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#astigmata — Public Fediverse posts

Live and recent posts from across the Fediverse tagged #astigmata, aggregated by home.social.

  1. RE: mastodon.scot/@kim_harding/115

    #Sarcoptes #scabiei var. hominis (#Astigmata, Acariformes) is a skin-#parasitic #mite that feeds on human #epidermal cells. Infection typically occurs via adult, mated #females.The mite has #subspecies found on both #domestic and #wild #animals. The #evolutionary direction was via #humanancestors to humans and from there #spreading first to domestic animals and then to wild animals (see ref).
    © #StefanFWirth 2026

    Reference
    R. W. Currier er al. (2012): doi.org/10.1111/j.1749-6632.20

  2. RE: mastodon.scot/@kim_harding/115

    #Sarcoptes #scabiei var. hominis (#Astigmata, Acariformes) is a skin-#parasitic #mite that feeds on human #epidermal cells. Infection typically occurs via adult, mated #females.The mite has #subspecies found on both #domestic and #wild #animals. The #evolutionary direction was via #humanancestors to humans and from there #spreading first to domestic animals and then to wild animals (see ref).
    © #StefanFWirth 2026

    Reference
    R. W. Currier er al. (2012): doi.org/10.1111/j.1749-6632.20

  3. RE: mastodon.scot/@kim_harding/115

    #Sarcoptes #scabiei var. hominis (#Astigmata, Acariformes) is a skin-#parasitic #mite that feeds on human #epidermal cells. Infection typically occurs via adult, mated #females.The mite has #subspecies found on both #domestic and #wild #animals. The #evolutionary direction was via #humanancestors to humans and from there #spreading first to domestic animals and then to wild animals (see ref).
    © #StefanFWirth 2026

    Reference
    R. W. Currier er al. (2012): doi.org/10.1111/j.1749-6632.20

  4. RE: mastodon.scot/@kim_harding/115

    #Sarcoptes #scabiei var. hominis (#Astigmata, Acariformes) is a skin-#parasitic #mite that feeds on human #epidermal cells. Infection typically occurs via adult, mated #females.The mite has #subspecies found on both #domestic and #wild #animals. The #evolutionary direction was via #humanancestors to humans and from there #spreading first to domestic animals and then to wild animals (see ref).
    © #StefanFWirth 2026

    Reference
    R. W. Currier er al. (2012): doi.org/10.1111/j.1749-6632.20

  5. RE: mastodon.scot/@kim_harding/115

    #Sarcoptes #scabiei var. hominis (#Astigmata, Acariformes) is a skin-#parasitic #mite that feeds on human #epidermal cells. Infection typically occurs via adult, mated #females.The mite has #subspecies found on both #domestic and #wild #animals. The #evolutionary direction was via #humanancestors to humans and from there #spreading first to domestic animals and then to wild animals (see ref).
    © #StefanFWirth 2026

    Reference
    R. W. Currier er al. (2012): doi.org/10.1111/j.1749-6632.20

  6. A striking #character of adult #mites in #Histiostomatidae (#Astigmata) is a highly #sclerotized area on the upper surface of #proterosoma. Its #latticelike #structure forms a #taxonomically relevant #symmetrical #pattern of windows, for which I introduced a #nomenclature in my PhD thesis. This area is a site of #muscleorigins (see #SEM section through a bigger specimen of #Acaridae).
    ©#StefanFWirth 2026

    Please support my work with a coffee
    ko-fi.com/sfwirth

    #pics
    ©S.F. Wirth edit 2026

  7. A striking #character of adult #mites in #Histiostomatidae (#Astigmata) is a highly #sclerotized area on the upper surface of #proterosoma. Its #latticelike #structure forms a #taxonomically relevant #symmetrical #pattern of windows, for which I introduced a #nomenclature in my PhD thesis. This area is a site of #muscleorigins (see #SEM section through a bigger specimen of #Acaridae).
    ©#StefanFWirth 2026

    Please support my work with a coffee
    ko-fi.com/sfwirth

    #pics
    ©S.F. Wirth edit 2026

  8. A striking #character of adult #mites in #Histiostomatidae (#Astigmata) is a highly #sclerotized area on the upper surface of #proterosoma. Its #latticelike #structure forms a #taxonomically relevant #symmetrical #pattern of windows, for which I introduced a #nomenclature in my PhD thesis. This area is a site of #muscleorigins (see #SEM section through a bigger specimen of #Acaridae).
    ©#StefanFWirth 2026

    Please support my work with a coffee
    ko-fi.com/sfwirth

    #pics
    ©S.F. Wirth edit 2026

  9. A striking #character of adult #mites in #Histiostomatidae (#Astigmata) is a highly #sclerotized area on the upper surface of #proterosoma. Its #latticelike #structure forms a #taxonomically relevant #symmetrical #pattern of windows, for which I introduced a #nomenclature in my PhD thesis. This area is a site of #muscleorigins (see #SEM section through a bigger specimen of #Acaridae).
    ©#StefanFWirth 2026

    Please support my work with a coffee
    ko-fi.com/sfwirth

    #pics
    ©S.F. Wirth edit 2026

  10. A striking #character of adult #mites in #Histiostomatidae (#Astigmata) is a highly #sclerotized area on the upper surface of #proterosoma. Its #latticelike #structure forms a #taxonomically relevant #symmetrical #pattern of windows, for which I introduced a #nomenclature in my PhD thesis. This area is a site of #muscleorigins (see #SEM section through a bigger specimen of #Acaridae).
    ©#StefanFWirth 2026

    Please support my work with a coffee
    ko-fi.com/sfwirth

    #pics
    ©S.F. Wirth edit 2026

  11. #Mouthparts in #mites of the #Acariformes are usually normal shaped as typical for #arachnids. The #chelicerae are the feeding organs consisting of digitus fixus and d. mobilis. #Pedipalps have sensing functions with different kinds of #sensoryorgans. In #Histiostomatidae (#Astigmata) the whole #gnathosoma is modified into a complex #filterfeeding organ that creates an #underpressure on #food surfaces.
    © #StefanFWirth Berlin 2026

    Reference
    S. F. Wirth (2023)
    fao.org/fileadmin/user_upload/

  12. #Mites of the #Histiostomatidae (#Astigmata) not only have highly #modified #mouthparts (see photo) that form a #filterfeeding organ, but their #copulatoryposition is also an #evolutionary #modification. Other Astigmata mate back-to-back, while Histiostomatidae have the male riding on top of the female, head over head. See here the dorsal #copulationopening of a #female of #Histiostoma sp..

    ©#StefanFWirth 2025

    Further reading S.F. Wirth ( 2024)
    fao.org/global-soil-partnershi

    SEMphotos ©S.F. Wirth

  13. #Mites of the #Histiostomatidae (#Astigmata, #Acariformes) are adapted due to #evolution to form #species with #small sizes of about 200-400 micrometers in adults. Their thin #cuticles and modified #filterfeeding #mouthparts for #fungus-bacterial #food intake allowed their #radiation within shortliving moist and bacteria/fungus rich habitats.

    ©#StefanFWirth October 2025,

    Photos
    Females of #Histiostoma sp., from #sapropel #mud around gravel pit ponds, #Berlin #Grunewald, 2019, New edit 2025

  14. In #Astigmata #mites #chemosensitive/#tactile interactions take precedence over #visualsenses. #Histiostomatidae (here, #Histiostoma sp., H. feroniarum complex, ex #rottinglemons, #Italy) communicate using various #pheromones/allomones produced by the #opisthonotal #glands. See here a #glandularopening on the upper hindbody #(hysterosoma) of a #female, #SEM.

    © #StefanFWirth, 2025

    Reference:

    Stefan F. Wirth about a lemon mite (2024): fao.org/global-soil-partnershi

    Photos:
    © SFWirth Bln, 2006-25

  15. When #animals #carry other organisms: If it is a regular dispersal strategy it can be #phoresy. When phoretic #mites, such as soil mite #Histiostoma sp. (#Astigmata) here, disperse #fungi themselves, this can be hyperphoresy. The mating adult mites in my #SEM carry #macroconidia, presumably of Ascomycota. Adult mites aren't the phoretic stage, thus they can disperse a fungus only within their limited #habitat.
    ©#StefanFWirth Berlin 2025

    Reference
    S. F. Wirth (2023)
    fao.org/fileadmin/user_upload/

  16. The #complex #mouthparts of #Acariformes #mites. As an example, here is the #SEM image of a non determined #mite from the #Acaridae (#Astigmata) #cut in the area of ​​the #proterosoma, #perspective towards #gnathosoma from #internally. Visible are the complex #muscles that #move the gnathosoma and partly (left) also the first pair of legs. #Photo from my early postdoc times, re-edited in 2024.
    #evolution #Astigmatina

    © #StefanFWirth Berlin 2024

  17. The #complex #mouthparts of #Acariformes #mites. As an example, here is the #SEM image of a non determined #mite from the #Acaridae (#Astigmata) #cut in the area of ​​the #proterosoma, #perspective towards #gnathosoma from #internally. Visible are the complex #muscles that #move the gnathosoma and partly (left) also the first pair of legs. #Photo from my early postdoc times, re-edited in 2024.
    #evolution #Astigmatina

    © #StefanFWirth Berlin 2024

  18. The #complex #mouthparts of #Acariformes #mites. As an example, here is the #SEM image of a non determined #mite from the #Acaridae (#Astigmata) #cut in the area of ​​the #proterosoma, #perspective towards #gnathosoma from #internally. Visible are the complex #muscles that #move the gnathosoma and partly (left) also the first pair of legs. #Photo from my early postdoc times, re-edited in 2024.
    #evolution #Astigmatina

    © #StefanFWirth Berlin 2024

  19. This is the first #freeliving #instar of a #mite from the #Histiostomatidae (#Astigmata, #Acariformes) : named the #larva and being characterized by having only #3pairs of #legs, which is a phylogenetically old character. #Specific and thus #apomorphic for Histiostomatidae is that there is a #dorsalpattern of #sclerites, differing between subtaxa. The photo shows the species #Histiostoma sp. (H. feroniarum-complex) from rotting #lemonfruits in Italy (Sorrento).

    © #StefanFWirth Berlin 2024

  20. The #phoretic #mite #Forcellinia #wasmanni (#Astigmata, #Acaridae), which occurs among other ant species on the ant #Myrmica #rudinodis, develops in the ant #nest. The phoretic #dispersal stage (#deutonymph) is spread by ant workers.
    To do this, I discovered a behavior I call "#pupa #guarding": it attaches to ant pupae and waits in this position until the adult ant hatches.. My video 2015-2023 in reduced quality (size limitations)
    © #StefanFWirth Berlin/Usedom