrence
The nominate subspecies occurs from north central China , west China and north Thailand to the west via Myanmar , Bangladesh , India , Nepal , Pakistan and Iran to Saudi Arabia and Iraq . The subspecies A. s. medusa is distributed in the east of continental Asia, from northeast China, where it occurs as a migratory butterfly, and Japan south over east China to Vietnam , Malaysia and Thailand. They can also be found on the islands of the Malay Archipelago from Sumatra , Borneo and the Philippines east to the Moluccas .
The species is not one of the regular migratory butterflies , but can occur sporadically every year north to Heilongjiang . It prefers to settle in hot, open areas at low altitudes, also with agricultural use.
Way of life
The adults feed on honey by entering beehives , but are also known to prick fruit with their proboscis and are considered pests on yuzu ( Citrus x junos ) in South Korea, for example .
Flight and caterpillar times
The species occurs across China in two generations per year and flies from May / June to August. The caterpillars can be found here from June to September. In Korea, the moths fly from late July to mid-September.
Food of the caterpillars
The caterpillars are polyphagous and feed on a wide variety of plant species. Most can be found in the families trumpet tree (Bignoniaceae), legume (Fabaceae), olive tree (Oleaceae), sesame family (Pedaliaceae), nightshade family (Solanaceae) and verbena family (Verbenaceae). In addition, one finds occasionally used food plants in 11 other families.
In China, the caterpillars were found on loosestrife ( Clerodendrum ), privet ( Ligustrum ), tomatoes ( Solanum sect. Lycopersicon ), sesamum , nightshade ( Solanum ) and various types of legumes. In Japan they are made from sesame ( Sesamum indicum ) and jasmine blossom nightshade ( Solanum laxum ), in Korea from eggplant ( Solanum melongena ), potato ( Solanum tuberosum ), paprika ( Capsicum annuum ), pea ( Pisum sativum ) and bluebell tree ( Paulownia tomentosa ) known.
Occasional mass occurrences are known in India, which can cause damage to agriculture, particularly sesame seeds.
development
The females lay their eggs individually on the underside and upper side of the leaves in the peripheral areas of the host plants. The caterpillars usually hatch after three to five days and first eat the eggshell. As they grow, the caterpillars become increasingly sluggish and ultimately only stay on two or three branches of the food plants. Development takes place very quickly at 40 ° C and only takes 10 days from oviposition to pupation. In contrast to the skull hawk, pupation rarely takes place more than 10 centimeters deep in the ground. The earth chamber in which pupation takes place has smooth inside. The pupa is usually in the wintering stage of the species and tolerates extreme drought and humidity very well.
Specialized enemies
It is known from India that the caterpillars are parasitized by the parasitic wasp species Quandrus pepsoides . This lays its eggs on the eggs of its host. Up to 20 larvae develop in the eggs of the swarmers, which then change color to black and white as the parasite larvae develop. The parasitic wasp Trichogramma chilonis is also known from India as a parasitoid of the eggs of Acherontia styx . In a study there, leaves with eggs were collected and the development of the eggs was monitored in the laboratory. Depending on the year of investigation, 72.3 to 87.8% of the eggs were parasitized by Trichogramma chilonis . In field observations also carried out in the context of this study, T. chilonis and other predators destroyed a total of 96.3% of the eggs.
Taxonomy and systematics
The genus name Acherontia is derived from Acheron , one of the five rivers of the underworld from Greek mythology . The specific epithet is derived from the Styx , another river of the underworld from Greek mythology. The names of the two other species of the genus also have reference to the Greek underworld: Atropos and Lachesis are goddesses of fate and two of the three Moiren .
On the basis of morphological studies of adults, caterpillars, pupae and host plants, it could be shown that Acherontia styx is closely related to Acherontia atropos , the sister taxon of the two species is Acherontia lachesis .
The following relationships result in the genus Acherontia :
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In addition to the nominate subspecies , a subspecies Acherontia styx medusa has been described. The individuals occurring in Shanghai , Guangdong and Hong Kong are typical representatives of Acherontia styx medusa , those from Tibet , Sichuan and Shaanxi belong to the nominate subspecies. On the east-west borderline between these regions, more or less intermediate animals appear. In Vietnam, too, some of the animals are trained in this way. Hence, it appears that the A. s. medusa is just one color variant that occurs in damp habitats.
swell
Individual evidence
- ↑ a b c d e f g h i j k l m n o Sphingidae of the Eastern Palaearctic. AR Pittaway, accessed September 27, 2009 .
- ↑ Sphingidae of the Western Palaearctic. AR Pittaway, accessed October 1, 2009 .
- ↑ Pala Ram, RK Saini and SS Sharma: Natural biological control of til hawk moth, Acherontia styx Westwood on sesame . Ed .: Department of Entomology, CCS Haryana Agricultural University.
- ^ A b Ian J. Kitching: Phylogeny of the death's head hawkmoth, Acherontia [Laspeyres], and related genera (Lepidoptera: Sphingidae, Acherontiini) . Systematic Entomology 28 (2003), pp. 71-88.
literature
- AR Pittaway: The Hawkmoths of the western Palaearctic. Harley Books, 1993, ISBN 0-946589-21-6 .
