Bronze green rose chafer

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Bronze green rose chafer
Bronze green rose beetle on bleeding oak

Bronze green rose beetle on bleeding oak

Systematics
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Family : Scarab beetle (Scarabaeidae)
Subfamily : Rose chafer (Cetoniinae)
Genre : Protaetia
Type : Bronze green rose chafer
Scientific name
Protaetia lugubris
( Autumn , 1786)
Protaetia lugubris side.JPG Protaetia lugubris detail.JPG
Fig. 1:
Side view of the subhumeral incision
Fig. 2: Mesosternal process from
obliquely below, left corresponds to the front
Protaetia lugubris front.JPG
Liocola lugubris under.jpg
Fig. 3: oblique view from the front Fig. 4: underside
Liocola lugubris dead.jpg
Liocola lugubris detail.jpg
Fig. 5:
Specimen found dead with only partially unfolded
wings
Fig. 6: Front end of the lateral
edge of the pronotum
(left eye)

The bronze green rose beetle , also marbled rose beetle , ( Protaetia lugubris (autumn 1786), syn .: Liocola lugubris , Protaetia marmorata (Fabricius, 1792)) is a beetle from the scarab beetle family (Scarabaeidae) and the subfamily rose beetle (Cetoniinae). The genus Protaetia is represented in Europe by five subgenus, the bronze-green rose beetle belongs to the subgenus Liocola . The beetle is listed in the Red List of Endangered Animals in Germany under Category 2 (“Endangered”), as is North Rhine-Westphalia and Bavaria . In Saxony , Thuringia and Brandenburg , the species is classified as endangered. In Schleswig-Holstein it is considered lost or extinct.

The species name lūgubris ( Latin for “mourning, gloomy”), like the German part of the name “bronze green”, refers to the basic color of the beetle, which is usually darker than that of the more common gold-shining rose beetle . The part of the name “marbled” is the translation of Latin “marmorata” and describes the white drawing. The beetle is only found in roses in exceptional cases.

Characteristics of the beetle

The broad and slightly domed, plump beetle (Fig. 1) is 19 to 25 millimeters in length and is significantly larger than the shiny gold rose beetle. The color-variable species (a two-tone individual was also described in 1988) is bald and shiny on the upper side. The beetle is mostly ore-brown with a very variable pattern of white spots that have the shape of speckles on the wing covers. The breastplate, the matt pygidium and the shiny belly are also spotted white.

The head (Fig. 3) is uneven, strong and not very densely punctured . Viewed from above, the square head shield conceals the mouthparts and appears to be cut off in front. Its front edge is raised evenly over the entire width, not more on the sides than in the middle (Fig. 3). The ten-segment antennae end in a three-leaved antenna lobe. The deflection of the sensors can be seen from above.

The pronotum is only very finely dotted in the central area, the points become denser and stronger towards the sides and can be wrinkled. The marginal ridges of the pronotum run out towards the front and do not reach the front corners (Figs. 3 and 6). This is an important determinant. The rear edge of the pronotum is clearly indented in front of the label (scutellar section). The scutellar section is angularly limited to the side, next to it the base is not booked again.

The elytra are strongly indented behind the shoulders (subhumeral incision, Fig. 1). There are few dots around the label, behind them the dots are in the shape of small horseshoes, the dots are wrinkled to the sides and towards the back. As with all rose beetles, the wing covers are not folded forward when flying, but remain closed (Fig. 5). The triangular label is broadly rounded at the top and arched outward at the base.

The front rails are designed as grave legs, especially in females. They are widened and reinforced with three teeth on the outer edge towards the tip. Cross bars are missing on the rear rails.

The mid-chest is enlarged forward (mesosternal process, Fig. 3). The mesosternal process is not spherical, but flat and wider than it is long. Towards the base it is clearly constricted between the mid-hips (Fig. 4). It is almost completely smooth and hairless. The rear hips are touching (Fig. 4). The abdomen of the males shows a median longitudinal furrow on the underside and is scattered very finely dotted. In the female the puncture is denser and stronger. The pygidium does not show any elongated impressions in the female either.

Egg and larva

The white eggs are only slightly oval with a diameter of about one and a half millimeters. The larva resembles a grub . The brown head is partially retracted into the first chest section. The hairy upper lip is three-lobed. The black upper jaws are curved. The two branches of the lower jaw have grown together almost to the top. The jaw probes are four-part, the lip probes are three-part with a very small basal phalanx. The first breast segment bears a brown chitin plate on each side above the foremost of the nine pairs of spiracles.

biology

The larva of the warmth-loving species develops in tree hollows in the silt of old deciduous trees , preferably in oaks and fruit trees. Common colonization of caves with the Russian beetle ( Osmoderma eremita ) has been observed.

An examination of trees on country roads in northern Poland found that out of around 4,000 trees inspected, a quarter had tree hollows suitable for breeding. Of these 1004 trees belonging to nine species, the caves of 74 trees belonging to seven species were inhabited by the bronze green rose beetle. A preference for certain tree species could not be determined, and the direction, size and height of the cave entrance were also unimportant for the choice. However, only trees with a trunk circumference of over 200 cm were inhabited and trunks with a circumference of over 300 cm were preferred.

The beetle can be found at the edges of the forest, in forest clearings and in parks, orchards and avenues, mainly on tree sap that is flowing out, occasionally in tree hollows, on blossoms or ripe fruits. In Central Europe the beetles can be found all year round, but mostly only from May to October with a maximum in July. They are diurnal and, in warm weather, brisk from morning to late afternoon.

When breeding the beetle, the oviposition follows the winter dormancy and extends over a period of fifteen to fifty days. The females can mate several times. In five observations, between 16 and 42 eggs were deposited in very moist gauze. In nature, the number of larvae found depends on the size of the cave. Less than fifteen larvae of the same stage are usually found in a tree cavity. At a constant temperature of 22 ° C, the larvae of the first stage hatch after 17 to 23 days. They are about four millimeters long and immediately active. They eat the egg shell first and then the moist gauze, while crawling on their belly. After 22 to 26 days they molt to the second stage. The larvae of the second instar overwinter in nature and, at low temperatures, enter a diapause between November and February . The third larval stage reaches a length of more than 60 millimeters and usually pupates in July / August, and in June if the temperature is high enough.

For pupation, the larva uses oral secretions to glue its own excrement with components of the gauze and other waste particles to form a pupa cradle that is smooth inside. This is where prenymphosis takes place, in which the digestive tract is emptied, the end of the abdomen is remodeled and the legs lose their function. A few days later the pupa hatches. In breeding, the pupal stage lasts 27 to 30 days. After molting, the beetle still needs five to six days to color. The adults do not reproduce until the following spring. They live for less than a year.

distribution

The distribution area extends from the east across Central Europe to northern Spain. In Italy too, only the northern part is reached. In northern Europe, however, the beetle's occurrence is limited to the southern parts. The species is absent in Portugal, the British Isles, Greece and the neighboring countries. In France, the range is incoherent and the beetle's occurrence is limited to heights between 0 and 550 meters. The species is distributed to the east with the subspecies Protaetia lugubris orientalis across Asia to the Sea of ​​Japan.

literature

Individual evidence

  1. a b Protaetia lugubris in Fauna Europaea. Retrieved October 31, 2012
  2. Protaetia in Fauna Europaea. Retrieved October 31, 2012
  3. Red Lists of Bionetworx
  4. Sigmund Schenkling: Explanation of the scientific beetle names (species)
  5. Devecis, Tauzin: Contribution à la connaissance of Cetoniinae de France: Iconographie de quelques variations chromatiques Spectaculaires. (Coleoptera, Scarabaeoidea, Cetoniidae) Cetoniimania 1 + 2 - June 2008 as PDF
  6. a b c d Pierre Tauzin: Ethologie et chorologie de Protaetia (Liocola) lugubris autumn 1786 en France Cetoniimania 1 + 2 - June 2006 as PDF
  7. A. Oleksa, W. Ulrich, R. Gawroński: Occurrence of the marbled rose-chafer (Protaetia lugubris Herbst, Coleoptera, Cetoniidae) in rural avenues in northern Poland Journal of Insect Conservation 10, pp. 241–247 doi: 10.1007 / s10841-005-4830-1 as PDF

Web links

Commons : Protaetia lugubris , Bronze Green Rose Beetle  - Album with pictures, videos and audio files