Arachnocampa

Arachnocampa
Threads of the larvae of Arachnocampa luminosa
Systematics
Class : Insects (Insecta) Order : Fly (Diptera) Subordination : Mosquitoes (Nematocera) Superfamily : Sciaroidea Family : Longhorn mosquitoes (Keroplatidae) Genre : Arachnocampa
Scientific name
Arachnocampa
Edwards , 1924

Arachnocampa is a genus of longhorn mosquitoes (Keroplatidae)comprising four speciesthatshow bioluminescence as a larval stage. They live mainly in New Zealand and Australia in caves and grottoes or sheltered places in the forest.

The first discovered species, Arachnocampa luminosa , was originally described under the generic name Bolitophila ("mushroom-loving"). Frederick W. Edwards separated the species from Bolitophila Meigen in 1924 and established the new genus Arachnocampa ("spider caterpillar" because the larvae spin silk threads to catch prey) for Arachnocampa luminosa .

description

The species of arachnocampa go through a life cycle from a 3–5 mm long egg to larvae, which pupate and then become an adult mosquito. At 6 to 12 months, the larval stage takes up the greater part of the life span depending on the food supply.

The larva spins a silk nest on the ceiling of the cave and then hangs up to 70 silk threads around the nest. These are up to 30 or 40 cm long and covered with mucus droplets. The larvae can only live in places with no wind, otherwise their lines get caught. Hence, they prefer caves, overhangs and deep rainforest. In some species, the droplets also contain poison in order to be able to overwhelm the captured prey more quickly.

The larvae glow to lure prey into their catch threads. It is possible that the larvae-covered cave ceiling of the prey simulates a clear, starry sky at night. Hungry larvae shine brighter than those that have just eaten. Prey includes midges , mayflies , caddis flies , mosquitoes , moths and even small snails and millipedes. If the prey sticks to a catch thread, it pulls the larva upwards at up to 2 mm / s and eats it. When there is a lack of food, the larvae go on to cannibalism and eat other larvae, pupae and adult mosquitoes.

The glow is a result of the reaction of luciferin in the presence of the enzyme luciferase , adenosine triphosphate as an energy carrier and oxygen. The luminous organs are modifications of the Malpighian vessels in the abdomen .

The body of the larvae is soft, but the head capsule is hard. When the head cannot find enough space, the larva sheds its skin. This happens four times. At the end of the larval stage, the larva reaches a length of up to 3 cm and pupates into a pupa that is hanging from the ceiling and glows periodically. The pupal stage lasts 1–2 weeks. The male stops glowing shortly before hatching, while the female pupae glow more. It is believed that the females' glow should attract the males so that they can wait for the females as soon as they hatch.

The mosquitoes of both sexes do not ingest food and are short-lived as they are only needed for mating and egg-laying. They are bad fliers, often staying close to the pupal site and forming colonies there. The female lays around 130 eggs in piles of 40 to 50 and dies soon after. The larvae hatch after about 20 days.

The larvae are sensitive to light and disturbances. When they touch their catch threads they withdraw into the nest and stop glowing. They have few enemies and the greatest threat comes from interference from humans.

species

• Arachnocampa luminosa lives on both islands of New Zealand. Her Māori name is Titiwai . The Waitomo Caves in the North Island are a well-known habitat and tourist attraction. This species was discovered for science in 1871 when it wascollectedin a gold mine in the Thames area . At first it was thought to be related to the European fireflies, but in 1886 a teacher from Christchurch showedthat they are the larvae of a mosquito, not a beetle. The species wasnamed Bolitophila luminosa in 1891and placed in the genus Arachnocampa in1924. The eggs, larvae and pupae, even adult mosquitoes, areeatenby harvestmen . The small orange-colored harvestmen live in the same caves, larger spiders visit the caves for food and protection. A fungus also attacks the species and gradually kills the larvae. The fungal spores are distributed by air movement. However, since the larvae live in places protected from the wind, the spores cannot spread widely.
• Arachnocampa richardsae lives in New South Wales . The Newnes Glow Worm Tunnel in the Blue Mountains is a well-known habitat.
• Arachnocampa tasmaniensis lives in Tasmania . One location is the Marakoopa Cave in Mole Creek near Cradle Mountain .
• Arachnocampa flava lives in Queensland . The natural bridge in Springbrook National Park in the Gold Coast hinterlandis a well-known habitat.
• Arachnocampa sp. "Mount Buffalo" is a possible fifth species. A colony of arachnocampa was found in an alpine cave on Mount Buffalo in Victoria . Research suggests that it is a new species related to A. tasmaniensis and A. luminosa . Their presence suggests that the rainforest once extended up to the cave. The government of Victoria has classified the so-called Mt. Buffalo Glow-Worms as an endangered species.

literature

• Roy Alexander Harrison: Glow-Worm . In: Alexander Hare McLintock (Ed.): An Encyclopaedia of New Zealand . Wellington 1966 ( online [accessed December 17, 2015]).
• Victor B. Meyer-Rochow: The New Zealand Glowworm . Waitomo Caves Museum Society, Waitomo Caves 1990, ISBN 0-908683-09-X .
• Ormiston Walker and Judy Kerdel: The Glow-Worm. MacMillan New Zealand, 1990, ISBN 0-7329-0121-9 . (Children's book)
• Article Glowworm Encyclopædia Britannica , 15th ed.
• HC Baker: Distribution and phylogenetic relationships of Australian glow-worms Arachnocampa (Diptera, Keroplatidae). In: Molecular Phylogenetics and Evolution 48, 2008, pp. 506-514.
• HC Baker, DJ Merritt (2003): Life cycle of an Australian glow-worm Arachnocampa flava Harrison (Diptera: Keroplatidae: Arachnocampa). In: Australian Entomologist 30 (2), 2008, pp. 45-55.
• HC Baker Australian glow-worms: Managing an important biological resource. In: Australasian Cave and Karst Management Association Inc. 53: 2003, pp. 13-16.
• HC Baker Dipteran glow-worms: Marvelous maggots weave magic for tourists. (Eds. JH Skevington and PT Dang) Exploring the diversity of flies (Diptera) in. Biodiversity 3 (4), 2002, pp. 3–28.
• HC Baker A biological basis for management of glow-worm populations of ecotourism significance. In: Wildlife Tourism Research report series: No 21, CRC for Sustainable Tourism, Gold Coast, QLD. 2002, p. 76 ff.
• RA Broadley, IAN Stringer: Prey attraction by larvae of the New Zealand glowworm, Arachnocampa luminosa (Diptera: Mycetophilidae) . Invertebrate Biology 120 (2), pp. 170-177.

Individual evidence

1. ^ Frederick Wallace Edwards: A Note on the "New Zealand Glow-worm" (Diptera, Mycetiphilidae). In: Annals and Magazine of Natural History. ser. 9, 14, London 1924, pp. 175-179.
2. ^ Ross Piper : Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals , Greenwood Press , 2007.
3. ↑ LBS Green: The fine structure of the light organ of the New Zealand glow-worm Arachnocampa luminosa (Diptera: Mycetophilidae). In: Tissue and Cell. 11/1979, pp. 457-465.
4. ↑ The Lure of Glow Worms. Science feature from the Australian Broadcasting Commission
5. ↑ Flora and Fauna Guarantee Act 1988 Threatened List. (PDF; 69 kB) Department of Sustainability and Environment Flora, April 2006, archived from the original on September 29, 2007 ; Retrieved on August 11, 2012 (English, original website no longer available, link to WaybackMachine from September 29, 2007).