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Diplura

(Redirected from Dipluran)
For other uses, see Diplura (disambiguation).

The order Diplura ("two-pronged bristletails") is one of three orders of non-insect hexapods within the class Entognatha (alongside Collembola (springtails) and Protura).[3] The name "diplura", or "two tails", refers to the characteristic pair of caudal appendages or filaments at the terminal end of the body.

Diplurans
Temporal range: Late Carboniferous–Recent[1]
Campodea staphylinus, Belgium
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Clade: Pancrustacea
Subphylum: Hexapoda
Order: Diplura
Börner, 1904
Families [2]

Around 800 species of diplurans have been described.

Anatomy

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A dipluran of the family Campodeidae

Diplurans are typically 2–50 millimetres (0.08–1.97 in) long, with most falling between 7 and 10 millimetres (0.28 and 0.39 in).[4] However, some species of Japyx may reach 50 mm (2.0 in).[5] They have no eyes and, apart from the darkened cerci in some species, they are unpigmented.[5] Diplurans have long antennae with 10 or more bead-like segments projecting forward from the head.[6] The abdomens of diplurans bear eversible vesicles, which seem to absorb moisture from the environment and help with the animal's water balance.[6] The body segments themselves may display several types of setae, or scales and setae.[7]

Diplurans possess a characteristic pair of cerci projecting backwards from the last of the 11 abdominal somites.[8] These cerci may be long and filamentous or short and pincer-like,[9] leading to occasional confusion with earwigs.[10] Some diplurans have the ability to shed their cerci if necessary (autotomy). Moulting occurs up to 30 times throughout the life of a dipluran, which is estimated to last up to one year.

As entognaths, the mouthparts are concealed within a small pouch by the lateral margins of the head capsule. The mandibles usually have several apical teeth.[7] Diplurans do not possess any eyes or wings.[4]

In males, glandular setae or disculi may be visible along the first abdominal sternite. External genital organs are present on the eighth abdominal segment.[7]

Ecology

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Diplurans are common in moist soil, leaf litter or humus,[11] but are rarely seen because of their size and subterranean lifestyles.[6] They have biting mouthparts and feed on a variety of live prey and dead organic matter.[3] Those species with long cerci are herbivorous.[10]

Diplurans are found on nearly all land masses, except Antarctica and several oceanic islands.[7] Their role as soil-dwelling organisms may play a key role in indicating soil quality, and as a measure of anthropogenic impact (e.g. soil nutrient depletion as a result of farming).[12][13]

Reproduction

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Like other non-insect hexapods, diplurans practice external fertilisation. Males lay up to 200 spermatophores a week, which are held off the ground by short stalks and probably only remain viable for about two days.[11] The female collects the spermatophore with her genital opening, and later lays eggs in a cavity in the ground.[10][6][11] The hatchlings (or nymphs) do not undergo metamorphosis, but resemble the adults, apart from their smaller size, lesser number of setae and their lack of reproductive organs.[3]

Lineages

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Anatomy of Campodea (Campodeidae) and Japyx (Japygidae)

Several major lineages within Diplura are readily recognizable by the structure of their cerci.

Relatives

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The relationships among the four groups of hexapods are not resolved, but most recent studies argue against a monophyletic Entognatha.[15] The fossil record of the Diplura is sparse, but one apparent dipluran dates from the Carboniferous.[2] This early dipluran, Testajapyx, had compound eyes, and mouthparts that more closely resembled those of true insects.

References

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  1. ^ Hoell HV, Doyen JT, Purcell AH (1998). Introduction to Insect Biology and Diversity (2nd ed.). Oxford University Press. p. 320. ISBN 978-0-19-510033-4.
  2. ^ a b Maddison DR (January 1, 2005). "Diplura". Tree of Life Project. Archived from the original on October 17, 2012. Retrieved December 13, 2006.
  3. ^ a b c d e "Guide to New Zealand Soil Invertebrates". Massey University. 2006.
  4. ^ a b Bugguide.net. Class Diplura - Two-pronged Bristletails
  5. ^ a b Kendall D (2005). "Diplura". Kendall Bioresearch Services.
  6. ^ a b c d "Diplura". McMaster University. 1999. Archived from the original on 2007-03-27.
  7. ^ a b c d Allen RT (Dec 2002). "A Synopsis of the Diplura of North America: Keys to Higher Taxa, Systematics, Distributions and Descriptions of New Taxa (Arthropoda: Insecta)". Transactions of the American Entomological Society. 128 (4): 403–466. JSTOR 25078790.
  8. ^ "Diplura". The Earthlife Web. November 11, 2005. Archived from the original on 2006-12-05.
  9. ^ "Diplura". Iziko Museums of Cape Town. 2004. Archived from the original on 2007-09-26.
  10. ^ a b c "Diplura". CSIRO Entomology.
  11. ^ a b c Meyer JR (2005). "Diplura". North Carolina State University. Archived from the original on 2012-02-05. Retrieved 2006-12-13.
  12. ^ Roy S (January 2018). "Soil Arthropods in Maintaining Soil Health: Thrust Areas for Sugarcane Production Systems". Sugar Tech. 20 (4): 376–391. doi:10.1007/s12355-018-0591-5. S2CID 19040885.
  13. ^ Fernandes Correia ME (2018). "Soil fauna changes across Atlantic Forest succession". Comunicata Scientiae. 9 (2): 162–174. doi:10.14295/cs.v9i2.2388 – via Dialnet.
  14. ^ Smith LM (1960-09-01). "The Family Projapygidae and Anajapygidae (Diplura) in North America". Annals of the Entomological Society of America. 53 (5): 575–583. doi:10.1093/aesa/53.5.575.
  15. ^ Carapelli A, Nardi F, Dallai R, Frati F (2006). "A review of molecular data for the phylogeny of basal hexapods". Pedobiologia. 50 (2): 191–204. doi:10.1016/j.pedobi.2006.01.001.
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