Cyrtophora citricola
| Cyrtophora citricola | |
|---|---|
| |
| C. citricola from Portugal | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Class: | Arachnida |
| Order: | Araneae |
| Infraorder: | Araneomorphae |
| Family: | Araneidae |
| Genus: | Cyrtophora |
| Species: | C. citricola
|
| Binomial name | |
| Cyrtophora citricola (Forskål, 1775)
| |
| Synonyms | |
|
Aranea citricola | |
Cyrtophora citricola, also known as the tropical tent-web spider, is an orb-weaver spider in the family Araneidae. They can be found in Asia, Africa, Australia, Costa Rica, Hispaniola, Colombia, and the warmer parts of Europe. In 2000, it was also discovered in Florida.
Although it is in the family commonly called orb web spiders, their webs are considered atypical compared to orb webs. Their webs have been described as having a mesh-like, horizontal appearance. The difference in their web silk can be explained by unique physiological changes to their spinning apparatuses. The spiders have developed unique prey- capturing techniques which utilize their atypical webs. These spiders can be social, and their webs are often built in large matrices next to one another.
These spiders are most active at night, preferring to carry out only necessary tasks during the day. They primarily remain idle and try to stay out of sight from predators during the day. At night, they conduct most of their foraging and prey capture.[1] They may also have to ward off other spiders in the colony that may try and claim their webs.[2]
C. citricola's color can vary greatly. Many sport a black and white pattern while others are brown. Males sometimes appear black. Body length in females normally reaches 10 mm, while males are only 3 mm long.
Taxonomy
The common name for this spider “tropical tent-web” derives from Forsskal’s first observations. The spider was first identified in citrus trees and in horizontal webs that were described as nets. [3]
Peter Forsskal discovered the species in the Arabian Peninsula posthumously naming it Aranea Citricola in 1775.[3] It was classified in the Araneidae family because it creates orb-webs.[2] Between 1776 and 1864 the spider was classified under the genus Epeira, another synonym for Aranea, more commonly know as Araneus. The spider was later moved from the genus Aranea to Cyrtophora by Eugene Simon in 1864. This decision was made because their orb webs differ from those constructed by the genus Aranea.[4] C. citricola webs are horizontal and tent-shaped aligning with other species in the genus Cyrtophora. Like others in the Cyrtophora family, their 2nd, 3rd, and 4th legs have a shorter combined patella and tibia length than femurs within the same legs. Additionally, they share the same bent-back eye pattern: a typical family defining trait. They differ from the Manogea genus of orb-web spiders due to their broader cephalic structures.
Cyrtophora citricola abessinensis was one subspecies under C. citricola that was later discovered to be a holotype in 1944.[5]
Description
Cyrtophora citricola spiders are a medium brown color, though may display darker brown spots on the abdomen. In Florida, for example, male spiders are black and females vary in their coloring and can camouflage in their webs. In Turkey, they usually appear brown with grey hair. C. citricola male and female spiders exhibit sexual dimorphism. The male spiders are generally 3mm in length. They are significantly smaller than the female spiders that are usually 10mm in length. Uniquely, C. citricola exhibit a horizontal bifurcation at the posterior abdomen.[6][7] It is also distinguishable from its other relatives by its two pairs of dorsal tubercles and its posterior tubercles pair.[8] The females have been found to exhibit white hairs. C. citricola typically has seven denticles. The opisthosoma has two dorsal pairs of protuberances and two posterior lobes.[9]
They are most active from the middle of summer to the beginning of fall. Adults are observed to mate between June and September.[8]
Webs
Web type
Cyrtophora citricola build tent-webs that possess a horizontal orb web and a network of webs above the horizontal orb web resembling a tent.[2] These webs can either by solitary or have aspects of sociality within colonies. The spiders exhibit advantages living in colonies, but there is no strong selection towards either solitary or colonial living.[10] Within colonies, the horizontal orb webs are maintained by individuals. These webs are solitary.[1] Above the orb, they create a thick silk strand barrier, and below the orb, they create a thinner barrier. The barrier above the web is used to deflect insects onto the orb web below.[2] These webs above and below the horizontal orb wens are communal and maintained by the colony.[1] The web itself and silk are not sticky.[2][7] Instead, the webs appear as a fine mesh curtaining, made of radii and a nonadhesive structural spiral. This is unique from the typical Araneidae family webs, as they do not contain a viscid spiral. These webs are especially durable, and perhaps have adapted to be created in more open spaces such as trees. The webs are strong enough to withstand environmental pressures (i.e. rain and wind).[11] Unlike adhesive webs, which must be respun daily, these non-adhesive webs are only repaired when damaged. Most of this damage occurs at the peripheries of colony webs where the costs to create orb-webs are high. The center of these colonies do not require frequent repairs, saving the spider the constant investment of respinning the web.[2] The webs may be large enough to span entire trees and have been found on a large variety of tree species.[7][6] C. citricola prefer to build their webs on firm substrates rather than non-firm substrates. Spiders who build webs on firmer substrates tend to make webs which last for long periods of time.[12]
The spiders typically will rest with all of their legs underneath their body when they are not watching over egg sacs. They sit on the hub of the web, on the horizontal portion. This positioning occurs both at night and at some times during the day.[11]
Web Behaviors
Jerking, an act of quickly pulling the radii with leg I, has been observed in this species. Web jerking may occur in response to movement in the web and prey capturing. It may allow the spider to accurately find objects in its web, thus assisting in actions such as prey location and signal transmission.[11]
These spiders will also engage in motions that cause sudden, rapid shaking of their webs. This shaking is created by a downward motion of the spiders' legs. C. citricola may engage in web shaking to dislodge prey stuck in the upper barrier of the net so that the spider can access it. It may also shake off any approaching kleptoparasites.[11]
Diet
C. citricola capture their prey in the upper, thicker barrier part of the web. The rate of prey per capita due to web deflection is relatively low, which may cause spiders to aggregate together.[2] Spiders who live in social aggregates have webs that are more efficient at capturing prey than those who do not live in groups.[2][7]
The process of prey capturing includes multiple steps. The first step is either biting the prey or wrapping it in silk. The second step is pulling and cutting out of the top part of the web. The third step is transporting the prey to the hub of the web by either carrying it in their jaws or carrying it on silk. The fourth step is feeding on the prey in the hub of the web.[11]
There are four basic attack sequences that have been observed in C. citricola. In the first variation, the spider wraps its prey and then bites it. After biting it removes the prey from the web, the spider rewraps it, and transports it to the hub. The second sequence follows the steps of the first variation but skips the biting stage. The third variation starts with the spider biting its prey and then wrapping the prey. The prey is later cut-out of the web and then rewrapped before being transported to the web hub. The fourth sequence involves spiders biting the prey and then pulling or cutting the prey. The prey is transported to the hub in the spider’s jaws. Whether the prey is bitten, wrapped, or both is determined by the type of prey that is captured.[11]
Some common prey of C. citricola include moths and flies, which are usually immobilized by biting and carried to the hub on silk. Orthopteras are another type of prey where C. citricola use a wide variety of sequences in their captures. Other common prey include dragonflies, beetles, and pentatomids.[11]
Habitat and distribution
Cyrtophora citricola can be found in Asia, Africa, Australia, Costa Rica, Hispaniola, Colombia, and the warmer parts of Europe.[1] They are unable to survive in temperature below -1°C.[as c 1][7] It was also discovered in Florida in 2000. In Florida, it makes its webs on canal bridges from the east end of Everglades National Park to the east coast. These spiders live in a wide range of environments, but they are most prevalent in olive orchards and undergrowth.[8] They are found in tropical agricultural operations.[1]
These spiders are unique compared to their close relatives due to their widespread habitation.[13] Most of their close relatives are concentrated in specific parts of the world. However, their introduction to the Americas has caused many problems. They are now becoming increasingly common in agricultural and urban spaces. As a result, they are damaging farm operations. Currently, there are active efforts to remove these spiders as their webs are known to damage flora.[6]
Home range and territoriality
Cyrtophora citricola exhibits territorial behavior over their orb-webs. However, tent-webs are seen as communal, and no aggressive behavior has been documented between spiders that travel across these webs. At night there are conflicts between orbless spiders and those that possess orbs. These fights occur due to competition for better feeding locations. In fights, larger spiders are typically dominant over smaller spiders.[10] Invading spiders may come from the colony's periphery, where costs to build webs may be high due to more frequent repair and diminished prey capture. Peripheral webs often experience damage from weather or predators that central webs do not.[2] The conflict ensues typically when an orbless intruder approaches the web and vibrates it. This action is a sign of an attack which solicits the same response from the defending spider. The vibrations between the attacker and the defender continue for up to a few minutes. However, the invader rarely captures the web under dispute and eventually retreats.[2]
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Mating
Upon reaching adulthood, the male spiders will look for females. Males die shortly after mating has occurred.[15] These spiders exhibit sexual cannibalism at high rates. The female spiders often will eat the male spiders directly after mating with them.[16] This sexual cannibalism encourages males to be very choosy in who they pick as their female mate. Males preferred to mate with younger, more well- fed females.[17] Additionally, males prefer mating with virgin females over females that have already copulated. Females are not choosy in their male mates. [17]
The female initiates the mating process. Females traditionally approach the male until they are about 1cm from the male. At this point, the male advances quickly towards the female and tries to insert his pedipalp. If successful, copulation begins and lasts for a few seconds.[17]
The male Cyrtophora citricola does not somersault into the female’s chelicerae. The female bends her cephalothorax and orients herself to attack the male’s abdomen while the pedipalp is in the female. The male is then eaten and the pedipalp detaches from the female.[17]
Parental care
Egg laying
The egg sacs of Cyrtophora citricola have a diameter ranging from 12-20mm. These egg sacs are laid in chains of up to 10 sacs in a row on the webs. The eggs are colored bluish- green. Each egg sac contains between 100 and 200 eggs. The eggs are shaped as flat ellipticals.[7] The number of eggs produced depends on various environmental factors, including food availability. Solitary females can produce approximately up to 20% more eggs than females living in colonies.[1] The reduction of eggs in colonies may be due to better cocoon protection from parasites and reduced predation.[18]
Egg guarding
Females with egg sacs typically will rest directly underneath the egg sac in order to guard them.[11]
Social behavior
Cyrtophora citricola may exhibit aggregate social interactions with one another and live cooperatively in groups. The spiders make their own individual webs, but these individuals webs are interconnected. The large network of webs with neighboring spiders creates a massive web matrix. They generally coexist peacefully. However, if another nearby spider tries to take their prey, they may exhibit aggressive behaviors.[7] Colony living may have evolved because of the foraging benefits of group living for the spiders. However, sometimes when the spiders are under food- stress, they do not prefer to live in groups. This suggests there may be some other evolutionary reason that group living evolved in this species.[10]
Some C. citricola live solitarily. When compared to those living in colonies, the solitary spiders have larger webs, produce more eggs, and have more kleptoparasites.[1]
Enemies
Argyrodes argyrodes, another species of spider, has been found to steal both the Cyrtophora citricola's prey and eggs.[7] In addition, Holocnemus pluchei have been found to build their webs off of C. citricola's webs. In addition, Holocnemus pluchei have exhibited aggressive behavior towards C. citricola. They have been observed attacking and eating C. citricola juveniles.[1] C. citricola will drop to the ground if attacked, in an attempt to camouflage.[15]
Argyrodes gibbosus often acts as a kleptoparasite on C. citricola, stealing prey that the C. citricola caught.[1] They are known to switch strategies depending on where the host is located. The prey is stolen when the host is in the web. They have been observed waiting for the C. citricola to go foraging before consuming their eggs.[19]
Pediobius pyrgo are a type of wasp that lays their eggs in C. citricola egg sacs. They are present in the Iberian Peninsula and in the Canary Islands.[20] Philolema palanichamyi are another type of wasp that lays their eggs in C. citricola egg sacs. They affect these spiders primarily in the Canary Islands and can parasitize around 40% of egg sacs. Wasp larvae feed on the spider’s eggs and each larva will devour significant portions of the egg sacs. The incubation takes approximately seven weeks. These often cause a large portion of parasitized spider egg-sacs to die. Parasitization approximately decreases emerging spiderling populations by 60%.[20]
If C. citricola is disturbed by a predator, it may pull all of its legs inwards towards its abdomen.[11]
Protective coloration and behavior
They can change their abdomen's color to blend in with the environment.[2] The coloring of the female Floridian spiders allows them to appear as brown, dead leaves when sitting in their webs, preventing potential predators from spotting them.[7]
Physiology
Thermoregulation
Cyrtophora citricola has been shown to exhibit thermoregulative behaviors. This trait is common in web-building spiders, including Nephila clavipes, N. maculata, and Frontinella communis . During the hottest portions of the day, the spiders will position themselves so that as little surface area of their body is shown to the sun as possible.[11]
Spinning apparatus
Other Araneidae species have a triad complex on their posterior spinnerets which produce a gluey thread material for the webs from the piriform glands. C. citricola do not have this and are thus unable to make gluey thread web material. The consequence of this is that C. citricola create a unique non-sticky, mesh-like web.[21]
Interactions
Agricultural impact
Plants that have high concentrations of Cyrtophora citricola may experience partial death where webs span over leaves. This may be due to the thickness of the webs that can inhibit airflow to the leaves. As a result, some authorities have opted to use high-pressure water sprayers and chemical controls to exterminate colonies.[6]
C. citricola has been problematic for many agricultural operations in South American including coffee and citrus plantations. Additionally, they have been increasingly common in the Southern states of North America. In Florida, they have become a common backyard nuisance.[20]
References
- ^ a b c d e f g h i Leborgne, R.; Cantarella, T.; Pasquet, A. (1998-05-01). "Colonial life versus solitary life in Cyrtophora citricola (Araneae, Araneidae)". Insectes Sociaux. 45 (2): 125–134. doi:10.1007/s000400050074. ISSN 1420-9098. S2CID 12052536.
- ^ a b c d e f g h i j k Rypstra, Ann L. (1979). [http://link.springer.com/10.1007/BF00293677 "Foraging flocks of spiders: A study of aggregate behavior in Cyrtophora citricola Forsk�l (Araneae; Araneidae) in West Africa"]. Behavioral Ecology and Sociobiology. 5 (3): 291–300. doi:10.1007/BF00293677. ISSN 0340-5443. S2CID 37651094.
{{cite journal}}: replacement character in|title=at position 88 (help) - ^ a b Forsskal, Peter (1775). Descriptiones Animalium – Avium, amphiborum, insectorum, vermium quæ in itinere orientali observavit Petrus Forskål.
- ^ Simon, Eugène (1892). Histoire naturelle des araignées. /. Paris: Roret. doi:10.5962/bhl.title.51973.
- ^ Natural History Museum Bern. "NMBE - World Spider Catalog". wsc.nmbe.ch. Retrieved 2020-12-15.
- ^ a b c d Levi, Herbert Walter (1997). "The American Orb Weavers of the Genera Mecynogea, Manogea, Kapogea and Cyrtophora (Araneae: Araneidae)". Bulletin of the Museum of Comparative Zoology at Harvard College. 155: 215–255 – via biodiversitylibrary.
- ^ a b c d e f g h i "Colonial Tentweb Orbweaver Cyrtophora citricola". entnemdept.ufl.edu. Retrieved 2020-10-20.
- ^ a b c Elverici, Mert; Teksam, Ilyas; Özkütük, Recep Sulhi; Kunt, Kadir Bogaç (2012-12-20). "Cyrtophora citricola (Araneae: Araneidae: Cyrtophorinae), a first record for Turkey". Arachnologische Mitteilungen. 44: 7–9. doi:10.5431/aramit4402.
- ^ "araneae - Cyrtophora citricola". araneae.nmbe.ch. Retrieved 2020-10-20.
- ^ a b c Yip, Eric C.; Levy, Tanya; Lubin, Yael (2017-07-28). "Bad neighbors: hunger and dominance drive spacing and position in an orb-weaving spider colony". Behavioral Ecology and Sociobiology. 71 (8): 128. doi:10.1007/s00265-017-2357-6. ISSN 1432-0762. S2CID 23620793.
- ^ a b c d e f g h i j "The Predatory Behavior of CYRTOPHORA" (PDF). Arachnol.
- ^ Brenes, Ruth Madrigal (August 2012). "Substrate selection for web-building in Cyrtophora citricola (Araneae: Araneidae)". The Journal of Arachnology. 40 (2): 249–251. doi:10.1636/Hi11-30.1. ISSN 0161-8202. S2CID 86047610.
- ^ Sewlal, Jo-Anne Nina; Starr, Christopher K. (2011-05-23). "Preliminary Survey of the Spider Fauna of Great Inagua, Bahamas, W.I." The International Journal of Bahamian Studies. 17 (2): 3. doi:10.15362/ijbs.v17i2.137. ISSN 2220-5772.
- ^ "Tropical Tentweb Spider - Cyrtophora citricola, Gorongosa National Park, Mozambique" by Judy Gallagher is licensed under CC BY 2.0 license. Copyright
- ^ a b "Cyrtophora citricola (Tent-web spider)". biodiversityexplorer.info. Retrieved 2020-10-20.
- ^ www.biointeractive.org https://www.biointeractive.org/classroom-resources/mate-choice-spiders. Retrieved 2020-10-20.
{{cite web}}: Missing or empty|title=(help) - ^ a b c d Yip, Eric C.; Berner-Aharon, Na’ama; Smith, Deborah R.; Lubin, Yael (2016-06-01). "Coy Males and Seductive Females in the Sexually Cannibalistic Colonial Spider, Cyrtophora citricola". PLOS ONE. 11 (6): e0155433. Bibcode:2016PLoSO..1155433Y. doi:10.1371/journal.pone.0155433. ISSN 1932-6203. PMC 4889064. PMID 27249787.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Smith, Deborah R. R. (1983). "Ecological costs and benefits of communal behavior in a presocial spider". Behavioral Ecology and Sociobiology. 13 (2): 107–114. doi:10.1007/BF00293800. ISSN 0340-5443. S2CID 25060518.
- ^ Pasquet, Alain; Leborgne, Raymond; Cantarella, Theresa (2010-04-26). "Opportunistic Egg Feeding in the Kleptoparasitic Spider Argyrodes gibbosus". Ethology. 103 (2): 160–170. doi:10.1111/j.1439-0310.1997.tb00015.x.
- ^ a b c Chuang, Angela; Gates, Michael W.; Grinsted, Lena; Askew, Richard; Leppanen, Christy (2019-09-02). "Two hymenopteran egg sac associates of the tent-web orbweaving spider, Cyrtophora citricola (Forskål, 1775) (Araneae, Araneidae)". ZooKeys (874): 1–18. doi:10.3897/zookeys.874.36656. ISSN 1313-2970. PMC 6733805. PMID 31537957.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Peters, Hans M. (1993-10-01). "Functional organization of the spinning apparatus of Cyrtophora citricola with regard to the evolution of the web (Araneae, Araneidae)". Zoomorphology. 113 (3): 153–163. doi:10.1007/BF00394856. ISSN 1432-234X. S2CID 44616019.
- Sources
- Álvares, É.S.S. & De Maria, M. (2004). First record of Cyrtophora citricola (Forskål) in Brazil (Araneae, Araneidae). Revista Brasileira de Zoologia 21(1):155-156 PDF doi:10.1590/S0101-81752004000100026
- Edwards, G.B. (2006): Cyrtophora citricola (Araneae: Araneidae), a Colonial Tentweb Orbweaver Established in Florida. Entomology Circular 411:. PDF
- Platnick, Norman I. (2009): The world spider catalog, version 10.0. American Museum of Natural History.
External links
- Pictures of C. citricola
- Pictures and information on C. citricola from Portugal
- Cyrtophora citricola[permanent dead link] on the UF / IFAS Featured Creatures website.
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