Asiatic ash splendor beetle

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Asiatic ash splendor beetle
Asiatic ash splendor beetle (Agrilus planipennis)

Asiatic ash splendor beetle ( Agrilus planipennis )

Systematics
Class : Insects (Insecta)
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Family : Jewel beetle (Buprestidae)
Genre : Agrilus
Type : Asiatic ash splendor beetle
Scientific name
Agrilus planipennis
Fairmaire , 1888
Agrilus planipennis from below
Agrilus planipennis mating
Pupae of Agrilus planipennis
Typical tunnels under the bark of the ash tree caused by larval damage
Red ash ( Fraxinus pennsylvanica ) dead due to infestation by the Asian jeweled ash beetle

The Asian ash borer ( Agrilus planipennis ) is a green-metallic colored beetles from the family of jewel beetles (Buprestidae). The species develops on ash trees . The beetle is native to eastern Asia (northeast China , Japan , South Korea , Taiwan , Mongolia ) and far-eastern Russia . Decades ago it was also introduced to North America, where it has established itself as an invasive species and poses a major threat to the ash population there.

features

The adults of A. planipennis have a dark green metallic shimmer, which is why the beetle got its English name emerald ash borer ("emerald green ash borer "). In appearance, the beetles are similar to the two-point oak splendor beetle ( Agrilus biguttatus ) native to Europe . The beetle has an elongated body that tapers conically towards the end and is about 13 millimeters long and 2.0 millimeters wide.

Way of life

The Asian ash splendor beetle colonizes both healthy and damaged trees. It predominantly prefers ash trees , but it can also be found on a few other tree species. The beetle was found on white ash ( Fraxinus americana ), Fraxinus chinensis , Fraxinus japonica , Fraxinus lanunginosa , Fraxinus mandshuriana , black ash ( Fraxinus nigra ), red ash ( Fraxinus pennsylvanica ) and Fraxinus rhynchophylvanica . He is also on Juglans mandshurica , Japanese wingnut ( Pterocarya rhoifolia ), and the elm species Ulmus davidiana and Ulmus propinqua .

The beetles hatch from the bark of the infested trees in spring and are mostly active on warm and sunny days. They only live about three to six weeks. In search of mating partners, they never move more than a maximum of 1 ½ km from their original tree. After mating, the female lays 60 to 90 eggs about one millimeter in size in the cracks of the ash bark. About two weeks after the eggs are laid, the larvae hatch and immediately begin to dig into the ash trunk. Larvae then create large tunnels under the bark.

After a year or two of development, the larvae reach a length of 26 to 32 millimeters and pupate in a small chamber. The beetles hatching from the pupae bore their way through the bark and the life cycle begins again.

Harmful effect

The affected trees deal with the infestation by the beetle in very different ways, depending on the species. While most of the East Asian tree species are only slightly damaged, the infestation has serious consequences on the ash species on the American continent, especially the white ash , black ash and red ash . As a rule, the tree dies after a few years due to the infestation. In the Asian ash species, the coexistence of beetles and trees, which has existed for thousands of years, has led to a partial resistance of the host trees, which prevents excessive reproduction of the beetles, the background of which is not yet fully understood. The American ash species only came into contact with the insect a few decades ago, so that there are no protective mechanisms here and the beetle can spread unchecked to damage the host tree.

The damage to the tree is caused by the larvae, the beetles themselves hardly cause any damage worth mentioning by eating their leaves. The larval ducts destroy the bast layer (the phloem ) and thus the vascular structure of the tree, which leads to the death of the tree sections higher up. This process typically takes two to four years, with the earliest externally visible sign being the death of the treetop.

The Asian ash splendor beetle as an invasive species

United States and Canada

In 2002, the Asian ash jewel beetle was first discovered as a pest on various ash species in the US state of Michigan . It is believed that the beetle was introduced from East Asia as early as the 1980s or 1990s, probably unintentionally through the use of ash wood as a packaging material. The beetle spread in Michigan's ash forests, where it has few natural enemies. It is estimated that around 50 million ash trees have perished from the beetle in the American Midwest . The states around the Great Lakes are particularly affected . For example, it is estimated that the state of Wisconsin has more than 770 million ash trees, making up about 7% of the total tree population.

In 2009, the Asian ash splendor beetle was detected in a total of 12 US states and two Canadian provinces. In response to the biological threat to the ash population, a comprehensive program to contain the spread of the beetle was launched and rules for the Emerald Ash Borer (EAB) quarantine were adopted .

The fact that the insect has spread so quickly over large areas, even though the beetles can only travel a short flight distance, has led to the assumption that the spread was inadvertently largely carried out by humans, through the transport of infested ash wood , e.g. B. in the form of firewood. Accordingly, legal regulations have been issued that prohibit the transport of wood from areas that are under EAB quarantine.

Russia

In September 2013, the report that the Asian ash jewel beetle was also found about 250 km west of Moscow caused a certain alarm mood. Scientists fear that the species will spread further west towards Central and Western Europe. The beetle has not yet been discovered in the ash populations there, but it is known that the European common ash ( Fraxinus excelsior ) can be seriously damaged by the beetle. This development is particularly worrying, as European ash stocks have been decimated for years by massive ash dieback caused by the Chalara fraxinea fungus , to which it is estimated that up to 90% of the ash stocks will fall victim. It is feared that the few European ash trees that prove to be resistant to Chalara fraxinea may then fall victim to Agrilus planipennis . The American and European ash trees could face a similar fate as the American chestnut ( Castanea dentata ) when the chestnut crustacean ( Cryphonectria parasitica ) appeared.

Combat

Various insecticides were used to prevent the spread of Agrilus planipennis . However, there are considerable ecological concerns about its use in large forest areas. There are also concepts for biological pest control. For example, Cerceris fumipennis , a species of digger wasp from the Crabronidae family that occurs naturally in North America and lays its eggs in the larvae of jewel beetles, is being discussed as a possible parasitoid of Agrilus planipennis .

Individual evidence

  1. ↑ a b c d Thomas Schröder: The Asian ash splendor beetle. (No longer available online.) Waldwissen.de, 2004, archived from the original on October 15, 2013 ; Retrieved October 15, 2013 .
  2. ↑ What does EAB Look Like? Wisconsin's Emerald Ash Borer Information Site, accessed October 15, 2013 .
  3. ^ Gould, July S .; Bauer, Leah S .; Lelito, Jonathan; Duan, Jian (May, 2013), Emerald Ash Borer Biological Control Release and Recovery Guidelines (PDF; 2.9 MB) , Riverdale, Maryland, USA: USDA-APHIS-ARS-FS, accessed August 28, 2013.
  4. ↑ a b Why is EAB important? Wisconsin's Emerald Ash Borer Information Site, accessed October 15, 2013 .
  5. ^ A b Cooperative Emerald Ash Borer Project. (PDF; 2.0 MB) October 1, 2013, accessed October 15, 2013 (map of the regions affected in the United States).
  6. ^ EAB locations in North America. (PDF; 3.2 MB) United States Department of Agriculture: Animal and Plant Health Inspection Service, accessed on September 1, 2013 (English).
  7. ^ State and Federal Quarantines. Wisconsin's Emerald Ash Borer Information Site, accessed October 15, 2013 .
  8. ^ Risk Assessment of the Movement of Firewood within the United States. (PDF; 3.4 MB) United States Department of Agriculture: Animal and Plant Health Inspection Service, accessed on October 15, 2013 .
  9. ↑ Moving Firewood. Wisconsin's Emerald Ash Borer Information Site, accessed October 15, 2013 .
  10. ↑ a b Ania Lichtarowicz: Ash trees also face insect threat. BBC News, September 26, 2013, accessed October 16, 2013 .
  11. ↑ Spiegel ( online )
  12. ^ Daniel A. Herms, Deborah G. McCullough, David R. Smitley, Clifford S. Sadof, R. Chris Williamson, Philip L. Nixon Borer: Insecticide Options for Protecting Ash Trees from Emerald Ash. (PDF; 382 kB) 2009, accessed on October 15, 2013 (English).
  13. ↑ Cerceris fumipennis - A Biosurveillance Tool for Emerald Ash Borer. (PDF; 2.4 MB) Canadian Food Inspection Agency, accessed on October 16, 2013 .
  14. ↑ Rupa Shenoy: Stingless wasps latest tool in fight against emerald ash borer. Minnesota Public Radio News, May 26, 2011, accessed October 16, 2013 .

Web links

Commons : Asiatic ash splendor beetle ( Agrilus planipennis )  - Collection of images, videos and audio files