Mythimna unipuncta

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Mythimna unipuncta
Mythimna unipuncta

Mythimna unipuncta

Systematics
Superfamily : Noctuoidea
Family : Owl butterfly (Noctuidae)
Subfamily : Hadeninae
Genre : Mythimna
Subgenus : Pseualetia
Type : Mythimna unipuncta
Scientific name
Mythimna unipuncta
( Haworth , 1809)
Tense butterfly

Mythimna unipuncta , also known as the single-point reed owl , grain white-veined owl , army worm owl or wandering reed owl, is a butterfly ( moth ) from the family of the owl butterflies (Noctuidae). In some regions the species is classified as a pest on cereals (maize, rice).

features

The moths reach a wingspan of 33 to 44 millimeters (up to 45 mm, 41 to 48 millimeters). The fore wing is rather elongated with a pointed apex and a rounded tornus. The basic color of the forewings is reddish to yellowish brown with alternately more intense, darker dusting. The outer, jagged transverse line is drawn very faintly darker, usually only indicated by dark brown points on the veins of the wings. The kidney defect is indicated by a white spot that sits at the distal end of the middle cell. Occasionally, the remaining kidney flaws can also be guessed by a slightly lighter color than the basic color. The area is surrounded by a slightly darker shadow. In some specimens, the ring flaw also stands out from the base color by a slightly lighter color. A slightly darker apical line is always clearly developed. The wing veins and the fringes are kept in the basic color, but often also lighter, sometimes only individual wing veins.

The hind wings are whitish, often with a gray-brown over-dusting. The wide fringe is darkly colored. The wing veins are darker here, the fringes light ocher.

The milky white, hemispherical egg is smooth on the outside.

The caterpillar is brown-gray, greenish brown to reddish brown in color, and almost black specimens are also found. As an adult, it becomes 38 to 43 millimeters long (or 24 to 35 millimeters). The top is mottled dark. The head is light brown with a darker pattern, the neck plate is black. The back line and the side back lines are light, but rather indistinct. The ocher-colored side stripe is also rather narrow and slightly raised. However, the light orange-colored belly side is very clearly demarcated.

The doll is colored brown and has a conical cremaster , which is covered with two downwardly curved, pointed bristles and four, hook-like, fine bristles.

Similar species

The species is similar to the white-point grass owl ( Mythimna albipuncta ) and the hooded grass owl ( Mythimna ferrago ). In both types, the inner and outer transverse lines are either formed or at least partially indicated. In Mythimna unipuncta , the inner transverse line is completely absent, the outer transverse line is very rarely delicately drawn, usually only indicated as a row of dots. In Mythimna unipuncta the apical line is always very clearly developed, while in the other two species it is only indicated. The white point in Mythimna unipuncta is quite small. Often it sits at the end of a dark or light welt, which the other two species lack. In Central Europe, the moths of Mythimna unipuncta often only arrive (October / November) when the flight times of the moths of the other two species are usually over. However, individual moths of the hooded grass owl can be found in some years until November.

Geographical distribution and habitat

The species is widespread and occurs in North America, the Hawaiian Islands, in some areas of South America, in southern Europe, North Africa, the Sahel region of Africa, East Africa to Central Asia and Bangladesh in the east. In the tropical-subtropical and warm temperate areas it is indigenous, in the temperate zones it flies in as a migratory butterfly more or less regularly every year and is thus also found in Central and Northern Europe. In the north it can occasionally even reach Iceland. In Western Europe it has been found sporadically on the British Isles since the beginning of the 19th century. Since the late 1950s it has appeared there in larger numbers and regularly every summer. It was first recorded in Central Europe at the beginning of the 20th century, for example in 1904 in South Tyrol, 1906 in Austria, 1913 in Switzerland, 1929 in Germany, 1960 in the Netherlands, 1962 in Romania, 1966 in what was then Czechoslovakia and 1970 in Hungary. The first finds were made in Iceland and Denmark as early as 1959, and in 1978 also in Norway. It is also found on the mid-Atlantic islands (Azores, Canary Islands, Madeira), where it occurs particularly as a pest in the Azores.

Mythimna unipuncta occurs in warm, dry to moist habitats, where the caterpillars have a corresponding food supply of grasses i. w. S. find. Because they love to migrate, they can be found in almost all biotopes in their area of ​​distribution.

Way of life

Mythimna unipuncta forms three to four generations per year in southern Europe, the adults of which fly from March to December. New generations are constantly being produced in breeding under optimal temperature conditions. In this way, up to six generations can be formed per year. In Central Europe, the species of each species often does not migrate until late in the year (October / November), apparently only animals of the third and fourth generation. In England, however, the moths appear from August to October. Caterpillars have also been found here; H. the species can reproduce in summer. However, the caterpillars, the wintering stage in other regions, are very susceptible to frost and as a rule should not survive the central and western European winter. The moths are nocturnal, come to artificial light sources and can also be baited. They suck nectar from flowers. The females lay the eggs in rows or in piles in the folded leaves of grasses or under the leaves. On average, each female lays around 100 eggs. The egg caterpillars hatch after 4 to 10 days (or 5 to 13 days). They are two to four millimeters long. The caterpillars usually eat the leaves of their food plants, but can also eat their way into the stems. The caterpillars are mostly nocturnal. Ahola & Silvonen name the following food plants for Europe:

The caterpillars overwinter in the regions where the species is indigenous. After the sixth larval stage, the caterpillars pupate in a loose cocoon on the ground between the food plants. The moths hatch after one to two weeks of pupal rest.

Life cycles of Mythimna unipuncta in different regions

There are quite different statements in the literature about the life cycle of the species; this is to be expected due to the wide geographical distribution under different climatic conditions. In the tropical climate of Bangladesh , MZ Alam observed five generations, with the fifth generation caterpillars going through a diapause of up to 132 days in winter before continuing their development. On average, each female laid 106 eggs, which are laid in piles in the folded fresh or dry leaves of the host plants. The egg caterpillars hatch after 5 to 13 days and initially eat the young leaves. They are initially diurnal, later they only eat at night and hide during the day. In the fifth and sixth instar, the caterpillars become gregarious and migrate to forage. Since 80 percent of the caterpillar's total food is not consumed until the sixth larval stage, it is at this stage that they cause the most damage, in this case to rice plants. The larval stage lasts only 20 to 48 days, depending on the temperature, with the exception of the overwintering generation. Pupation takes place in the earth; the doll rest only lasts 7 to 29 days. The first moths of the overwintering generation appeared in the observation year (1957) from early April to early May. The first generation moths appeared in early June. The second generation of butterflies appeared at the end of July and the third generation of butterflies at the end of August / beginning of September. The fourth generation moths flew from mid-October to early November. The population reached its peak numerically, while the subsequent fifth, wintering generation was numerically much smaller. Therefore, the greatest damage to the rice plants was caused by the fourth generation caterpillars in October. It is possible that this description is already about the sister species of M. unipuncta , Mythimna separata , since Hacker et al. (2002) indicate an eastern limit of distribution in northern Pakistan, where Mythimna unipuncta " lives sympathetically with its eastern sister species (ie Mythimna separata )". The separation of this species was made by Franclemont in 1951 and Mythimna unipuncta from Bangladesh could be a misidentification.

In the province of Māzandarān in northern Iran, the caterpillars of Mythimna unipuncta also occasionally cause damage to rice plantations. Here in this area, bordering the Caspian Sea to the south , three generations are formed per year, with the greatest damage being done by the second generation caterpillars. The moths flew there in early July, mid-August and in September.

In the US state of Illinois, the moths migrate from the southern states of the USA as early as April and May. Here, too, any overwintering caterpillars are unlikely to survive the harsh winters. You can form up to three generations here in summer. The egg caterpillars hatch a week or two after the egg is deposited. The second generation moths fly in late June / late July, the third generation moths fly in late August to early September. The caterpillars are nocturnal, during the day they hide under plant remains or in the top centimeters of the soil.

Systematics and taxonomy

The taxon was first scientifically described in 1809 by Adrian Hardy Haworth as Noctua unipuncta . The holotype comes from England, an indication that the species occasionally flew into England as early as the early 19th century. The species was later added to the genera Leucania Ochsenheimer, 1816, Pseudaletia Franclemont, 1951 and Sideridis Hübner, 1821 and therefore also appears in the literature in the combinations Leucania unipuncta , Pseudaletia unipuncta and Sideridis unipuncta . Leucania Ochsenheimer, 1816 and Siderides Hübner, 1821 are other genera to which unipuncta cannot be placed. Pseudaletia Franclemont, 1951 is today either regarded as a synonym of Mythimna Ochsenheimer, 1816, or is placed as a subgenus of Mythimna .

Harmful effect

The white-point grass owl is a migratory butterfly and is not indigenous to Central Europe. It is considered a pest on grain in North America, and as a pest on corn in southwest Europe. In Bangladesh (formerly East Pakistan) the species is known to pest rice.

supporting documents

Individual evidence

  1. ↑ Red list at Science4you
  2. ↑ a b c d e f g h i j Carter (1984: p. 285/6)
  3. ↑ a b c d e Hacker et al. (2002: p. 179)
  4. ↑ a b UK Moths - Ian Kimber's website ( memento of the original from October 12, 2012 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / ukmoths.org.uk
  5. ↑ a b c Integrated Pest Management
  6. ↑ a b c Ahola & Silvonen (2009: p. 439/40)
  7. ^ Forster & Wohlfahrt (1971: p. 99)
  8. ^ A b Adrian Hardy Haworth: Lepidoptera Britannica: sistens digestionem novam insectorum lepidopterorum quae in Magna Britannia reperiuntur, larvarum pabulo, temporeque pascendi; expansions alarum; mensibusque volandi; synonymis atque locis observationibusque variis; adjunguntur dissertationes variae ad historiam naturalem spectantes info. London, J. Murray, 1809-1823 Online at Google Books (description on p. 174)
  9. ↑ João Tavares: Mythimna unipuncta (Haworth) (Lep., Noctuidae) aux Açores. Bioecologie et lutte biologique . Thèse de Doctorat d'État Ès-Sciences, Université de Droit d'Économie et des Sciences d'Aix-Marseille, 203 pp., 1989 abstract
  10. ↑ a b Ebert and Steiner (1998: pp. 286–288)
  11. ↑ a b c d M. Z. Alam: On the biology of rice ear-cutting caterpillar, Pseudaletia unipuncta (Haworth) in East Pakistan. Agriculture Pakistan, 11 (4): 560-572, 1960 abstract
  12. ↑ a b H. Abbasipour: An Identification of Mythimna species in the West of Mazandaran rice fields and population fluctuations of the dominant species. Iranian Journal of Agricultural Sciences, 37 (4): 687-695, 2006. Abstract  ( page no longer available , search in web archives )  Info: The link was automatically marked as broken. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / www.sid.ir  

literature

  • Matti Ahola and Kimmo Silvonen: Larvae of Northern European Noctuidae. Vol. 2. 672 pp., 2008 ISBN 978-952-92-2888-1
  • David J. Carter: Pest Lepidoptera of Europe with special references to the British Isles. 431 S., Dr. W. Junk Publishers, Dordrecht 1984 ISBN 90-6193-504-0 .
  • Günter Ebert, Axel Steiner: The butterflies of Baden-Württemberg Volume 7, Nachtfalter V (Owls (Noctuidae) 3rd part), Ulmer Verlag Stuttgart 1998. ISBN 3-800-13500-0
  • Walter Forster , Theodor A. Wohlfahrt : The butterflies of Central Europe. Volume 4: Owls. (Noctuidae). Franckh'sche Verlagshandlung, Stuttgart 1971, ISBN 3-440-03752-5 .
  • Hermann Hacker, László Ronkay and Márton Hreblay: Noctuidae Europaeae vol. 4 Hadeninae I . Entomological Press, Sorø 2002 ISBN 87-894-30-07-7

annotation

  1. ↑ The German names are completely unusual because they are not a down-to-earth species. None of the above common names is mentioned in the Lepiforum or in the standard work The Butterflies of Baden-Württemberg.

Web links

Commons : Mythimna unipuncta  - collection of images, videos and audio files