Large bladder beetle
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Large bladder beetle ( Malachius aeneus ), female |
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| Malachius aeneus | ||||||||||||
| ( Linnaeus , 1758) |
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Fig. 1: Front view (female) |
Fig. 2: Double hair (at the beginning of the wing cover crash) |
The large bladder beetle ( Malachius aeneus ) is a beetle from the subfamily of the tip beetle (Malachiinae) within the Melyridae . The genus Malachius is represented by 18 species in Europe . Their differentiation is made more difficult by the fact that the color varies greatly and that males and females have to be determined separately. So-called excitators are used to initiate sexual contacts, which are located on the forehead of the large bladder beetle.
The scientific name of the genus Malachius from Altgr. μαλάχιον "maláchion" means "mollusc". It refers to the only slightly sclerotized exoskeleton of the beetle. The species name aëneus ( Latin ) means "ore-colored". The German part of the name bladder beetle is used for two groups of species. The species in the oil beetle family (Meloidae) are also called blister beetles because touching the skin can cause blistering. The species of the genus Malachius are called bladder beetles because the males can protrude parts of the abdomen like blisters. The part of the name “large” is justified by the fact that the small beetle is larger than similar related species.
Characteristics of the beetle
The basic color of the flat, soft beetle is ore-green, but the red tips or edges of individual body parts are so extensive, especially on the wing covers , that the red color predominates. With a length of six to seven millimeters, the large bladder beetle is the largest Central European species of the genus. The hair on the body consists on the one hand of light, short, slightly lying, and on the other hand of long, dark and protruding hairs (double hairs, Fig. 2). The excitators - chitin structures in males that are important for the determination - lie on the forehead.
The head is green, yellowish in front of the antennae. The eleven-part antennae are pivoted between the eyes. In the female, the second antennae is unusually large, longer than half the length of the first antennae. In the male, only the second and third antennae are expanded inward. The extension of the second link has the shape of a sharp tooth pointing forward, the extension of the third link forms a thin hook bent backwards (picture under web links). The tip of the hook is further in than the tip of the tooth. The formation of the forehead in the male plays a role in mating behavior. Compared to the females, the forehead of the male is enlarged mainly in the longitudinal direction by reducing the post clypeus . It is extended to the front in a median ridge, on each of which there is a simple round depression, without edges or bulges. In the area of the probe deflection there is a secretion field that secretes certain substances for the female's jaw probe. At the front inner edge of the depression there is a field, the excretions of which act on the female's lip probe . To the front, the forehead region is bounded by a steeply erect convex wall, which begins far before the mandible deflection. This structure of the male forehead is called the head pit excitator. Excitators occur on different parts of the body in the different species of the genus.
The pronotum is wider than it is long, slightly wider than the head and about as wide as the elytra together between the shoulders. It does not narrow towards the rear, but is disc-shaped and, when viewed from above, it is strongly rounded at the rear corners and less rounded at the red front corners. Buckle-shaped red skin blisters can appear under the front corners.
The sides of the wing covers are straight, the wing covers widen slightly towards the rear. At the top they are very broadly rounded and leave the last abdominal segments uncovered. In the female, at least the sides, in the male, the tip and sides are scarlet red. In both sexes, the red color is usually much more extensive than the green color. The transition between red and green is blurred. The base of the wing covers with the shoulders and a backward extinguishing strip along the wing cover seam usually remain green.
The legs are narrow, the tarsi are five-limbed.
Eggs, larvae, pupa
The pale yellow eggs are oblong-oval with a longitudinal diameter of about 1.6 millimeters and a transverse diameter of half a millimeter. The surface appears without structure under the binocular.
The larvae have six functional legs. The abdomen ends in paired appendages, the urogomphi .
The dolls are among the free dolls .
biology
The adults appear for a relatively short time in spring, but long-lived females can still be found until September. In Central Europe, the animals are found in lower and higher altitudes, in Spain on mountain meadows. The heat-loving animals eat pollen from various grasses and are mainly found on meadows and on the edges of forests in warm locations. According to other observations, the adults are also predatory and only eat their pollen during the flowering period of the grasses. Females are usually much more common than males.
The larvae are omnivorous . They feed on detritus, mushrooms, pollen and small arthropods. Since the larva of the beetle also eats larvae of the rapeseed beetle ( Brassicogethes aeneus ), "it gains a certain value for the farmer" (quote from Brehm's Tierleben). In the Kursk district in the European part of Russia, the following data were obtained. The species overwinters as a larva. Dolls can be found from the end of the first third of May to the end of June. The first adults appear in early June. The oviposition can be observed from the third third of June and continues until mid-July. The very agile larvae molt twice and overwinter in the third larval stage. They noticeably decimate aphids and thrips larvae on summer cereals . The resulting benefits outweigh the damage caused by gnawing the grain blossoms.
In preparation for mating, the females bite into the distal extension of the forehead region of the males, with their lip and jaw probes in the area of the corresponding secretion fields in the pits of the excitator.
distribution
The species is widespread in Europe and Asia (Asia Minor, Caucasus, Persia, Siberia). The beetle was first registered in North America in 1852 and in Nova Scotia in 1922 . The species is widespread in North America today. In Germany the species was common in the east, but became increasingly rare and has disappeared in places, in the west the species has always only occurred in places and seldom, at most more frequently in warm regions.
literature
- Heinz Joy, Karl Wilhelm Harde, Gustav Adolf Lohse: The beetles of Central Europe . tape 6 : Diversicornia . Spectrum, Heidelberg 1979, ISBN 3-87263-027-X .
Individual evidence
- ↑ Malachius aeneus in Fauna Europaea. Retrieved September 3, 2012
- ↑ Malachius at Fauna Europaea. Retrieved September 3, 2012
- ↑ Sigmund Schenkling: Explanation of the scientific beetle names (genera)
- ↑ Sigmund Schenkling: Explanation of the scientific beetle names (species)
- ↑ a b c Dieter Matthes: Excitators and mating behavior of Central European Malachids (Coleopt., Malacodermata) Z.Morph.Ökol.Tiere 51, 375-546 (1962)
- ↑ a b c d e В. G. Shurovenkov: Entomophagous Melyridae (Coleoptera) in the fields in Kursk District, their Biology and Significance Revue d'Entomologie de l'URSS ЭНТОМОЛОГИЧЕСKОЕ ОBОЗРЕНИЕ, LIX; 3, pp. 535-543, 1980
- ↑ P. Bahillo de la Puebla, JI López-Colón: La familie Malachiidae Fleming 1821 en la Comunidad Autónoma Basca (Coleoptera: Cleroidea) Heteropterus Ref. Entomol. 2009, 9 (1) pp. 25–42, ISSN 1579-0681 as PDF ( memento of the original from January 7, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Klaus Koch : Die Käfer Mitteleuropas Ökologie . 1st edition. tape 2 . Goecke & Evers, Krefeld 1989, ISBN 3-87263-040-7 .
- ↑ Brehm's Thierleben. General knowledge of the animal kingdom, ninth volume, fourth division: Invertebrate animals, first volume: The insects, millipedes and spiders Leipzig: Verlag des Bibliographisches Institut, 1884, p. 112.
- ↑ Christopher G. Majka: New records of Melyridae (Coleoptera) of the Maritime Provinces of Canada Can. Entomol. 137: 325-327 (2005) as PDF
- ^ Adolf Horion : Faunistics of the Central European Beetles, Vol. 3: Malacodermata, Stenoxia Munich: Frey 1953
