Amblycera
{{Short description|Parvorder of lice}}
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| image = Ricinus bombycillae (Denny, 1842).JPG
| image_caption = Ricinus bombycillae (Ricinidae)
from a Bohemian waxwing
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| taxon = Amblycera
| authority = Kellogg, 1896
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Amblycera is a parvorder of chewing lice from the infraorder Phthiraptera. The lice are ectoparasites and spend their entire lives parasitizing their hosts. Amblycera tend to mostly feed on birds, and have specialized anatomy to assist in feeding. The lice undergo a three part process of metamorphosis and survive around thirty days after moulting into an adult. They rely on a combination of skin debris and blood for nutrients to sustain themselves. Amblycera are distributed globally, and are very host–specific.
Classification
Amblycera is currently classified as a parvorder, and it was named by Kellogg in 1896.{{Cite web| website = Psocodea Species File |title = Amblycera Kellogg, 1896 |last1 = Hopkins |first1 = H. |last2 = Johnson |first2 = K. P. |last3 = Smith |first3 = V. S. |url = https://psocodea.speciesfile.org/otus/884594/overview}} Amblycera belongs to the infraorder Phthiraptera, which contains all lice, and is part of the larger order Psocodea, which also contains booklice, barklice and barkflies. Around 30% of all bird lice belong to Amblycera.{{Cite web |last1=T. Atkinson |first1=Carter |last2=J. Thomas |first2=Nancy |year=2008 |title=Parasitic Diseases of Wild Birds |url=https://darwin.biology.utah.edu/PDFs/BC7.pdf |access-date=May 15, 2025 |website=darwin.biology.utah.edu}} A cladogram showing the position of Amblycera within Phthiraptera and Psocodea is shown below:{{Cite journal|last1=de Moya|first1=Robert S|last2=Yoshizawa|first2=Kazunori|last3=Walden|first3=Kimberly K O|last4=Sweet|first4=Andrew D|last5=Dietrich|first5=Christopher H|last6=Kevin P|first6=Johnson|date=2021-06-16|editor-last=Buckley|editor-first=Thomas|title=Phylogenomics of Parasitic and Nonparasitic Lice (Insecta: Psocodea): Combining Sequence Data and Exploring Compositional Bias Solutions in Next Generation Data Sets|url=https://academic.oup.com/sysbio/article/70/4/719/5912026|journal=Systematic Biology|language=en|volume=70|issue=4|pages=719–738|doi=10.1093/sysbio/syaa075|pmid=32979270|issn=1063-5157|doi-access=free}}
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|1=Anoplura
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Characteristics
Like all chewing lice, Amblycera are permanent ectoparasites of their hosts, in that they spend their entire life living off of their individual host.{{Cite web |last1=P. Johnson |first1=Kevin |last2=H. Clayton |first2=Dale |title=THE BIOLOGY, ECOLOGY, AND EVOLUTION OF CHEWING LICE |url=https://phthiraptera.myspecies.info/sites/phthiraptera.info/files/41865.pdf |access-date=May 11, 2025 |website=phthiraptera.myspecies.info}} Almost all Amblycera exclusively parasitize birds. In a section of their throat called the crop, Amblycera contain developed comb structures at the base.{{Cite web |title=Louse {{!}} Description, Features, Life Cycle, Species, & Classification {{!}} Britannica |url=https://www.britannica.com/animal/louse |access-date=2025-05-11 |website=www.britannica.com |language=en}} The structures are used to prevent feathers and other debris from progressing further into the digestive system. All species are wingless, and have a broad head with a pair of mandibles.{{Cite web |title=Order Phthiraptera – ENT 425 – General Entomology |url=https://genent.cals.ncsu.edu/insect-identification/order-phthiraptera/ |access-date=2025-05-11 |language=en-US}} The antennae are broken into three to five joints depending on the species, and they do not have any eyes. Anmblycera also have two small segmented claws at the end of their limbs. Species are small and dorsoventrally compressed, and are host specific in that a single species will parasitize on a single host. They can vary between one and five millimeters long, and range in color from white to black.{{Cite web |title=Chewing louse {{!}} Parasite, Poultry, Livestock {{!}} Britannica |url=https://www.britannica.com/animal/chewing-louse |access-date=2025-05-11 |website=www.britannica.com |language=en}}
= Life cycle =
Amblycera undergo a process of metamorphosis with three stages: Eggs (also known as "nits"), nymph and adult. The process usually takes around two to three weeks on average.{{Cite web |title=Lice |url=https://capcvet.org/guidelines/lice/#:~:text=Once%20the%20egg%20has%20hatched,canis%20and%20F. |access-date=2025-05-11 |website=Companion Animal Parasite Council |language=en}} Eggs are usually 0.8 millimeters long and oval shaped. The eggs also small holes called micropyles that allow for respiration.{{Cite book |last1=Lucius |first1=Richard |title=The Biology of Parasites |last2=Loos-Frank |first2=Briggete |publisher=Wiley |isbn=9783527698561 |publication-date=January 4, 2017 |pages=418 |language=en}} They range in color from yellow to white.{{Cite web |title=Lice-life-cycle |url=https://byjus.com/biology/lice-life-cycle/ |access-date=2025-05-11 |website=BYJUS |language=en}} The nymphs are also yellow to white in color, and undergo a three part process of moulting over the course of a week. After the third nymph moult the lice are considered adults, and will live up to thirty days off of their chosen host.
= Distribution =
Like all lice, Amblycera are distributed in the same locations as their preferred host.{{Cite web |date=2022-02-15 |title=Lice (Phthiraptera) - Factsheet for health professionals |url=https://www.ecdc.europa.eu/en/all-topics-z/disease-vectors/facts/factsheet-lice-phthiraptera#:~:text=All%20lice%20are%20co-distributed,humans%20and%20their%20domesticated%20animals. |access-date=2025-05-11 |website=www.ecdc.europa.eu |language=en}} The lice were likely spread during the original human colonization of various continents when host animals were brought along with them. The most diverse family, Menoponidae, has a high quantity of host-specific species is distributed across multiple continents.{{Cite journal |last1=Kolencik |first1=Stanislav |last2=Sychra |first2=Oldrich |last3=Johnson |first3=Kevin P. |last4=Weckstein |first4=Jason D. |last5=Sallam |first5=Mohamed F. |last6=Allen |first6=Julie M. |date=2024-05-01 |title=The parasitic louse genus Myrsidea (Amblycera: Menoponidae): a comprehensive review and world checklist |url=https://experts.illinois.edu/en/publications/the-parasitic-louse-genus-myrsidea-amblycera-menoponidae-a-compre |journal=Insect Systematics and Diversity |volume=8 |issue=3 |doi=10.1093/isd/ixae007 |issn=2399-3421 |url-access=subscription}} Amblycera have shown a positive correlation between the quantity and diversity of host birds in regions and the quantity and diversity of their own species.{{Cite web |title=Museu de Ciències Naturals de Barcelona: Scientific journals |url=https://museucienciesjournals.cat/en/amz/issue/19-2021-en/checklist-of-chewing-lice-phthiraptera-amblycera-and-ischnocera-of-the-birds-of-peru |access-date=2025-05-12 |website=museucienciesjournals.cat |language=ca}}
Feeding method
Amblycera feed almost entirely on birds. The lice depend on a combination of skin, hair, feathers and blood for food and nutrients.{{Cite journal |last1=Zhang |first1=Yanjie |last2=Rasnitsyn |first2=Alexandr P. |last3=Zhang |first3=Weiwei |last4=Song |first4=Fan |last5=Shih |first5=Chungkun |last6=Ren |first6=Dong |last7=Wang |first7=Yongjie |last8=Li |first8=Hu |last9=Gao |first9=Taiping |date=2024-02-26 |title=Stem chewing lice on Cretaceous feathers preserved in amber |journal=Current Biology |language=English |volume=34 |issue=4 |pages=916–922.e1 |doi=10.1016/j.cub.2024.01.027 |issn=0960-9822 |pmid=38320551|bibcode=2024CBio...34E.916Z |doi-access=free }} They use their mandibles in a horizontal scraping fashion to separate the skin from the bird so that it can be consumed. They also use their claws to grasp onto the feathers of the host in order to prevent the bird from shaking the lice off. They feed on both living and dead cells, as opposed to the closely related ischnoceran lice that feeds exclusively on dead material.{{Cite web |last1=J. Weaver |first1=Haylee |last2=Rózsa |first2=Lajos |title=CONCEPTS IN ANIMAL PARASITOLOGY |url=https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1096&context=parasittext |access-date=May 11, 2025 |website=digitalcommons.unl.edu}} While most ampblyceran lice use mandibles to feed, species in the genus Trochiloecete use two sharp stylets to pierce the skin and consume blood from nearby blood vessels.{{Cite web |title=Amblycera |url=https://www.oxfordreference.com/display/10.1093/oi/authority.20110803095407300 |access-date=2025-05-11 |website=Oxford Reference |language=en }} Amblycera lice tend to parasitize one host before quickly moving onto another one, without staying nearby one that is dead.
Effects
The lice by themselves are not particularly harmful,{{Cite web |title=Bird louse {{!}} Parasitic, Feather-Feeding, Poultry {{!}} Britannica |url=https://www.britannica.com/animal/bird-louse |access-date=2025-05-12 |website=www.britannica.com |language=en}} however depending on the quantity the presence of Amblycera on birds they can cause dermatitis and promote itchiness and scratching.{{Cite web |last1=Clayton |last2=Gregory |last3=Price |year=1992 |title=Comparative ecology of Neotropical bird lice (Insecta: Phthiraptera) |url=https://darwin.biology.utah.edu/PDFs/14.pdf |access-date=May 11, 2025 |website=darwin.biology.utah.edu}} In poultry, the lice can significantly reduce the rate of egg production. Birds with physically damaged bodies are vulnerable to Amblycera infestations due to the reduced ability to remove the lice by themselves. Birds infested with Amblycera also have a reduced ability to attract mating partners.
Families
Amblycera contain seven individual families of parasitic lice:{{Cite web |last=K. Marshall |first=Isabel |title=A morphological phylogeny for four families of amblyceran lice |url=https://phthiraptera.myspecies.info/sites/phthiraptera.info/files/41621.pdf |access-date=May 11, 2025 |website=phthiraptera.myspecies.info}}
- Menoponidae Mjöberg, 1910
- Laemobothriidae Mjöberg 1910
- Ricinidae Neumann 1890
- Boopiidae Mjöberg, 1910
- Gyropidae Kellogg, 1896
- Trimenoponidae Neumann 1890
- Abrocomophagidae Emerson and Price 1976
References
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- {{Commons category-inline|Amblycera}}
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