''Agrilus biguttatus'' is a species of

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

in the family Buprestidae, the jewel beetles. Common names include oak splendour beetle, oak buprestid beetle, and two-spotted oak borer.Oak splendor beetle, ''Agrilus biguttatus''.
Invasive Species Fact Sheets. Michigan State University. February 2010. It is native to

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

, and

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a ...

.Ciesla, W
''Agrilus biguttatus''.
State and Private Forestry National Information Portal. US Forest Service. June 23, 2003. This beetle is known as a pest that causes damage to

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

trees and is a factor in oak decline. The adult beetle is 8 to 13 millimeters long. It is metallic green in color with a black or yellow cast.Domingue, M. J., et al. (2011)
Field observations of visual attraction of three European oak buprestid beetles toward conspecific and heterospecific models.
''Entomologia Experimentalis et Applicata'' 140(2), 112–21. There is a pair of white spots on the inner edges of the

elytra An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alterna ...

. The

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

is a creamy white color and measures up to 43 millimeters in length. The first thoracic segment is enlarged. The grub is legless and has a pair of horns on its last abdominal segment. Female beetles have an average lifespan of 2 months, but some may live upwards of 5 months.Reed, K., Denman, S., Leather, S. R., Forster, J., & Inward, D. J. G. (2018)
The lifecycle of Agrilus biguttatus: the role of temperature in its development and distribution, and implications for Acute Oak Decline.
Agricultural & Forest Entomology, 20(3), 334–346. The main hosts of this insect are oak species, including

English oak ''Quercus robur'', commonly known as common oak, pedunculate oak, European oak or English oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native plant, native to most of Europe west of the Caucasus ...

(''Quercus robur''),

sessile oak ''Quercus petraea'', commonly known as the sessile oak, Cornish oak, Irish Oak or durmast oak, is a species of oak tree native to most of Europe and into Anatolia and Iran. The sessile oak is the national tree of Ireland, and an unofficial embl ...

(''Q. petraea''),

downy oak ''Quercus pubescens'', the downy oak or pubescent oak, is a species of white oak (genus ''Quercus'' sect. ''Quercus'') native to southern Europe and southwest Asia, from northern Spain (Pyrenees) east to the Crimea and the Caucasus. It is also fou ...

(''Q. pubescens''),

evergreen oak Live oak or evergreen oak is any of a number of oaks in several different sections of the genus ''Quercus'' that share the characteristic of evergreen foliage. These oaks are not more closely related to each other than they are to other oaks. ...

(''Q. ilex''),

cork oak ''Quercus suber'', commonly called the cork oak, is a medium-sized, evergreen oak tree in the section ''Quercus'' sect. ''Cerris''. It is the primary source of cork for wine bottle stoppers and other uses, such as cork flooring and as the core ...

(''Q. suber'') and

turkey oak Turkey oak is a common name for several species of oaks and may refer to: *''Quercus cerris'', native to southeastern Europe and Asia Minor *''Quercus laevis ''Quercus laevis'', the turkey oak, is a member of the red oak group of oaks. It is n ...

(''Q. cerris''). The beetle can also be found on

European beech ''Fagus sylvatica'', the European beech or common beech is a deciduous tree belonging to the beech family Fagaceae. Description ''Fagus sylvatica'' is a large tree, capable of reaching heights of up to tall and trunk diameter, though more ...

(''Fagus sylvatica'') and chestnut (''Castanea sativa''). The beetle develops under the bark of the tree and produces damage to the wood during pupation. The female lays clusters of eggs in cracks in the bark and the larvae feed on the inner bark and outermost layer of wood. They produce long, zig-zag galleries in the tissues of the tree as they dig. This action causes

girdling Girdling, also called ring-barking, is the complete removal of the bark (consisting of cork cambium or "phellogen", phloem, cambium and sometimes going into the xylem) from around the entire circumference of either a branch or trunk of a woody ...

of the tree, preventing the circulation of nutrients through its tissues. The following spring, the adults emerge through holes in the bark and feed on the leaves of the tree. This species typically attacks trees that are previously stressed by insect damage, frost, or drought. It kills trees by the girdling action of the larvae. It contributes to oak dieback, large-scale losses of stands of oak trees caused by several factors. The beetle favors mature oaks with trunks over 30 centimeters in diameter. The adult beetle can fly several kilometers. It can also be transported to new areas with shipments of wood. Natural enemies of the beetle include

woodpecker Woodpeckers are part of the bird family Picidae, which also includes the piculets, wrynecks, and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar, and the extreme polar regions. ...

s, which dig the larvae from the bark. A number of

parasitoid wasp Parasitoid wasps are a large group of hymenopteran superfamilies, with all but the wood wasps (Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, sooner or later causin ...

s utilize the larvae, including '' Spathius curvicaudus'', '' S. ligniarius'', '' S. radzayanus'', '' Atanycolus neesii'',Moraal, L. G. & Hilszczanski, J. (2000)
The oak buprestid beetle, ''Agrilus biguttatus'' (F.) (Col., Buprestidae), a recent factor in oak decline in Europe.
''Anzeiger für Schädlingskunde'' 73(5), 134–38. and '' Deuteroxorides elevator''.Brown, N., et al. (2015)
A review of ''Agrilus biguttatus'' in UK forests and its relationship with acute oak decline.
''Forestry'' 88(1), 53–63.

References

Further reading