Meadow foam cicada
| Meadow foam cicada | ||||||||||||
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Typical color morphs of the meadow foam cicada ( Philaenus spumarius f. Typica ) |
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| Scientific name | ||||||||||||
| Philaenus spumarius | ||||||||||||
| ( Linnaeus , 1758) |
The meadow cicada ( Philaenus spumarius ) is a round head cicada (Cicadomorpha, Clypeorrhyncha) within the family of the foam cicadas (Aphrophoridae). The species is one of the best known and most widespread representatives of this group of insects .
It is characterized by a very high degree of variability in drawing; about 20 different color morphs are known. Due to its extraordinary jumping ability, with which it even surpasses the flea (Siphonaptera), the adult insect is often mistaken for grasshoppers , with which the cicadas are not closely related. The outer shape is reminiscent of beetles (Coleoptera). the meadow foam cicada is easily recognizable as a cicada by its roof-like wing position. Most people are less familiar with their larvae than with their self-made foam shells known as “ cuckoo spit ”. This can usually be observed more often in the meadow foam herb on meadows in spring . The meadow-foam cicada has been able to adapt to diverse habitats in the course of evolution and is now distributed almost worldwide through numerous naturalizations.
etymology
There are several derivatives for the generic name " Philaenus ":
- the one who loves the speech (Greek phil -ainos);
- from philenor (Greek: in love);
- Name of a Carthaginian who allowed himself to be buried alive out of love for his country.
The species name " spumarius " is derived from the Latin " spuma " = "foam" and refers to the foam nests created by the larvae.
The so-called "cuckoo's saliva", also known locally as "witch's spit", is often found in meadows , often on meadow foam herb ( Cardamine pratensis ), which gave this plant its name. In Europe, the term “cuckoo saliva” is associated with the appearance of the cuckoo ( Cuculus canorus ) in spring, when the foam balls can be observed more frequently. In many places the meadow foam herb, the flower of the year 2006 , is therefore also called the “cuckoo flower”.
In English and French, the meadow-foam cicada is referred to as Meadow Spittlebug or Cercope des prés with reference to their main habitat. In Dutch it is called Spuugbeestje , which can be translated as “spit animal”.
Geographical distribution and habitats
With the exception of the Arctic and Antarctic, meadow-foam cicadas occur in all zoogeographical regions from lowlands to mountainous locations up to around 1800 m . Their original distribution was limited to the Palearctic . Europe is populated from Lapland to the Mediterranean area. It has also been detected in North Africa , parts of Russia , Afghanistan and Japan .
The meadow-foam cicada was introduced to North America and Canada , where it has established itself as a neozoon . The Azores , Hawaii and New Zealand in the southern hemisphere also belong to its range today , where it was also introduced over the past five decades. The most recent finds include Turkey in the range of the cicada.
Meadow-foam cicadas have been able to adapt to diverse habitats in the course of evolution. They are extremely eurytopic, which means that they occur in many different habitats. They live in almost all open land biotopes and in open forests.
Outer shape
The meadow foam cicada is usually inconspicuously straw-colored, brownish or black in color. It has various patterns with lighter spots on a dark background, darker drawings on a light background, or it is monochrome, dark or straw-colored. It is a standard example of intraspecific color and drawing polymorphism . There are more than 20 different colored shapes known, with numerous transitions between them. Many of the color morphs have their own name, such as Philaenus spumarius f. albomaculata , Philaenus spumarius f. leucophtalma or Philaenus spumarius f. lateralis .
The shape of the body is elongated and oval in outline, slightly wider than that of the representatives of the genus Neophilaenus - for example the grasshopper plant . The wing tips are not pointed at the bottom, but rather bluntly rounded - in contrast to the representatives of the genus Aphrophora, for example the Alpine foam cicada . The hairy wing covers are leathery and covered with point pits. Although often confused with beetles (Coleoptera), it is easily recognizable as a cicada by its roof-like wing position. The membranous hind wings lie under the forewings. The species reaches body lengths between 5.3 and 6.9 millimeters. Usually the females are slightly larger than the males.
The feet ( tarsi ) of the meadow foam cicada are tripartite. The rails of the rear pair of legs ( tibia ) are round and relatively short. The rails of the hind legs have two strong thorns and a wreath of thorns ( meron ) at the base, which give them good jumping power.
Seen from above, its head is as wide as the pronotum and has two point eyes ( ocelles ), a pair of compound eyes and a pair of short bristle-shaped antennae . In contrast to the closely related members of the genus Neophilaenus and Aphrophora, the forehead does not show a median longitudinal keel. The forehead plate ( clypeus ) (head part between the ocelles) is more or less vaulted in the form of bubbles when viewed from the front and the side and contains the suction pump. Like all cicadas, meadow-foam cicadas have a proboscis for feeding. The lower lip ( labium ) of the animals is designed as a slide for the spikes made up of the mandibles and maxillae . Inside the laciniae (part of the maxilla) there is a channel through which suction can take place, as well as a saliva channel through which saliva is conducted into the feeding site. In all Schnabelkerfen parts of the oral cavity are transformed into a suction pump.
Internal structure and physiology
The internal anatomy and physiology of the leafhoppers largely correspond to those of the insects. In adaptation to the special diet, meadow-foam cicadas, like all round-headed cicadas, have a special construction of the digestive tract in order to release excess water or carbohydrates . The very water-rich plant sap of the conduction pathways ( xylem ) is, in contrast to the sugar-rich phloem sap, significantly poorer in nutrients, which is why leafhoppers that only feed on it have to ingest a lot of them. In the intestines of the sap teats there is a filter chamber that creates a transition region between the fore and midgut and the hindgut. It allows the excess water to be drained directly into the rectum and the nutritional juice is thickened before it enters the midgut. Furthermore, the centers of the rope ladder nerve systems typical of insects are only present in the round-headed cicadas in the head and chest; the abdomen is supplied by the nerve center of the chest.
Way of life
The basis for the existence of a species is the longest possible survival of a sufficient number of individuals even under changing and unfavorable environmental conditions and high predation pressure (many predators). The success of the meadow-foam cicada lies primarily in its broad ecological potential , which means that it can withstand a wide range of environmental factors and thus exist in a wide variety of biotopes. It is believed that moisture levels are an important factor in the occurrence of the species. It is only absent in very wet and very dry biotopes. It is also absent in arctic , alpine and arid zones. The annual average temperature that is too low or too high is a limiting factor here. Furthermore, their host plant specificity is low, because they can feed on a variety of plants - in contrast to most species of cicada, which are often mono- or oligophagous . Over 170 nutrient plants were identified. It is these properties that enable this cicada to survive and reproduce here even after it has been introduced into other countries such as New Zealand. Furthermore, it uses its pronounced jumping ability to escape from enemies and to spread into new habitats. It survives unfavorable climatic periods in the form of eggs. A single female can produce up to 350 to 400 eggs. Your larvae are largely protected from predators in the foam balls. They also receive the humidity and temperature they need for further development, so that their mortality remains low even in bad weather.
Locomotion
The most common form of locomotion of the meadow foam cicadas is running and flying, but the most distinctive is jumping. The legs of the adult insects, unlike the sluggish larvae, give them good jumping power. The mighty thorns on their hind legs benefit them when jumping, as they give the jump legs support on the surface. Foam cicadas are even the world champions in high jump. The researcher Malcolm Burrows discovered this on high-speed photos. In relation to its own body length, no living being can jump as high as the meadow foam cicada. The insect is half a centimeter long and reaches a height of 70 centimeters from a standing position. Converted to our body size, humans would have to be able to jump about 200 meters high to catch up with the cicadas. In relation to her body size, she beats all other insects, including the previous record holder, the flea (Siphonaptera). It also blows four times faster. Only the rearmost pair provides jump energy. The meadow-foam cicada can build up tension in these legs like in a catapult and then discharge it. This type of locomotion is primarily used by the leafhoppers to escape.
nutrition
Most species of cicada are restricted to certain nutrient plants. The meadow-foam cicadas, on the other hand, are polyphagous , which means that they are not very particular about their food and use several plant species or families. Nutrient plants are mainly grasses (Poaceae), rushes (Juncaceae), herbs and sometimes also woody plants.
Sound production and senses
Meadow foam cicadas are able to produce rhythmic chants to help them find a partner. These are generated by special drum organs ( tymbal organs ) that are located on the sides of the first abdomen segment. By pulling a strong sing muscle, the membrane of the drum organs is set in vibration. The noise is generated by indenting (muscle pull) and jumping back (inherent elasticity). With the meadow foam cicadas, as with all types of subordination of the round head cicadas with the exception of the singing cicadas, the perception of acoustic stimuli (hearing) does not play a role (only the singing cicadas have auditory organs). Rather, they are equipped with receptors all over the body in order to perceive air currents, contact with other living beings or the parts of plants on which they sit. The vibrations transmitted from the drum organs to parts of plants are probably absorbed in this way as so-called substrate vibrations . The frequencies of the signals are mainly between 200 and 1000 Hertz ; they can only be heard by humans using technical means. The vibrations are very species-specific, so that pairings between similar and closely related species are prevented by “not understanding”. The females are mostly stationary and send out search calls, while the males run around searching and calling. When they find each other, a real alternating song can develop.
The orientation of the cicadas occurs through the absorption of environmental stimuli. Your compound eyes are able to recognize and differentiate shapes as well as colors. This enables them to notice pursuers, but also to target plants. They even seem to recognize the color of their nutrient plants and also to be able to judge the seat for hiding uniformity. In addition, meadow foam cicadas have so-called mechanoreceptors in almost all parts of the body to perceive contact stimuli such as air currents or contact with the substrate.
Reproduction and development
Mating and laying eggs
Mating is initiated by the male by anchoring his genital fittings to that of the female. It sits diagonally next to the female during the entire copulation and holds on to the side. This creates a V-position typical of leafhoppers and representatives of the Cicadoidea.
The females lay the eggs individually or in groups on the larvae 'nutrient plants. The eggs are about 1 millimeter long and 0.35 millimeters wide. They are oval, pointed in outline, yellowish white with an orange pigmented spot at one end. In the case of fertilized eggs, this spot on the egg shell (serosa) enlarges and a lid-shaped, black-pigmented device for tearing through the opening of which the larva hatches develops. After about 20 days, the larvae of the first larval stage leave the egg shell. This black spot will not develop on unfertilized or unhealthy eggs. The eggs will turn brown and shrivel.
Development of the larvae
Meadow leaf hoppers are hemimetabolic . They undergo an incomplete transformation from the egg via the larva directly (without the pupal stage) to the full insect ( imago ). The development of the larvae takes place over five stages, whereby with increasing age the facilities for the organs of the adult animal (wings, genital fittings) form and enlarge. The various stages merge into one another via molting. The larval stage lasts around 50 days. The initially green adult animals leave the foam nest to dry and color completely. This process takes about ten days. The females mate soon afterwards.
The back of the larvae is highly arched in a semicircular cross-section, the belly is concave. The head is strongly bulged in front of the antennae and eyes and overall round. In the first larval stage (L1), the orange-colored, very tender larva measures around 1.35 millimeters. The wings and genitals are not yet developed. In the second stage (L2) the body length of the animals reaches about 2.25 millimeters. Their color changes to a yellowish orange. In the third larval stage (L3), the larva grows to a body length of around 3 millimeters. It is now greenish-yellow and the wings are already visible. In the fourth stage (L4), the larva measures around 4.75 millimeters, it is now clearly green, the wings are clearly visible and yellow. In the fifth and last larval stage (L5) a body length of up to 6.25 millimeters is reached. Wing approaches and genital fittings are well and clearly developed.
The foam
The foam also protects the larvae sitting in it from enemies, but primarily receives the moisture and temperature necessary for further development. In the respiratory cavity of the larvae are the respiratory openings (stigmata), the confluence points of the trachea on the body surface. The trachea form a system of breathing tubes that runs through the entire body of an insect and is the functional equivalent of our lungs . The foam is generated by rhythmically pumping in air bubbles from the respiratory cavity into a protein-containing liquid, which the larvae secrete from the anus. This process continues until the imago leaves the excrement . The consistency of the foam can only be maintained because the animals excrete mucous substances from glycosaminoglycans (formerly mucopolysaccharides) and proteins from special excretory organs in the intestine ( Malpighian vessels ) . Studies have shown that the foam of the meadow leaf hoppers consists of 99.30% water. But it is so strong that it can withstand a rain shower undamaged.
Enemies and parasites
As herbivores, meadow-leavened leafhoppers are first-order consumers and thus take on an important role in the ecosystem of the natural environment. As a group of insects with a large number of individuals, they play an important role in the formation of complex food webs as food for other animals . However, extensive studies of their natural enemies are still largely lacking. However, individual works indicate numerous vertebrates , invertebrates and parasitoids that use both the adult animals, the larvae and the eggs.
It was based on the examination of the stomach contents and feces various bunting (Emberizidae) - evening bunting (Poocetes gramineus) , Klapper bunting (Spizella pusilla) , Chipping Sparrow (Spizella erina) found that their main food is the breeding season from meadowfoam cicadas -. Other birds (Aves) that feed on the adult insects are the capercaillie chicks ( Tetrao urogallus ), the partridge ( Perdix perdix ), the house martin ( Delichon urbicum ), the rook ( Corvus frugilegus ), the mistletoe ( Turdus viscivorus) ), the song thrush ( Turdus philomelos ) and the starling ( Sturnus vulgaris ). The capercaillie and the pheasant (Phasianus colchius) apparently also feed on the larvae. Furthermore, meadow-foam cicadas are apparently also the main component of the diet of the common frog ( Rana temporaria ).
In invertebrates, it is mainly spiders (Arachnida), hymenoptera (Hymenoptera), two-winged birds (Diptera) and beetles (Coleoptera) that act as predators. The Weberknecht -Art Mitopus morio feed on the eggs.
The ant Formica montana prey on larvae in North America.
Some hymenoptera of the genera Ooctunus , Tumidiscapus and Centrodora are known as parasitoids of the eggs. Adult cicadas are the cicadas wasp (Dryinidae) Verralia aucta attacked.
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literature
The information comes from the following literature:
- Selçuk Yurtserver: On the polymorphic Meadow Spittlebug, Philaenus spumarius (L.) (Homoptera: Cercopidae). Turk. J. Zool. 24 (2000) 447-459. PDF (100 KB) available online
- Reinhard Remane & Eckart Wachmann: Cicadas - get to know, observe . Naturbuch-Verlag, Augsburg 1993. ISBN 3-89440-044-7 .
Individual evidence
The following sources are cited for individual aspects:
- ↑ Nickel, Herbert: On the etymology of the cicada names of Central and Northern Europe. In: Acta Musei Moraviae, Scientiae biologicae (Brno) 98 (2): 273-315 (284), 2013.
- ↑ Robert Biedermann & Rolf Niedringhaus: The cicadas of Germany - identification tables for all species. Fründ, Scheeßel 2004, ISBN 3-00-012806-9
- ↑ Wilfried Westheide & Reinhard Rieger (eds.): Special Zoology, Part 1: Protozoa and invertebrates. Gustav Fischer Verlag, Stuttgart, Jena, New York, 1996. Pages 650–651
- ↑ Malcolm Burrows: Froghopper insects leap to new heights . In: Nature, vol. 424, p. 509 (July 31, 2003).
- ^ Jason R. Cryan: Molecular phylogeny of Cicadomorpha (Insecta: Hemiptera: Cicadoidea, Cercopoidea, and Membracoidea): adding evidence to controversy. Systematic Entomology 30 (4), Oct 2005, pp 563-574.
- ↑ Hubert Ziegler & Irmgard Ziegler: About the composition of the cicada foam. Journal of Comparative Physiology , Vol. 40, pp. 549-555, 1958
- ^ Gregg Hendersson, George D. Hoffman & Robert L. Jeanne (1990): Predation on Cercopids and material use of the spittle in aphid-tent construction by Prairie Ants. Psyche 97: 43-53. PDF
further reading
- Michel Boulard: Diversité des Auchénorhynques Cicadomorphes. Formes, couleurs et comportements (Diversité structurelle ou taxonomique. Diversité particulière aux Cicadidés). In: Denisia 4, S 171-214, 2002. ISBN 3-85474-077-8 .
- Federal Agency for Nature Conservation (Ed.): Red List of Endangered Animals in Germany. Landwirtschaftsverlag, Münster 1998, ISBN 3-89624-110-9 .
- Herbert Nickel: The leafhoppers and planthoppers of Germany (Hemiptera, Auchenorrhyncha): Patterns and strategies in a highly diverse group of phytophagous insects. Pensoft, Sofia and Moscow 2003, ISBN 954-642-169-3 .
