Английская Википедия:Glomeris marginata
Шаблон:Short description Шаблон:Italic titleШаблон:Speciesbox
Glomeris marginata is a common European species of pill millipede. It is a short millipede, rounded in cross-section, which is capable of rolling itself up into a ball ("volvation") when disturbed. This behaviour is also found in the pill woodlouse Armadillidium, with which G. marginata is often confused.[1]
Distribution
Glomeris marginata is found throughout central and north-western Europe, from Poland and Scandinavia to Spain and Italy.[2] In the British Isles, it is found in all areas south of the Central Belt of Scotland.[3]
Description
Glomeris marginata grows up to Шаблон:Convert long and Шаблон:Convert wide, and is covered by twelve black dorsal plates with white rims.[4][5] Each segment except those at the front and back bears two pairs of legs, with around 18 pairs in total.[4] This distinguishes pill millipedes from pill woodlice, both of which are called "pillbugs" — woodlice have 7 pairs of walking legs, one per body segment, while millipedes have more pairs, and with two pairs to each apparent body segment.
When rolled into a ball, G. marginata can be distinguished from a rolled–up pill woodlouse by the asymmetrical ball it rolls into; pill woodlice roll into much more perfect spheres.[6] The cuticle is also darker and shinier, and the antennae are shorter.[7] The head and tail of a woodlouse have a greater number of small plates, while the head of Glomeris is protected by a single large shield, and it lacks the uropods of woodlice at the read end.[4] Although usually black, red, yellow and brown individuals do occasionally occur.[1]
Ecology
Glomeris marginata lives in leaf litter as well as in grass and under stones, with a preference for calcareous soils.[1] In domestic gardens, they are most frequent along hedgerows and at the bases of old walls, where the mortar has started to crumble, leaching lime into the soil.[4][7] It is less prone to desiccation than other millipedes and can be found in the open, even in sunny weather,[5] although they are more active at night and prefer more humid areas.[1] G. marginata feeds on old, rotting leaves, despite the higher nutrient content of freshly–fallen leaves, and G. marginata can be responsible for recycling a significant proportion of the nutrients in the leaf litter.[8]
Predators of Glomeris marginata are reported to include the starling, the common toad, the woodlouse spider,[7] and hedgehogs.[5] As well as rolling up into a ball for protection, G. marginata produces noxious chemicals to ward off potential predators, as many millipedes do. One to eight drops of a viscid fluid are secreted, containing the quinazolinone alkaloids glomerin and homoglomerin, dissolved in a watery protein matrix.[9] These chemicals act as antifeedants and toxins to spiders, insects and vertebrates, and the fluid is sticky enough to entrap the legs of ants.[9] Having completely discharged these chemical defences, it can take up to four months for the millipede to replenish their supplies.[9]
Reproduction and life cycle
Breeding takes place cyclically in spring and summer. Male G. marginata are capable of producing a pheromone which attracts females, although this is only believed to be effective over short distances.[10] They then transfer sperm to the female using their gonopods, specially modified legs. After fertilisation, the females lay 70–80 eggs, each about 1 mm long, and each wrapped singly in a capsule of digested earth.[1] The eggs hatch after a period of about two months, with the duration depending on factors including temperature.[5] Development lasts for up to three years, and involves nine moults, following which moults occur periodically as adults.[1] Females are fertile for several years, and can produce six broods over their lifetime,[5] which can be up to eleven years.[1]
References
External links
- ↑ 1,0 1,1 1,2 1,3 1,4 1,5 1,6 Шаблон:Cite web
- ↑ Шаблон:Cite webШаблон:Dead link
- ↑ Шаблон:Cite web
- ↑ 4,0 4,1 4,2 4,3 Шаблон:Cite web
- ↑ 5,0 5,1 5,2 5,3 5,4 Шаблон:Cite webШаблон:Better source
- ↑ Шаблон:Cite web
- ↑ 7,0 7,1 7,2 Шаблон:Cite web
- ↑ Шаблон:Cite journal
- ↑ 9,0 9,1 9,2 Шаблон:Cite journal
- ↑ Шаблон:Cite journal
