Chrysolina hyperici

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Chrysolina hyperici
2017 10 11 Chrysolina hyperici1.jpg

Chrysolina hyperici

Systematics
Subordination : Polyphaga
Family : Leaf beetles (Chrysomelidae)
Subfamily : Chrysomelinae
Genre : Chrysolina
Subgenus : Hypericia
Type : Chrysolina hyperici
Scientific name
Chrysolina hyperici
( Forster , 1771)
Dorsal view
Before departure

Chrysolina hyperici is a beetle from the leaf beetle family (Chrysomelidae).

features

The beetles are between 5 and 7.3 millimeters long. Their basic color is dark metallic green or bronze, sometimes also reddish or blue-black. The pronotum and elytra can be of different colors. The wing covers have loose rows of deep points (maximum 21 points in the two outer rows). The points of the wing coverts often have a border of a different color.

Similar species

The species Chrysolina hyperici can only be distinguished with certainty in genital morphology from the species Chrysolina quadrigemina, which also lives on Hypericum .

distribution

The beetle species is native to the western Palearctic (Europe, North Africa, Iran). It is widespread in Europe and is also found in the British Isles.

In the 1930s, the species was introduced to Australia together with C. quadrigemina and Anaitis plagiata (all insects that only eat St. John's herbs ( Hypericum )) in order to control the spread of St. John's herbs there.

In North America these three insect species were also introduced in the 1950s. In North America, the distribution area of ​​the beetle species extends mainly to the east and west coast of the USA and Canada as well as Ontario . The biological control of St. John's herbs is also intended to counteract the spread of the fungal pathogen Colletotrichum gloeosporioides .

Way of life

The beetles prefer warm and dry locations as their habitat. Host and fodder plants of the beetle species are various St. John's wort, in particular hairy St. John's wort ( Hypericum hirsutum ), spotted St. John's wort ( Hypericum maculatum ), real St. John's wort ( Hypericum perforatum ) and winged St. John's wort ( Hypericum tetrapterum ). The adults feed on the leaves and flowers of the plant genus, the larvae on the leaves and stems. The adult beetles can be observed from May to September, with these often entering a diapause in July . In autumn the females lay up to 2000 reddish eggs on the basal leaves of their forage plants. The species overwinters both as an egg and as an imago, with the latter often not surviving February. The larvae hatch in spring and then pupate in the ground in late spring.

Biological pest control

The two closely related and similar species Chrysolina hyperici and Chrysolina quadrigemina were introduced into numerous areas by humans in order to combat the St. John's wort , which was previously naturalized as a neophyte from Europe, Hypericum perforatum . This species had developed into a dreaded weed, especially on pastureland, which formed square-kilometer large populations and thus devalued entire stretches of land economically. Both species belonged to a whole range of biological antagonists, they were released in large-scale campaigns, sometimes with hundreds of thousands of specially bred individuals. Chrysolina hyperici was established in Australia in 1930, New Zealand in 1943, in the USA in 1945 and in Canada in 1951, making it one of the earliest species worldwide that were tested and used for this purpose.

The release of the leaf beetle species is generally considered to be a great success. In Australia, 800,000 hectares of pasture land were restored to usable condition within 10 years. Both species now tend to extreme mass changes because they can effectively defoliate their food plant over large areas of land, whereupon their own stock collapses due to lack of food. Due to the high heat requirement of both species, however, they were not very successful in combating in tree-shaded habitats. C. quadrigemina proved to be the more effective species overall and is far more common today, which is attributed to its development time a few weeks earlier. C. hyperici is involved in success in moister, somewhat cooler habitats, but is considered the less important species.

In addition to its target species Hypericum perforatum , Chrysolina hyperici also became host to Hypericum species native to the new regions . Under the new, tightened security conditions for the importation of foreign organisms, there would probably never have been a suspension.

Taxonomy

In addition to the nominate form, the subspecies Chrysolina hyperici daghestanica is also specified. According to a more recent study from 2013, Chrysomela daghestanica Reitter, but in 1912 actually a synonym of the species Chrysolina cuprea , the assignment to C. hyperici by J. Bechyné would have been erroneous.

Individual evidence

  1. ↑ a b c d e f Chrysolina hyperici (Forster, 1771) . UK Beetle Recording. Retrieved October 7, 2017.
  2. ↑ a b c d e genus Chrysolina # 25 . www.coleo-net.de. Retrieved October 7, 2017.
  3. ^ A b Gustav Adolf Lohse & Wilhelm H. Lucht: Die Käfer Mitteleuropas. 3. Supplementary volume with catalog section. Goecke & Evers, Krefeld 1994. ISBN 3-87263-045-8
  4. ↑ a b c d e f g Species Chrysolina hyperici - St. Johnswort Beetle . bugguide.net. Retrieved October 7, 2017.
  5. ^ Chrysolina (Hypericia) hyperici (Forster, 1771) . Fauna Europaea. Retrieved October 7, 2017.
  6. ↑ a b c St. John's Wort and Chrysolina spp. Beetles . Ontario Ministry of Agriculture, Food and Rural Affairs. Retrieved October 7, 2017.
  7. ↑ a b Chrysolina hyperici (Forster, 1771) (a leaf beetle) . www.bioinfo.org.uk. Retrieved October 7, 2017.
  8. ↑ DT Briese (1997): Biological control of St. John's word: past, present and future. Plant Protection Quarterly 12 (2): 73-80.
  9. ^ CAR Jackson & JH Myers (2008): Species pairs for the biological control of weeds: advantageous or unnecessary? Proceedings of the XII International Symposium on Biological Control of Weeds, La Grande Motte, France, April 22-27, 2007: 561-567.
  10. ↑ Ronny Groenteman, Simon V. Fowler Jon J. Sullivan (2010): Response of two species Chrysolina to different Hypericum hosts. Proceedings of the 17th Australasian Weeds Conference: 227-230.
  11. ↑ Ronny Groenteman, Simon V. Fowler Jon J. Sullivan (2011): St. John's wort beetles would not have been Introduced to New Zealand now: A retrospective host range test of New Zealand's most successful weed biocontrol agents. Biological Control 57 (1): 50-58. doi: 10.1016 / j.biocontrol.2011.01.005
  12. ^ Chrysolina hyperici (Förster, 1771) . www.biolib.cz. Retrieved October 7, 2017.
  13. ↑ AO Bieńkowski (2013): A Review of the Leaf-Beetle Genus Chrysolina Motschulsky (Coleoptera, Chrysomelidae) from Russia and European Countries of the Former USSR. III. Remarks on the Systematics and Distribution of the Species. Entomological Review 93 (4): 475-482. (orig. Entomologicheskoe Obozrenie 91 (3) 2012, 648–657.

Web links

Commons : Chrysolina hyperici  - collection of images, videos and audio files