Winch swarmers
| Winch swarmers | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Windwarmers ( Agrius convolvuli ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Agrius convolvuli | ||||||||||||
| ( Linnaeus , 1758) |
_2.jpg)
The hornworm ( Agrius convolvuli ) is a butterfly ( moth ) from the family of moth (Sphingidae).
features
Characteristics of the adults
The moths reach a wingspan of 80 to 130 millimeters, with the females usually becoming somewhat larger. The forewings are unevenly colored light to dark gray or gray-brown and have a dark gray-brown pattern made of numerous fine, wavy or jagged bands. These patterns vary from non-existent to severe, depending on the individual. In the males it is usually much stronger and more conspicuous and is complemented by dark areas on the wings (weak sexual dichroism ). You can see two very fine black lines in the center of the forewings, between which the color of the wings in the males is usually a little darker. The hind wings are yellowish-gray to gray in color and, in addition to a washed-out, dark, elongated spot near the base, also have slightly curved transverse bands that are also colored. The outer edge of the wing is fringed with fine white and grayish brown. Sitting in the resting position, the moths imitate the surface of the bark with the coloring of their forewings ( bark mimicry ).
The whitish-gray antennae are 18 to 20 millimeters long in the males and 11 to 16 millimeters in the females. Like many other species of hawkmoth, they are bristle-shaped and only slightly thickened towards the tip. The proboscis of the animals is 50 to 139 millimeters long, on average it is 90 millimeters. This means that it is well over the body to almost twice as long. It is very resilient and elastic and, as is usual with butterflies, is rolled up below the head between the palps . The head of the animals, like the thorax, has fine gray hairs. The latter bears two fine, hairless, darkly colored, bell-shaped curved lines in the center, which together form a closed horseshoe-like shape.
At the base of the thorax there are two thicker black circular lines adjacent to it. The area enclosed by the bell-shaped lines is darker gray-brown in color in the males. There is a red-colored spot on each side of the metanotum .
The abdomen is colored gray-brown along the back. On the sides of the terga , the chitin plates on the back, each segment is colored pink at the front and black at the back. Only the first tergum has a strong red color. The moths are finely colored white between the segments.
With its wings open, the butterfly can be easily recognized from above by this characteristic color, similar to the privet hawk ( Sphinx ligustri ) , which is otherwise unmistakable with the species . It is rare to find individuals who instead of pink, yellow colored terga (forma pseudoconvolvuli ). The forma aksuensis , from the high areas of the Pamir and Tianshan, forms another color deviation : it is almost white in color.
Characteristics of the caterpillars
The caterpillars are about twelve centimeters long, thus reaching a size similar to that of the skull hawk, and with them they are among the largest in Europe. They are very variable in color. Their basic color ranges from green to yellow, orange and brown, to black, whereby these colors also occur in combination (e.g. orange and black). They have light, sloping side stripes and, underneath, dark, large stigmas . At the end of the abdomen they have a yellowish, completely harmless thorn that can go as far as black in the dark forms.
Similar species
The wind swarm is unmistakable in the eastern distribution area, in the western distribution area it can be confused with Agrius cingulatus . This species, which occurs mainly in South and Central America, is repeatedly detected on the western coasts of Europe. It can be distinguished on the basis of the clearly stronger pink coloration of the abdominal segments and an equally colored rear wing base. The caterpillars of the two species are also very similar, but none of Agrius cingulatus has been found in Europe . In addition, the forma pseudoconvolvuli of the wind swarm has a certain similarity to North American species of the genus Manduca , such as the tobacco hawk ( Manduca sexta ).
distribution
The year-round distribution area of the species is very large and extends over almost the entire Paleotropic and Australasia and the southern parts of the Palearctic . The wind swarmers can therefore be found in the tropics and subtropics of Asia and Africa , in and around Australia and the islands of Oceania (except New Zealand) and also in North Africa , the Mediterranean and Central Asia as far as Siberia . It is only missing in higher altitudes. As a migrant butterfly, the species opens up new areas in summer thanks to its persistent flight. It then occurs in Europe up to the far north, in Great Britain, Iceland and in large parts of Russia (in the east to Sakhalin ). In the southern hemisphere , the species can also be found in Tasmania and New Zealand .
The wind swarmers prefer open and temperature-favored landscapes, such as sunny slopes, bushy wasteland or fallow land , but occur everywhere except in dense forests. The species is also often found in potato fields and in suburbs on flower beds and hedges overgrown with bindweed .
Way of life
The winch hawk undertakes a significantly larger number of hiking flights than, for example, the skull hawk ( Acherontia atropos ). The species also reaches much more northerly areas, although it is more sensitive to temperature. This is also reflected in the fact that very few pupae survive the European winter. The nocturnal moths rest during the day with their wings folded like a roof over their abdomen on firm ground, such as on tree trunks, stones, electricity pylons or on the ground. In this position they are well camouflaged by their coloring.
Winch enthusiasts are excellent fliers and can reach peaks of up to 100 km / h. The average speed is still 50 km / h. Rain or wind does not affect their behavior. They are avid flower visitors and from dusk until around midnight they suck nectar from a variety of different flowers, such as petunias , lilies , soap herbs , miracle flowers , evening primrose , tobacco , phlox or thorn apples . The moths can be easily attracted by artificial light from around two hours after dusk. Mating usually begins at midnight and lasts into the morning hours.
Flight and caterpillar times
The first generation flies into Central Europe from May to June, the second generation develops there from mid-August to mid-October. For climatic reasons, the second generation has no chance of survival if it does not fly back.
Food of the caterpillars
The caterpillars feed especially on bindweed ( Convolvulus arvensis ), but also on bindweed ( Calystegia sepium ) and various ornamental bindweed. In their southern distribution areas, the caterpillars also feed on sweet potatoes ( Ipomoea batatas ) and bean plants .
development
The females lay their up to 1,000 eggs on the fodder plants, which are very small for the large moths with a diameter of only one millimeter. The caterpillars feed from July to September, hiding during the day and only eating at night. From August onwards, the caterpillars look for suitable places to pupate and are often seen on their way to the streets and paths. To pupate, they dig a hole the size of a hen's egg in the ground and pupate in it. The doll is ready after 10 to 14 days . It is red-brown and unmistakable due to the curved and protruding trunk sheath. The pupae are sometimes found during the potato harvest. Only the caterpillars, which pupate very early, create the metamorphosis to the butterfly and can fly back to the south. The rest of them try in vain to hibernate and die.
breed
The caterpillars are very easy to breed, and the resulting butterflies - especially the females - have long been assumed to be incapable of reproduction. However, this is a mistake, since egg maturation is delayed in Europe (except in the far south), which is interpreted to mean that the species here does not survive the winter and the females can thus start their return flight south to underneath the then matured eggs to be able to store suitable climatic conditions. Forced feeding with a honey solution consisting of one part honey and 10 parts water can keep the animals alive until the eggs have matured. To do this, you have to unroll the trunk with a suitable tool and immerse it in the liquid.
swell
Individual evidence
- ↑ a b c d Heiko Bellmann : The new cosmos butterfly guide. Butterflies, caterpillars and forage plants. Franckh-Kosmos, Stuttgart 2003, ISBN 3-440-09330-1 , p. 94f.
literature
- Günter Ebert (Ed.): The Butterflies of Baden-Württemberg Volume 4, Moths II (Bombycidae, Endromidae, Lemoniidae, Saturniidae, Sphingidae, Drepanidae, Notodontidae, Dilobidae, Lymantriidae, Ctenuchidae, Nolidae). Ulmer Verlag Stuttgart 1994. ISBN 3-8001-3474-8
- Manfred Koch , Wolfgang Heinicke: We identify butterflies. 3. Edition. Neumann, Radebeul 1991, ISBN 3-7402-0092-8 .
- Rolf Reinhardt, Kurt Harz: Migratory swarmers. Skull, curling, oleander and line swarmers . [The New Brehm Library, Vol. 596]. Westarp & Spektrum, Magdeburg, Heidelberg, Berlin and Oxford 1996, ISBN 3-89432-859-2
- Hans-Josef Weidemann, Jochen Köhler: Moths. Weirdos and hawkers. Naturbuch-Verlag, Augsburg 1996, ISBN 3-89440-128-1 .
