Blog and online journal with editorial content about science, art and nature.

Tag: artist

The details about snow


In former times, when people lived in a mystic world, where elves, dwarfs, leprechauns and talking wolves did their dreadful state of affairs in the midst of dark and impenetrable huge forests, people thought that even the old trees in the woods had their own thoughts.

Park Rehberge in Berlin

Uncontrollable, sounds, the snorting of the deer, a mysterious hidden, permanently changing shades in a cold and misty twilight.


A forest is only then a forest, when a high concentration of trees is given. Woods bear a great number of species, produce a majority of oxygen in our world; they are huge reservoirs of water and stabilize the ground with their tangles of roots.


Snow consists of ice crystals. Their formation within clouds depends on the presence of ice nucleating particles and temperatures lower – 12°C.

Crystals possess a hexagonal symmetry, being prism-shaped at lower temperatures and dendrite-shaped at higher temperatures.

Temperate deciduous forests hibernate without functional leaves. Most trees throw off all leaves already in autumn to be protected from desiccation in winter frost periods.

Layers of snow are excellent thermal conductors and additionally protect all life underneath from frost damages in the cold season.

Waiting for the spring time

Most life forms hibernate together with their leafless trees. Especially accumulations of deadwood contain remarkable numbers of species, such as insects, spiders, mites or nematodes. Some already begin under their snow cover to prepare themselves for the warmer season.

When all snow is gone, winter colors in red, yellow, brown and some green reappear. Early blossoming plants are already germinating.

Stefan F. Wirth


Stefan Friedrich Wirth is a freelance German biologist, zoologist, evolutionary biologist and acarologist, living in Berlin.

– born in 1972 in the South-West of Germany.

– studies at the FU (Free University) Berlin 1994-2000

– phd thesis at the FU Berlin 2000-2004

– since 2004 research in the fields of systematics, evolution und ecology of mites (Histiostomatidae, Astigmata, Acari)  in cooperation with different international scientific institutions and  videografie/ macro-Videography as documentary contributions, for example to the „arte“-channel documentaries „Voyage sous nos pieds“ by the French director Vincent Amouroux.

selected publications:

Wirth, S. (2003): Das Stammartmuster der Histiostomatidae (Acari) und Beschreibung der durch zwei Männchen-Typen charakterisierten Histiostoma palustre n. sp.. Acarologia 42, 3: 257-270.

Wirth, S. (2004): Phylogeny, biology and character transformations of the Histiostomatidae (Acari, Astigmata). Promotionsarbeit. Internet Publikation, URL:

Wirth, S. (2004): Phylogeny, Morphology and habitats of the Histiostomatidae (Astigmata). Proceedings of the V Symposium of the European Association of Acarologists. Phytophaga, XIV: 389-407.

Wirth, S. (2005): Description of a new species Bonomoia opuntiae (Histiostomatidae, Astigmata) with observations on the function of its eyes. Acarologia, vol. 45, no 4: 303-319. (URL:

Wirth, S. (2005): Transformations of copulation structures and observations on the male polyphenism in the phylogeny of the Histiostomatidae. Internat. J. Acarol., Vol. 31, No. 2: 91-100.

Wirth, S. (2006): Development of the prelarva and larval behavior to open the eggshell in the Histiostomatidae (Astigmata). Abh. Ber. Naturkundemus. Görlitz 78,1: 93-104.

Wirth, S. (2006): Morphology and function of the gnathosoma in the Histiostomatidae (Astigmata). Acarologia,  vol. 46, no. 1-2: 103-109. (URL:

Wirth, S. (2007): Phylogeny and characteristic transformations of the Histiostomatidae. In: J.B. Morales-Malacara, V. Behan-Pelletier, E. Ueckermann, T.M. Pérez, E.G. Estrada-Venegas and M. Badii (Eds.), Acarology XI. Proceedings of the XI International Congress of Acarology: 607-615, México.

Wirth, S. & Moser, J.C. (2008): Interactions of histiostomatid mites (Astigmata) and leafcutting ants. In: M. Bertrand, S. Kreiter, K.D. McCoy, A. Migeon, M. Navajas, M.-S. Tixier, L. Vial (Eds.), Integrative Acarology. Proceedings of the 6th Congress of the European Association of Acarologists: 378-384; EURAAC 2008, Montpellier, France.

Wirth S. (2009): Necromenic life style of Histiostoma polypori (Acari, Histiostomatidae). Experimental and applied acarology. DOI number: 10.1007/s10493-009-9295-6. URL:

Wirth, S. (2010): Food competition and feeding behaviour and its implications for the phylogeny of the Histiostomatidae (Astigmata). – In: Sabelis, M. W. & Bruin, J. (eds.). Trends in Acarology: 37-40.

Wirth S. & Moser J. C. (2010): Histiostoma blomquisti N. SP. (Acari: Histiostomatidae) A phoretic mite of the Red Imported Fire Ant, Solenopsis invicta Buren (Hymenoptera: Formicidae). Acarologia 50(3): 357-371.

DunlopJ. A., Wirth1 S., Penney2 D.,  McNeilA., Bradley3R.S.,  Withers3 P. J.,Preziosi2 R. F. (2011): A tiny phoretic mite deutonymph in Baltic amber recovered by X-ray computed tomography. Biology letters doi:10.1098/rsbl.2011.0923.

Krüger J. & Wirth S. (2011): Life cycle of  Sarraceniopus nipponensis (Histiostomatidae: Astigmata) from the fluid-filled pitchers of Sarracenia alata (Sarraceniaceae). Acarologia 51(2): 259-267.

Koller L., Wirth S. and Raspotnig G. (2012): Geranial-rich oil gland secretions: a common phenomenon in the Histiostomatidae (Acari, Astigmata)? International journal of Acarology 38(5-38): 420-426.

Pernek M.1,2, Wirth S.3, Blomquist S. R.4, Avtzis D. N.5, Moser J. C.4 (2012): New associations of phoretic mites on Pityokteines curvidens (Coleoptera, Curculionidae, Scolytinae). Central European Journal of Biology. Volume 7, Issue 1: 63-68.

Pernek M. (1),  Novak Agbaba S.(1), Lackovic N. (1), Dod(1) N., Lukic I. (2), Wirth S. (3) (2012): The role of biotic factors on pine (Pinus spp.) decline in north dalmatia (croat: uloga biotičkih čimbenika u sušenjuborova (Pinus spp.) na područjusjeverne dalmacije). Šumarski list, 5–6, cxxxvi: 343–354.

Wirth S. (1), Pernek M. (2) (2012): First record of the mite Histiostoma ulmi in silver fir and indication of a possible phoretic dispersal by the longhorn beetle Acanthocinus reticulates. Šumarski list, 11–12, CXXXVI: 597–603.

Wirth S. & Garonna A. P.  (2015): Histiostoma ovalis (Histiostomatidae, Acari) associated with Ips sexdentatus (Scolytinae, Curculionidae, Coleoptera): ecology and mite redescription on the basis of formerly unknown adults and nymphs . International Journal of Acarology DOI: 10.1080/01647954.2015.1050062

WIRTH S., WEIS O., PERNEK M. (2016): A comparison of phoretic mites associated with bark beetles Ips typographus and Ips cembrae from Central Croatia. Šumarski list.

WIRTH S. (2016): Description of developmental instars of Bonomoia sibirica n. sp. (Astigmata: Histiostomatidae) with ecological observations and phylogenetic conclusions. Acarina, December issue.

WIRTH S. F. (2021): Two different forms of cryptic species-complexes in mites of the Histiostomatidae (Astigmata) from bank mud and bark beetle-galleries and their significance for applied biodiversity research. Biologe (ed. Stefan F. Wirth), category : original scientific papers volume 1 (2021; 2022) , 1-7. URL:

WIRTH S. F. (2022): Specific phoretic mites as microclimate originators in special ephemeral soil habitats as presumed co-creators of nutrient-rich soil areas. Poster publication to Global Symposium on Soils for Nutrition, 26/07/2022 – 29/07/2022, by FAO (Food and Agriculture Organization of the United Nations), poster 167.