''Cetonia aurata'', called the rose chafer or the green rose chafer, is a

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 ...

, long, that has a metallic structurally coloured green and a distinct V-shaped scutellum. The scutellum is the small V-shaped area between the wing cases; it may show several small, irregular, white lines and marks. The underside of the beetle has a coppery colour, and its upper side is sometimes bronze, copper, violet, blue/black, or grey. ''Cetonia aurata'' should not be confused with the North American rose chafer, ''

Macrodactylus subspinosus ''Macrodactylus subspinosus'' is a North American beetle of the family Scarabaeidae. The members of this genus are known as "Rose chafers", not to be confused with the European "Rose chafer", ''Cetonia aurata''. ''M. subspinosus'' occurs from E ...

'', or with the rarely seen noble chafer, ''Gnorimus nobilis'', which is very similar to the rose chafer. One way to identify ''Cetonia aurata'' is to look at its scutellum; on the noble chafer the scutellum is an

equilateral triangle In geometry, an equilateral triangle is a triangle in which all three sides have the same length. In the familiar Euclidean geometry, an equilateral triangle is also equiangular; that is, all three internal angles are also congruent to each oth ...

, but on the rose chafer it is an

isosceles triangle In geometry, an isosceles triangle () is a triangle that has two sides of equal length. Sometimes it is specified as having ''exactly'' two sides of equal length, and sometimes as having ''at least'' two sides of equal length, the latter versio ...

Overview

Rose chafers are capable of fast flight; they fly with their wing cases down. They feed on

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...

nectar Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualist ...

, and

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanis ...

s, especially

rose A rose is either a woody perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred species and tens of thousands of cultivars. They form a group of plants that can be ...

s. They can be found among roses on warm sunny days from May until June or July, and occasionally as late as September. Rose chafers are found in southern and central Europe and in the southern part of the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and ...

, where they sometimes seem to be very localized. They can also be found in South East Asia, in the countryside and outlying islands of

Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China (abbr. Hong Kong SAR or HKSAR), is a List of cities in China, city and Special administrative regions of China, special ...

. They are a beneficial

saprophagous Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi (f ...

species (

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrate ...

s).

Life cycle

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. ...

e are C–shaped and have a firm, wrinkled, hairy body, a small head, and tiny legs. The larvae overwinter wherever they have been feeding, which may be in

compost Compost is a mixture of ingredients used as plant fertilizer and to improve soil's physical, chemical and biological properties. It is commonly prepared by decomposing plant, food waste, recycling organic materials and manure. The resulting ...

manure Manure is organic matter that is used as organic fertilizer in agriculture. Most manure consists of animal feces; other sources include compost and green manure. Manures contribute to the Soil fertility, fertility of soil by adding organic ma ...

, leaf mould, or rotting wood. They grow very quickly and will have moulted twice before the end of autumn. They have a two-year life cycle. They

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...

te in June or July. Some adult beetles may emerge in autumn, but the main emergence is in spring, when the beetles mate. After mating, the female beetles lay their eggs in decaying organic matter and then die.

Coloration

The metallic green coloration of the beetle is created structurally, caused by the reflection of mostly

circularly polarised light In electrodynamics, circular polarization of an electromagnetic wave is a polarization state in which, at each point, the electromagnetic field of the wave has a constant magnitude and is rotating at a constant rate in a plane perpendicular to t ...

; like other scarabs this is left circularly polarised. When viewed through a right circular

polariser A polarizer or polariser is an optical filter that lets light waves of a specific polarization pass through while blocking light waves of other polarizations. It can filter a beam of light of undefined or mixed polarization into a beam of well- ...

, the beetle appears to be colorless. There are also different colors besides the common green; there is also copper, grey and black. A lot of specimens have white speckles while some have very few or none at all. It has been described as a left-hand narrow-band

elliptical polarizer In electrodynamics, elliptical polarization is the polarization of electromagnetic radiation such that the tip of the electric field vector describes an ellipse in any fixed plane intersecting, and normal to, the direction of propagation. An ellip ...

.Chirality-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson. 2012
/ref>

Gallery

Scara fg03.jpg, Larva Cetoine global.jpg, Pupa Cetonia aurata (Linnaeus 1761).jpg, Adult Cétoine dorée vol.jpg, With outspread wings; note the closed elytra Cetonia aurata take off composition 05172009.jpg, Flight pattern Cetonia aurata MF.jpg, Color variations Rose chafers (Cetonia aurata) on thistle (Carduus sp.).jpg, on thistle

References

External links