Menemerus semilimbatus

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Menemerus semilimbatus
Menemerus semilimbatus, female

Menemerus semilimbatus , female

Systematics
Class : Arachnids (arachnida)
Order : Spiders (Araneae)
Subordination : Real spiders (Araneomorphae)
Family : Jumping spiders (Salticidae)
Genre : Menemerus
Type : Menemerus semilimbatus
Scientific name
Menemerus semilimbatus
( Hahn , 1829)

Menemerus semilimbatus is a spider from the family of jumping spiders (Salticidae). The species, unmistakable due to its distinctive appearance, was originally Palearctic , i.e. distributed in the northern hemisphere of the Old World , but was also introduced in North America and some states in South America . It is thermophilic (heat-loving) and can therefore only be found in climatically suitable habitats, such as the Mediterranean region , where it is also found more frequently in settlement areas.

Menemerus semilimbatus is characterized by a hunting technique specially used for flies (see section " Hunting method for flies ").

features

male

The female of Menemerus semilimbatus reaches a body length of 6.5 to 8.4 millimeters and the male one of 5.1 to 7.4 millimeters, making the species a comparatively large jumping spider.

Like all species of the genus, this one also has a flattened body. The long legs of Menemerus semilimbatus , which are visually reminiscent of a funnel spider, are striking compared to other jumping spiders . However, the overall habitus of the species makes confusion with other spiders unlikely. Within the genus, the structure of their sex organs can also be used to differentiate.

Habit and coloring

Well camouflaged female on stony ground

The prosoma (front body) of Menemerus semilimbatus is colored black-brown and has a sharply set off white band on both flanks. The center of the prosoma has a white triangle pointing to the front and an adjacent, indistinct and light longitudinal band at the back. The legs of the species have a light brown basic color and are decorated with light and dark spots.

The color of the opisthosoma (abdomen) does not differ from those of the legs. The dorsal side of the opisthosoma is, however, also provided with several bright V-shaped signs and yellowish spots

The habit of Menemerus semilimbatus seems to vary, however, by geographical location, so have copies of those on the Greek Dodecanese -Insel Kos found a significantly denser hair, which makes the opisthosoma appear almost white and almost disappearing species-specific pattern. This phenomenon does not occur in other areas of the Mediterranean.

Sexual dimorphism

The female can be distinguished from the male by the more reddish face and the completely white haired pedipalps .

Like many spiders, Menemerus semilimbatus also shows a pronounced sexual dimorphism (difference between the sexes), which is only recognizable here, however, in the front part of the prosoma. The male's face is darker in color than the rest of the prosoma. The pedipalps (transformed extremities in the head area) have snow-white hairy patellae (middle limbs) and tibiae (greaves). The female's face is more reddish in color and his pedipalps, unlike those of the male, are entirely covered with white hair.

Structure of the sexual organs

Male with clearly visible bulbi

The bulbi (male genital organs) have retrolateral tibia apophyses ( chitinized processes ) on the emboli ( organs of transmission). The embolus of a single bulb is closely connected to the sperm conductor, so that both structures together have a forceps-like appearance. In addition, the embolus has a small spine on the ventral side near the tibial apophysis. At the base of the femora (thighs) of the pedipalps (transformed extremities in the head area) there is an appendage in the male.

The rounded epigyne (female sexual organ) has a notch on the rear edge and two oval depressions in the front half, which lead to the copulation openings, which are covered with heavily sclerotized (hardened) anteromedial hoods. A pocket is formed near the epigastric (near the digestive tract) furrow.

Occurrence

Male in the municipality of Jimena de la Frontera in the province of Cadiz (autonomous community of Andalusia in southern Spain )

Menemerus semilimbatus is distributed in the Canary Islands , in the Mediterranean area with the exception of Algeria , parts of Eastern Europe , north to Belarus and in the Balkans to Romania . Evidence is missing from Bosnia and Herzegovina and Albania . In the small and central Asian region, this spider is widespread in Turkey , the Caucasus (east to Azerbaijan ) and Iran . In addition, the species was introduced in Argentina , Chile, and the state of California in the United States . The species, which is about to spread, will probably also be found in suitable habitats in Central Europe in the future because of the favorable climate change .

Habitats

In the wild, rocky habitats like these in the Sierra de las Moreras nature reserve in the Murcia region in southeastern Spain are inhabited by Menemerus semilimbatus .

Menemerus semilimbatus predominantly inhabits dry, sunny and rocky habitats , including the rocks of dried up stream valleys. The species also shows a pronounced synanthropy (preference for human settlements) and is often found on sunny house walls or inside buildings. Menemerus semilimbatus also lives in plantations and other habitats that are strongly influenced by humans, for example in citrus groves .

Threat and protection

Menemerus semilimbatus is often represented in the Mediterranean area. Also due to the adaptability to human settlement areas, where the species can occur very frequently, endangerments are unlikely. The general population of Menemerus semilimbatus is not rated by the IUCN .

Way of life

Purifying female

Like all jumping spiders , Menemerus semilimbatus is diurnal and especially active in sunshine, where the spider then runs around at great speed on rocks and walls. Like all jumping spiders, she spends the night in a web sack .

Hunting behavior and catch of prey

Like almost all spiders, Menemerus semilimbatus lives predatory and the hunting behavior of the species largely corresponds to that of other jumping spiders. No safety nets are made, but the prey animals are hunted freely. However, unlike many other jumping spiders, the species uses different prey capture strategies depending on the prey.

Loot spectrum

Female with captured sex animal of an ant

Due to the effective method of catching prey, Menemerus semilimbatus, like other jumping spiders, has a wide range of prey consisting of other arthropods . However, due to the preferred rocky and synanthropic habitats, which are relatively poor in species, the selection of suitable prey for Menemerus semilimbatus is rather small, so that flies and other spiders make up their main food. The size of the prey animal can be a maximum of one and a half times the size of the spider, but prey animals that are smaller or identical in size to the spider are preferred.

The spiders captured by Menemerus semilimbatus are mostly those that also prefer stony habitats, including other jumping spiders such as the golden-eyed jumping spider ( Philaeus crycrops ) or Salticus mutabilis . Menemerus semilimbatus avoids spiders or their nets in fishing nets . However, these species can also fall prey if they are not in their fishing nets. These include roaming juveniles or male specimens of these spiders that seek out the webs of females. The killing of such spiders has been demonstrated using juvenile females of the black-tipped ball spider ( Theridion melanurum ) and a roaming male of Filistata insidiatrix , which were captured by Menemerus semilimbatus .

Occasionally ants of the genus Crematogaster and Menemerus semilimbatus come together . The ants' workers are avoided by the spider, but the capture of winged sex animals has been proven. On occasion, dead arthropods are also accepted as food if they have not already dried out. Identifiable by Menemerus semilimbatus captured insects include, in addition to the order of the Diptera (such as flies) and the Hymenoptera which the (ex. The ants) butterflies , the thrips , the mayflies and the group of homoptera on. Also include springtails to prey spectrum of Art.

Hunting with prey that can be easily hunted down

Focusing female. A similar behavior can also be noted in the hunting mode of Menemerus semilimbatus .

Like all jumping spiders, Menemerus semilimbatus uses the well-developed, forward-facing eyes to visually perceive prey, which can be made out from a distance of up to one meter. If a prey has been sighted by the spider, it will approach it directly and with decreasing speed. A few centimeters away from the prey, the spider then pauses briefly and attaches the security thread common for jumping spiders to the ground. Then the hunter jumps directly at the prey and gives it a poisonous bite using the chelicerae (jaw claws) . The immobile prey is then consumed by the spider.

How to hunt flies

Male with captured fly

When hunting flies , Menemerus semilimbatus extends this trapping strategy . So the spider stops chasing the fly at a much greater distance. All further processes depend on the position of the fly in relation to the spider.

If the fly is facing the spider with its abdomen (abdomen), it performs the jump attack already explained above. If, on the other hand, the fly is facing the spider frontally or laterally, it circles the targeted prey until its abdomen is again the body segment closest to the spider. Once this is done, the spider tries to approach the fly from behind. However, if the fly changes its posture to a position that is unfavorable for the spider, it will shrink and start circling and creeping up to the fly again. The jump attack occurs as soon as the fly comes within range of the spider in a favorable position.

The hunting behavior of Menemerus semilimbatus in flies is broken down into the five phases of perceiving and locating the prey, approaching from a distance, circling when the prey is in an unfavorable position, approaching the prey directly, and finally jumping. A major difference in addition to the second phase of initial approach, which has been modified for flies and which the spider completes when chasing flies from a greater distance, is the third phase, circling in flies, which Menemerus semilimbatus does not use in other prey.

Life cycle

The ecology of Menemerus semilimbatus has hardly been researched to this day, which also includes the life cycle of the species including periods of activity and reproduction in the various regions. It is known that adult specimens can be found in Europe in spring and summer.

Systematics

The species Menemerus semilimbatus received the name Attus semilimbatus when it was first described in 1829 by the German arachnologist Carl Wilhelm Hahn . Based on the species name semilimbatus , Hahn called the spider in German "half-edged jumping spider", which indicates the well-defined white edges on both sides of the prosoma. The type specimen comes from the area around Naples. The genus Attus , which belongs to the jumping spiders, was referred to as "jumping spiders" by Carl Wilhelm Hahn, who lives in Bavaria. By Eugène Simon she was then in 1871 of the type described by him in 1868 Menemerus assigned and received their applied today scientific name Menemerus semilimbatus .

gallery

  • Dorsal view of a female

  • Frontal view of a female

  • Lateral view of a female

  • Rear view of a female

  • Detail view of a female

  • Dorsal view of a male

  • Frontal view of a male

  • Lateral view of a male

  • Rear view of a male

  • Detail view of a male

Individual evidence

  1. ↑ a b c d Menemerus semilimbatus (Hahn, 1829) from araneae - Spiders of Europe, accessed on July 17, 2020.
  2. ↑ a b c d A. Taucare-Rios, GB Edwards: First records of the jumping spider Menemerus semilimbatus (Araneae: Salticidae) in Chile , Peckhamia 102.1, 2012, pp. 1-3, accessed on July 17, 2020.
  3. ↑ a b c d e f g h Heiko Bellmann: The cosmos spider guide. Over 400 species in Europe. Kosmos Naturführer, Kosmos (Franckh-Kosmos), 2nd edition, 2016, p. 425, ISBN 978-3-440-14895-2 .
  4. ↑ a b c d Wanda Wesołowska: A revision of the spider genus Menemerus in Africa (Araneae: Salticidae) , Genus, Volume 10 (2), 1999, pp. 251–353, accessed on July 17, 2020.
  5. ↑ Michael Schäfer: On the jumping spider fauna (Araneae, Salticidae) of the Greek Dodecanese island of Kos, with twelve initial records, Arachnologische Mitteilungen, Volume 51, 2016, pp. 73-79, accessed on July 17, 2020.
  6. ↑ a b c Menemerus semilimbatus (Hahn, 1829) from Naturspaziergang, accessed on July 17, 2020.
  7. ↑ Menemerus semilimbatus (Hahn, 1829) at Global Biodiversity Information Facility , accessed on 17 July 2020th
  8. ↑ a b c d e f g h D. V. Logunov & D. Penney: Natural prey of the jumping spider Menemerus semilimbatus (Hahn, 1827) (Araneae: Salticidae), with notes on its unusual predatory behavior , European Arachnology 2003, p. 93 –100, accessed July 17, 2020.
  9. ^ Carl Wilhelm Hahn : Monographia Aranearum = monograph of the spiders. Fifth volume, plate III, Lechner, Nuremberg 1829 (first description)
  10. ^ Eugène Simon : Monograph des espèces européennes de la famille des attides (Attidae Sundewall. - Saltigradae Latreille) . Annales de la Société Entomologique de France, 4, 8, pp. 11-72 and 529-726, 1868, p. 662.
  11. ↑ Menemerus semilimbatus (Hahn, 1829) in the WSC World Spider Catalog , accessed on 17 July 2020th

literature

Web links

Commons : Menemerus semilimbatus  - collection of images, videos and audio files