Metellina

Most similar to the related genus Meta. Distinguished by flat epigynal plate with posterior-facing copulatory openings, canoe-shaped tapetum in secondary eyes, and single macroseta on palpal patella.

Abdomen longer than wide, usually without tubercles. Secondary eyes possess a canoe-shaped tapetum. Posterior lateral eyes located on a single tubercle. Epigynal plate flat with posterior-facing copulatory openings. Fertilization ducts originate near anterior area of spermathecae with mass of accessory glands near copulatory ducts. Palpal patella bears one macroseta.

Web dwellers that construct webs low in vegetation. Includes both epigean (woodland) and hypogean (cave) species; M. merianae occurs in caves while M. mengei inhabits woodland. Web inclination affects prey capture success.

Primarily Eurasia. Two species found in North America; M. segmentata introduced to Canada. African species include M. barreti, M. gertschi, M. longipalpis, M. merianopsis, M. minima, M. villiersi, and M. haddadi from South Africa.

Active during autumn; commonly known as Autumn Spider.

• Megaetaira madida - parasitoidAlters web architecture of M. merianae

Males of M. segmentata compete for access to mates by guarding orb webs of mature females. Male contests determined by relative body size and prior residency; larger males (>10% size advantage) nearly always win, while prior residents win when size asymmetries are smaller. Contest duration decreases exponentially with increasing size asymmetry. Males adjust fighting effort based on female fecundity. Males perform leg-twitching vibrations on female webs that mimic struggling prey, causing females to adopt predatory posture rather than cannibalistic posture during courtship, thereby reducing sexual cannibalism risk.

Orb-web predators; M. mengei shows no significant edge effect on prey capture quantity in woodland habitats, suggesting minimal impact from habitat fragmentation.

M. segmentata is the most abundant orb-weaving spider in Germany and has been introduced to Canada.

• MetaMost similar genus; Metellina name derived from alteration of Meta
• TetragnathaHistorical misplacement of some African species originally described as Meta but belonging to Tetragnathinae rather than Metainae
• LeucaugeM. meruensis likely belongs to Leucauge or related genus rather than Metellina

• orb-weaver
• web-building
• sexual selection
• male-male competition
• sexual cannibalism avoidance
• cave-dwelling
• introduced species
• autumn activity

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Male exploitation of female predatory behaviour reduces sexual cannibalism in male autumn spiders, Metellina segmentata
• A comparison of morphology and web geometry between hypogean and epigean species of Metellina orb spiders (family Tetragnathidae)
• A comparison of morphology and web geometry between hypogean and epigean species of Metellina orb spiders (family Tetragnathidae)
• No edge effect on quantity of prey captured in the forest-dwelling tetragnathid orb spider Metellina mengei
• A Synopsis of African Metellina (Aranei, Tetragnathidae, Metainae) with Description of a New Species from South Africa
• Figure 1 from: Hesselberg T, Simonsen D (2019) A comparison of morphology and web geometry between hypogean and epigean species of Metellina orb spiders (family Tetragnathidae). Subterranean Biology 31: 53-65. https://doi.org/10.3897/subtbiol.31.36222
• Figure 1 from: Hesselberg T, Simonsen D (2019) A comparison of morphology and web geometry between hypogean and epigean species of Metellina orb spiders (family Tetragnathidae). Subterranean Biology 32: 1-13. https://doi.org/10.3897/subtbiol.32.36222
• Web architecture alteration of the orb web weaving spiderMetellina merianae(Araneae, Tetragnathidae) induced by the parasitoidMegaetaira madida(Ichneumonidae,Polysphinctagroup)
• Spiders of the generaAraniella, Zygiella, ZillaandMangora(Araneae, Araneidae) from Israel, with notes onMetellinaspecies from Lebanon
• Fighting in Males of the Autumn Spider, Metellina segmentata: Effects of Relative Body Size, Prior Residency and Female Value on Contest Outcome and Duration
• Figure 2 from: Hesselberg T, Simonsen D (2019) A comparison of morphology and web geometry between hypogean and epigean species of Metellina orb spiders (family Tetragnathidae). Subterranean Biology 32: 1-13. https://doi.org/10.3897/subtbiol.32.36222
• Figure 2 from: Hesselberg T, Simonsen D (2019) A comparison of morphology and web geometry between hypogean and epigean species of Metellina orb spiders (family Tetragnathidae). Subterranean Biology 31: 53-65. https://doi.org/10.3897/subtbiol.31.36222