biologe

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

Tag: biology

Teaching: Ich als Naturalist – Me as a naturalist

Bumble bee Bombus sp. in Berlin, copyrights Stefan F. Wirth 2021/2022
Honey bee Apis mellifera in Berlin, copyrights Stefan F. Wirth 2021/2022
Deutonymphs of the microscopically tiny mite Schwiebea cf. eurynymphae (Acaridae, Astigmata) formally attached to beetle Phosphuga atrata under the bark of felled tree trunk of Tilia platyphyllos in urban park Rehberge in Berlin, copyrights Stefan F. Wirth, 2021/2022
Larvae of beetle Oryctes nasicornis from Italy with associated gamasid mites under studio light conditions, copyrights Stefan F. Wirth, Berlin 2016/2022
Land crab Metasesarma obesum under studio conditions, copyrights Stefan F. Wirth, Berlin 2017/2022

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Ich biete Unterricht, Förderkurse, Vorträge und Fortbildungskurse zu den Themen Naturkunde, Naturschutz, Artenvielfalt, Ökologie, Klimaschutz und Evolution an sowie Unterricht oder Vorträge zur Naturfotografie oder der Naturfilmerei. All dies entweder auf Honarbasis oder via Anstellung. Bitte entnehmen Sie weitere Informationen meinem Menüpunkt zum Thema Unterricht und Lehre. Selbstverständlich verfüge ich über Qualifikationsnachweise zu meinen diversen bisherigen Lehrtätigkeiten sowie meine fachliche Kompetenz. Bitte beachten Sie hierzu auch meinen Menüpunkt Curriculum Vitae.

Doch was sind eigentlich meine Themengebiete? Im Folgenden finden Sie interessante Fragestellungen aus meinen Kompetenzbereichen.

Was ist ein Ökosystem? Welche Ökosysteme sind gut untersucht, welche eher nicht? Wie gut kennt man die Artenvielfalt von Mikro-Lebensstätten in Deutschland, und was ist über deren biologische (ökologische) Zusammenhänge bekannt? Was ist denn eigentlich eine Art, was sind denn dann Zwillingsarten, und was versteht man gar unter einem Artenkomplex (kryptische Artengruppe)? Ist das Aussterben von Arten ein normaler Bestandteil der Evolution oder ist das Aussterben einer Art immer zwingend ein alamierender Hinweis auf eine (evtl. menschengemachte) Naturkatastrophe? Wieviele Arten aus allen Organismengruppen weltweit kennen wir, und wieviele in etwa kennen wir noch nicht? Warum kennen wir viele Arten, sogar in Deutschland, noch immer nicht? Wie erkennt man neue Arten, und wie ist eine sogenannte Artbeschreibung aufgebaut? Ist der Mensch eine Tierart, und wo im Stammbaum der Tiere ist er dann anzusiedeln?

Warum sind ein Wald, ein Teich oder eine Wiese Orte für interessante Entdeckungen, und zwar insbesondere auch für Kinder? Was lebt denn da, und wie ist es an seinen Lebensraum angepasst? Was haben unterschiedliche Arten in solchen Lebensräumen eigentlich miteinander zu tun? Und wie beobachtet man Tierverhalten am besten? Wie dokumentiert man es aussagekräftig, um sein Wissen später mit Freunden oder über soziale Netzwerke teilen zu können?

Wie kommt es zum sogenannten Global Warming, der globalen Klimaerwärmung? Wie können wir sie nachweisen? Warum ist sie zu einem beträchtlichen Teil menschengemacht? Und welche Auswirkungen haben Klimaerwärmung und die Ausbeutung natürlicher Ressourcen (Energiespeicher, Rohstoffe, wie zum Beispiel Tropenholz) für die Zukunft der Menschheit und die Artenvielfalt auf unserer Erde. Welche Auswege erhofft man sich? Woran wird derzeit gearbeitet?

Was benötigt man zur Naturfotografie, was, wenn man zusätzlich oder alternativ auch noch auf gutem Niveau filmen möchte? Was ist grundsätzlich wichtiger: Das Equipment oder das Bild, das zuvor im Kopf des Fotografen oder Filmers entsteht? Muss taugliches Equipment immer ultra-teuer sein? Welche Software eignet sich am besten zum Editieren? Was genügt dabei den Ansprüchen von Anfängern, was benötigen Fortgeschrittene und Profis? Wie filme oder fotografiere ich draußen in der Natur? Wie hole ich stattdessen die Natur in mein Fotostudio und inszeniere sie dort so, dass es aussieht, als habe man im Freien gearbeitet?

Dies sind alles mögliche Themen, die in meinem Unterricht, meinen Kursen oder Vorträgen vertieft werden können. Beliebige weitere Fragestellungen aus den Bereichen Naturkunde, Biologie, Ökologie und Evolution arbeite ich gerne für Sie aus.

I offer lessons, remedial courses, lectures and advanced training courses on the subjects of natural history, nature conservation, biodiversity, ecology, climate protection and evolution, as well as lessons or lectures on nature photography or nature filming. All this either on a fee basis or via employment. Please see my menu item on the subject of teaching for further information. Of course, I have proofs of qualifications for my various previous teaching activities as well as my professional competence. Please also note my menu item Curriculum Vitae. 

But what are my topics? In the following you will find interesting questions from my areas of competence:

What is an ecosystem? Which ecosystems have been well studied and which not? How well do you know the biodiversity of micro habitats in Germany and what is known about their biological (ecological) relationships? What is actually a species, what are sibling species, and what is meant by a species complex (cryptic species group)? Is the extinction of species a normal part of evolution or is the extinction of a species always an alarming indicator of a (possibly human-made) natural disaster? How many species from all groups of organisms worldwide do we know, and roughly how many do we not yet know? Why do we still not know many species, even in Germany? How do we recognize new species and how is a so-called species description structured? Are humans an animal species, and if so, where do they belong in the animal tree?

Why are a forest, a pond or a meadow places for interesting discoveries, especially for children? What lives there and how is it adapted to its habitat? What do different species actually have to do with each other in such habitats? And what is the best way to observe animal behavior? How can you document it meaningfully so that you can later share your knowledge with friends or via social networks? 

How does the global warming come about? How can we prove its existence? Why is it largely human-made? And what are the effects of global warming and the exploitation of natural resources (energy stores, raw materials such as tropical wood) on the future of humanity and biodiversity on our planet? What exits to avoid emergency situations are we hoping for? What are scientists currently working on to ensure a healthy human future? 

What do we need for nature photography, what if we also want to film at a good level in addition or as an alternative? What is fundamentally more important: the equipment or the image that is created in the head of the photographer or filmmaker? Does suitable equipment always have to be ultra-expensive? Which software is best for editing? What meets the requirements of beginners, what do advanced and professionals need? How do we film or take photos outdoors in nature? Instead, how do we bring nature into our photo studio and stage it there in such a way that it looks as if we were working outdoors? 

These are all possible topics that can be deepened in my teaching, courses or lectures. I would be happy to work out any other questions from the fields of natural history, biology, ecology and evolution for you. 



all copyrights Stefan F. Wirth Berlin 2022

Mate guarding of a juvenile female in mites of the Histiostomatidae (Astigmata, Acariformes)

Male of Histiostoma sp. guards a female tritonymph, copyrights Stefan F. Wirth 2005-2022

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A strategy to avoid male competition for females

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Some mites of the Histiostomatidae practice so-called mate guarding of subadult females in order to have an advantage in the intraspecific competition between males for adult females. My SEM image shows a male on top of a female, which is still inside its tritonymphal cuticle. Inside the tritonymphal cuticle, the adult female is already developed and shortly before hatching. Before hatching, the legs of the new instar are folded under the body side. The new second leg on the right side is visible in the SEM, because the weak cuticle of the old leg broke off. This strategy to avoid sexual competition is quite common with Histiostomatidae. Due to insufficient mite material and not longer available clear ecological data, I determine the long haired adults of my old SEM series with caution as Histiostoma sp., it seemingly was found around sap flux on a tree trunk in Berlin. The species is not identical with Seliea pulchrum (= Histiostoma pulchrum), typically known from sap flux. The distance between the male legs 1 and 2 in the photo is about 0.1 mm. These SEM objects were seemingly chemically dried for the scanning electron microscopic procedure. The photos were taken around 2005 with an older SEM at FU Berlin. © Stefan F. Wirth Berlin 2022

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 ISSN 2750-4158

Stefan F. Wirth, acarologist, freelancer, Berlin, Germany

Citation: 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: https://biologe.wordpress.com/2021/12/31/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

Abstract

In biodiversity research, knowledge of species numbers is the basis for planning environmental protection and climate research. However, the taxonomic work is made more difficult by cryptic species complexes in the world of organisms. Careless determinations of similar species must be prevented. For a beter understanding, examples from different animal groups are given. Using two species complexes of the mite taxon Histiostomatidae (Astigmata), two different forms of cryptic species complexes are presented in detail. Based on three species from a group associated with bark beetles, an example of a species complex is presented in detail, in which all stages of development look confusingly similar to one another. On the other hand, four species of mites from the bank mud of standing waters can only be confused with one another on the basis of their phoretic dispersal stage (deutonymph), while the adults differ distinctly. The meaning of such species complexes is discussed in the evolutionary and applied context. It is critically pointed out that too few specialists are funded worldwide and few taxonomists have to work too quickly, so that there is a risk of cryptic groups of species not being taken into account in surveys.


Keywords: cryptic species groups, evolution, biodiversity research, Acariformes, Histiostomatidae, Astigmata, phoresy, Histiostoma piceae, Histiostoma Scheucherae, Histiostoma piceae, Histiostoma ulmi, Histiostoma palustre, Histiostoma litorale, male morphology, SEM, Histiostoma maritimum, Scolytinae, Carabidae, sapropel


Introduction


Biodiversity research is an essential fundament for disciplines like climate research and climate changes and thus contributes to an understanding about, how we humans need to treat our own environments. A main aspect of biodiversity research besides species monitoring is the evaluation of how many species we have. Specialists need to recognize and scientifically describe new species, especially, when it for example comes out that a complex of very similiar species contains more species than expected before (e.g. Laska et al. 2018). In tendency researchers in the field of biodiversity focus most on vertebrates in temperate regions and generally less in invertebrates (Titley et al. (2017).

The number of recently existing species in numerous cases is still unknown, especially in taxa of small organisms, such as mites. Due to a lack of specialists and due to a lack of fundamental research fundings, relatively much is known about direct pests of human sources, such as Varroa or Tetranychidae mites. But within the major clade Acariformes, ecological contexts and numbers and distribution of species of some free living taxa of Prostigmata and Oribatida/Astigmata are still an open field, even in Central Europe, e. g. Germany (Wirth, 2004).

This is despite the fact that for example phoretic mites, which use other arthropods as carriers for dispersal, can have highly complex relationships with their phoretic hosts, thus being of interest from the evolutionary, the ecological and even an applied point of view. The latter is discussed for example in context with different bark beetles, which their mites might affect by acting as vectors for fungus spores (Klimov & Khaustov, 2018).

Cryptic species complexes are a topic that is currently being widely dealt with in science. Such species complexes are characterized by the fact that they are difficult or impossible to distinguish morphologically. However, they can be clearly differentiated from one another using barcoding (e.g. Kameda et al, 2007), behavioral or ecological studies. Crossing experiments are a frequently used ecological method. Because according to the biological species concept, individuals of different species either cannot be crossed with one another or the offspring of such a hybridization is not fertile (e.g. Sudhaus & Kiontke, 2007).

Crossing experiments are particularly suitable for the investigation of cryptic species complexes in species that have a rapid life cycle and, due to their small size, can be accommodated well in standardized conditions. Such organisms are, for example, free-living nematodes of the Rhabditidae (e. g. Sudhaus & Kiontke, 2007) or mites of the Histiostomatidae (e.g. Wirth, 2004).

The cryptospecies phenomenon, which means that closer investigations show that animals once attributed to the same species actually represent several species, can in principle occur in the entire animal kingdom and in plants and fungi too (Shneyer & Kotseruba, 2015). Previously known subspecies are often given their own species status as a result. One example are the two monitor lizard species Varanus niloticus and V. ornatus (e. g. Böhme & Ziegler, 2004).

In this monitor lizard research mainly ecological differences to V. niloticus have been studied. As one of the results, V. ornatus does not have a diapause in summer, which is a distinct difference to V. niloticus (Böhme & Ziegler, 2004).
As an unusual phenomenon, a case of parthenogenesis was even observed in V. ornatus, but not in V. niloticus (Hennessy, 2010) so far. However, morphological differences between these two monitor lizards were known even before, for example relating to aspects of the dorsal drawing. But the authors named above were able to provide evidence that these morphological differences do not occur gradually, as orgininally assumed, but rather distinctly.

Another example of two sibling species (the most simple form of cryptic groups) that have been identified as different species by molecular biological studies are Homo sapiens and H. neanderthalensis (e.g. Prüfer et al., 2014). Originally it was assumed that H. neanderthalensis was a subspecies of H. sapiens. This is for example supported by the proven cultural exchange between the two species and the great morphological similarity. In the meantime, however, morphological findings such as the morphology of the nasal duct of the Neanderthal man have also supported the genetic findings (Márquez et al., 2014). However, very recent studies show that Neanderthal genetics have entered the lines of H. sapiens (Hajdinjak er al., 2021). As a result, both forms have crossed and produced fertile offspring. It remains to be seen whether this will possibly dismiss the concept of two species again.

Since the aim of all studies of cryptic species complexes is to find distinctive differences in the areas of morphology, ecology or barcoding (or all approaches together) that distinguish one species from all others, ultimately clearly definable, very closely related species remain in case of successful studies.

If the cryptic organisms are members of an organism-socialization, such as parasites and their hosts, the idea that a proven host specificity can be an indicator for a certain species of a cryptic complex is obvious. In fact, Wirth et al. (2016) for example postulated a host specificity for the phoretic mite Histiostoma piceae and its hosts, the bark beetles Ips typographus and I. cembrae. Nevertheless, relationships between associated species are usually not studied extensively enough to be able to unequivocally identify certain species on the basis of for example their hosts (Wirth, 2004).

Since cryptic species represent nevertheless separate species despite their extraordinary similarity, they are subject to the species concepts. As a result, they form different niches and can therefore appear sympatric in the same living space (e. g. McBride et al., 2009). This makes it difficult for biodiversity researchers and systematics to investigate the real numbers of species in such habitats.

If, instead, cryptic species are not sympatric, but distributed in adjacent areas, this can for example indicate that an allopatric species formation has either not been completed for a long time or is even still in the process of speciation (e. g. Gollmann, 1984).

Animal species that have different developmental stages can appear cryptic, i.e.  being morphologically confusingly similar, with regard to all these developmental stages, such as for example certain phoretic free-living nematodes, which then additionally have to be studied ecologically or genetically (e. g. Derycke et al. 2008).

Other species can hardly be distinguished morphologically with regard to a certain developmental stage, which is particularly common, but differ distinctly in other developmental stages, which are more difficult to find. Very similar looking lepidopteran caterpillars of sibling species (e. g. Scheffers et al. 2012) can be more commonly available than their adults, which might be easier to distinguish.

As a specialist for mites of the family Histiostomatidae (Astigmata, Acariformes) I will in my further argumentation refer to my biodiversity studies on these mites and explain the difficult situation for describers of new species based on several specific histiostomatid species, some being phoretically associated with bark beetles and others associated with different coleopterans from muddy sapropel-habitats around ponds in Berlin/Germany.
In connection with these cryptic groups of species, reference should be made to the applied difficulties in connection with biodiversity research. I am referring to the fact that, for a variety of reasons, often only a certain juvenile stage (deutonymph) is used for species descriptions (e. g. Klimov & Khaustov, 2018 B), although cryptic species can occur sympatricly in the same habitat and in many cases not be sufficiently differentiated from one another on the basis of just this one stage.

In Histiostomatidae as in most Astigmata taxa, the deutonymph (in older publications hypopus) represents the phoront, being adapted morphologically and behaviorally in getting dispersed by insects or other arthropods. This instar has no functional mouth, possesses a ventral suckerplate to attach to its carriers and a thicker sclerotization against dehydration. The deutonymph is often collected together with its phoretic host. Bark beetle traps are for example a common source, where dead deutonymphs still on their hosts come from and are subsequently forwarded to acarologists, who then are of course unable to create a mite culture in order to have also adult instars available for species descriptions  (e. g. Klimov & Khaustov, 2018 B) and other taxonomic purposes. This paper shall clarify, why it is instead necessary for a clear species determination to have the deutonymph and additionally at least adults available.

In this publication two cryptic species complexes from the taxon Histiostomatidae (Astigmata) are presented as result of my original scientific work. On the one hand morphologically very similar representatives of the Histiostoma piceae-group, which are originally associated with bark beetles (Scolytinae), on the other hand similar looking representatives, which are bound to insects in the area of ​​the banks of ponds with digested sludge (sapropel). It needs to be emphasized in that context that those herewith introduced two cryptic clades are phylogenetically not closer related to each other.

The presented bark beetle mites (chapter 1 in results) can only be distinguished morphologically by very gradual characteristics, in terms of phoretic deutonymphs as well as in terms of adults. However, there is a tendency towards host specificity (e.g. Scheucher, 1957), which is why there could be a permanent spatial separation of the species despite common occurrence in the same region.

The mites from the sapropel in the area of ​​the pond banks (chapter 2 in results) are presented on the basis of a certain area in Berlin (Germany), where they appeared sympatric. Unlike the bark beetle mites, they are morphologically clearly distinguishable with regard to the adults, but have morphologically very similar deutonymphs, which essentially only differ from one another in degrees.

Based on the representatives of two different cryptic species groups presented in this work, it should be shown that a sufficient range of morphological features for systematic and taxonomic differentiation and characterization of species can only be available if at least two developmental stages of a population can be studied. It is also pointed out that high-resolution optical methods can uncover a possibly systematically relevant variety of morphological features that would otherwise remain hidden. It is suggested that a suspected host specificity cannot always be used to differentiate between very similar species and that cryptic species can be found sympatricly on the same host as well as in the same habitat. The main aim is to show that there is a risk of confusion and a risk of underestimating the existing biodiversity if only the deutonymph is used for taxonomic purposes, just because it is for example easily available, when the host is captured. Nevertheless species descriptions based only on the deutonymphs are unfortunately still surprisingly common.

Due to the lack of sufficient research fundings and a corresponding decrease of experienced specialists, trends to remarkably simplify determinations and species descriptions are about to manifest themselves. Non specialists or less experienced acarologists increasingly try to recognize or describe new species based on the availability of deutonymphs only, because these phoronts are often easily accessible as bycatch of entomological material. It is mistakenly assumed that faster procedures could accelerate the level of scientific knowledge about the biodiversity of astigmatid mites (Wirth, 2004).


Material and Methods


Chapter 1 is an illustration of the current state of my research about a cryptic bark beetle-associated group of species. Problems and questions are additionally shown both on the basis of existing, in part own, literature. Chapter 2 is about four species of Histiostomatidae that were recorded from an old gavelpit area in the urban Berlin forest Grunewald, named „Im Jagen 86“, located 52° 29′ N, 13° 14′ E. This chapter focuses specifically on Histiostoma maritimum, collected between 2002 and 2012 (and also between 1999 and 2000 during my diploma thesis). Besides H. maritimum three other species were found in the same area and habitat: Histiostoma palustre, collected once via deutonymphs from a beetle of Genus Cercyon in 2002 and reared in culture over about two years on moist decomposing potato pieces, Histiostoma litorale, isolated as adults from sapropel mud once in 2002 and Histiostoma n. sp., reared only one generation long from adults to adults in 2019, inside sapropel-mud samples with moss growth and moist decomposing potato pieces.

Mites of H. maritimum were collected as deutonymphs on the beetles Heterocerus fenestratus (rarer on Heterocerus fusculus) and Elaphrus cupreus from sapropel around two ponds in the named area. After different experiments, mites developed successfully on beetle cadavers on 1.5 % water agar in Petri dishes (diameter 5 cm) at room temperature (ca 20°C, summer 2002). Three cultures (one cadaver of C. elaphrus and twice each time two cadavers of H. fenestratus) were observed over a period of about three weeks (additionally small pieces of beef heart were added to all these cultures to maintain suitable food sources). Adult mites were stored in 80 % ethanol for about 5 days and then critical point dried for SEM studies. Photos were taken by an analogous medium size camera via a Philips SEM 515 and later developed. Still unpublished copies from 2002 were scanned in a high 600 dpi solution and as tiffs via a CanoScan Lide 2010 in 2021. Restauration and picture quality improvement were performed via Adobe Lightroom. The areal panorama of the former multiple pond area was captured in September 2018 via a Dji Mavic Pro drone at a height between 30 and 50 m and subsequently modified into black and white.

Setal nomenclature follows Griffiths et al. (1990).



Results:

Seiten: 1 2 3 4 5 6 7

Berlin: Arthropod diversity in 2020 (Corona year)

I documented my nature excursions in 2020 via photography and videography with a special focus to animal macros (outside in the field) and to drone flights. There is also an underwater scenery existing. Most footage was recorded in the area between villages Lübars and Rosenthal in Northern Berlin, close to the nature refuge „Tegeler Fliess“.

The area is characterized by fields, meadows and forest parts and lays along the former GDR wall, today being a hiking and biking trail. Due to a connected mosaic of different ecological habitats, a remarkable biodiversity can there be found, even despite of the worldwide species‘ extinction based on a mostly human made global warming.

My videographic review of the second part of the Corona-year 2020, focussed on arthropod life on meadows in Northern Berlin, all copyrights Stefan F. Wirth

Some few sequences were recorded in other parts of the green city Berlin, namely in the park of the Charlottenburg Palace (beginning sequences of the video) and in urban park Rehberge und Plötzensee (the leaf beetle Galeruca tanaceti in Plötzensee and the scarabaeid beetle – systematically related to genus Cremastocheilus- in Rehberge). Crematocheilus (Cetoniinae) is a genus of myrmecophilous beetles. My individuals were not yet determined, Their existence in Berlin might be even of scientific interest. As putative phoretic vector (to carry mites for their dispersal), they are at least of interest for me, although the studied three beetle individuals did not carry mites at all. The beetles were all found in front of an ant nest intrance (Lasius niger) along the roots of an oak tree in park Rehberge.

As my scientific/ photographic/ videographic excursions happened in exactly that year, 2020, in which the normal human life came worldwide totally out of order based on the covid-19 pandemic, I decided to add this topic to the concept of my video. The video presents nature footage from my visit in the correct seasonal order, beginning with May and June, followed by July, then September/October. In front of each of those months-blocks, I added at that time some important recent news headlines about the corona-pandemic. I named these written parts „corona calendar“. The few December sequences are only dedicated to human street life, showing Berlin in the total lockdown phase, being filmed in black and white (with red recognition).

Berlin, 2 January 2021, all copyrights Stefan F. Wirth

Biodiversity research in the US, is the so called American Way always a good basis?

A collegue from the field of entomology recently wrote me his impressions about the situation of scientific fundings in the western world, as he travels around and stays with each of his feet in another country. He said that everybody knows about the importance of the biodiversity on earth and that consequently everybody agrees that research on the biodiversity deserves to be funded. But he continued that this does not mean that the same people would agree that biodiversity research requires experts and that experts would even need to be paid. Thus many of his former students in the US or Germany need to survive with temporary jobs other than their expertises would require.

But also an international unbalance of financial resources, available for fundamental research in entomology or for example acarology (my discipline) can lead to experts being sorted out, although they would be urgently needed. The focus, based on the considered eligibility of research, changed withing the last 25 years. As before Germany was a hotspot for high-quality research in the fields of evolutionary biology, systematics and biodiversity research, that focus of interest is now located in the USA. They invest more money into these sciences than all European countries together.

This can additionally have consequences for the quality of such kinds of research. It is no secret that the general educational level in the US is at least in some areas comparably low, many people don’t speak foreign languages, they often don’t travel abroad, and they live in midst of a mentality, which says „America first“. Biodiversity research would in the old German world of science regularly be connected with many „but consider that…“ conditions. The American way, in some cases, might want to have it easier. They might say: what’s the problem? What do they want to have? Yes, right, they want the numbers of all discovered species. They ask for numbers, thus we do our best to give them numbers, as fast as possible.

Some privileged US-researchers might even misuse their financial power to decide, who in other countries is and who is not. But I say in a rhetoric „you“: Use your fundings to involve as many suffering experts from abroad as possible, instead of center too much work and responsibility on yourself, you won’t have enough time due to too many species, which still need to be discovered and described.  Don’t work too fast and don’t risk to become too superficial. Each species deserves time. Share the work with others and make science benefit from the different kinds of backgrounds in different areas of the world.

 

Amsterdam_027

A mite of the Histiostomatidae, found in Amsterdam in its original substrate as example for the topic „Acarology“

 

All copyrights (also of SEM photo): Dr. rer. nat. Stefan F. Wirth, Berlin July 2020

Mite Histiostoma piceae

The mite Histiostoma piceae Scheucher, 1957 is a member of the mite family Histiostomatidae (Astigmata, Acariformes). Scheucher discovered the mite based on all instars from spruce, infected by the bark beetle Ips typographus. She collected her samples in Regensburg, Höbing (bei Roth) and Harz. Scheucher reared her specimens on potatoes and bran, but describes that her cultures did grow well only to some degree.

According to her findings,  phoretic carrier (hosts) is the bark beetle species Ips typographus, she also found deutonymphs rarely on some staphylinids. She discovered that free living non-deutonymphal stages develop on fresh detritus, while deutonymphs appear only on old detritus („after it was for a longer time removed from the trees“, „wenn der Mulm einige Zeit aus den Bäumen entfernt ist“). I could like Scheucher culture the mites on potato, but a bit better in their original gallery substrate. Under laboratory conditions, they indeed did not rear very well in both kinds of cultures.

I collected H. piceae between 2000 and 2004 once from a wooden log infested by I. typographus in Berlin, then got access to microscopic slides from Europe in the collection of John C. Moser (Louisiana, USA) in 2007 and 2009, then I collected samples from Ips typographus and I. cembrae in Central Croatia (publication Wirth, Weis and Pernek, 2016) and found out that H. piceae is not restricted to I. typographus, but also to its sibling species I. cembrae. I finally collected the mite from I. typographus galleries between 2015 and 2016 in Western-Siberia near the city Tyumen.

I repeatedly observed deutonymphs of H. piceae under natural conditions (bark samples directly after the excursions) to develop in very high numbers, then attaching to all available arthropods nearby, smaller bark beetle species and numerous bigger mites of different groups, such as for example oribatids.

Published recordings of H. piceae from other bark beetles than I. typographus and I. cembrae are doubtful and need to be named Histiostoma cf. piceae. In some cases with I. typographus additionally present, I interpret the mites to have switched from their regular carrier (host) to an adjacent gallery of e.g. another smaller bark beetle species. In other cases, the existence of similar looking species new to science needs to be tested. In cases of determinations by non specialists from bark beetles other than the above mentioned two beetle species, it needs to be assumed that these people could not differ between similar mite species, such as Histiostoma trichophorum Oudemans, 1912, Histiostoma ulmi Scheucher, 1957 or Histiostoma crypturgi Scheucher, 1957.

 

I never before published the full set of SEM and light microscopic photos from these  times (except of my article about host specificity). In this explicite photo publication here on my homepage, I herewith publish SEM-photographs, objects sputtered with gold, which might be not unique to science, but very rare.

Any subsequent research on this mite in Europe is not happening (a few not too relevant findings are published by a former Russian colleague). Reason is that modern science does not understand, especially not in Germany, that fundamental research in applied fields is worth to be funded. It is for example known that deutonymphs of different mite species on bark beetles regularly carry fungus spores (different fungus species, just sticking on the mite’s cuticle), discovered by John C. Moser and confirmed by several of my own publications. This phenomenon is still not closer studied. Fungus transport into bark beetle galleries can influence the micro climate there.

 

 

Male and female of Histiostoma piceae, A venter of male, B dorsum of male, C mouthparts with Digitus fixus, D dorsum of female, E side-frontal view to female; Berlin 2002-2020, copyrights Stefan F. Wirth

 

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Deutonymph of Histiostoma piceae in ventral view, collected in Western Siberia, 2015 – 2016, copyrights Stefan F. Wirth

 

Systematics: Histiostoma piceae is according to my phd thesis from 2004 and according to my more recent research findings a member of a clade (monophylum) within Histiostomatidae with most species associated with bark beetles (Scolytinae) or other bark inhabiting coleopterans; these phylogenetic findings are based on morphological characters.

Mite Histiostoma maritimum

The mite Histiostoma maritimum Oudemans 1914 is a member of the mite family Histiostomatidae (Astigmata, Acariformes). Oudemans discovered the mite based on its deutonymph only from a Dutch island. The German acarologist R. Scheucher found the species in 1957 in mud at the riverside of Regnitz and for the first time could rear H. maritimum and was able to redescribe it by its adult stages, especially females look morphologically conspicuous due to a sclerotized cuticula shield around its copulation opening. She reared her specimens on potatoes, mud and bran, but describes that her cultures did not grow well.

Phoretic carrieres (hosts) are beetles of genus Heterocerus, some carabids and according her findings also rarely some staphylinids.

I discovered H. maritimum between 2000 and 2004 repeatedly in sapropel around ponds in an old gravel pit area in Berlin, forest Grunewald, named „im Jagen 86“. They were mainly attached to the beetles Heterocerus fenestratus and Heterocerus fusculus, but could regularly also be found on the carabids Elaphrus cupreus and Bembidion sp.. I could several times rear the mites, like Scheucher almost unsuccessfully on potatoes, but well on cadavers of their carriers. I thus reconstructed a so called necromenic life-strategy for H. maritium. This means that a phoretic stage ascends a carrier, but never leaves, instead it awaits the carrier’s natural dead to develop on its cadaver (published in my phd thesis, online, 2004).

I will not publish my full set of SEM photos from earlier times here. Some photos will be saved for one of my upcoming paper submissions in scientific and peer-reviewed journals. In this photo publication here on my homepage, I at least publish some interesting SEM-photographs, based on objects sputtered with gold and a subsequent critical-point-drying procedure.

Adults of Histiostoma maritimum: A left male, right female, B, C, copulation opening, D dorsal view to female with mouthparts and copulation opening

Systematics: H. maritimum shares morphological characters of deutonymph (setation, apodemes) and adults (mouthpart details, shape of Digitus fixus) with species like Histiostoma feroniarum, H. insulare, H. litorale, H. palustre, H. polypori, H. myrmicarum. This might indicate a separate clade, but according to the old findings in my phd thesis, also a paraphyletic grouping including these species is thinkable.

Copyrights Stefan F. Wirth, 10 June 2020

When elbows are used in the world of science

I was part as acarologist and natural scientist in a 2011 scientific paper about a mite preserved as fossil in amber, which was analyzed using the X-ray computed tomography and determined systematically on a family level. In this time, this scientific publication had a remarkable impact in international scientific media, because it seemed, as if this mite was the smallest animal ever visualized via CT on a high quality level.

 

Strange behaviors of so called „colleagues“?

 

The technical work was performed by technical scientists in Manchester UK. The natural scientific analyses was performed by me as the only European specialist for the mite family Histiostomatidae. But I noticed already in the time period of  this publication that there were strict tendencies by the so called „colleagues“ to mention my name as less as possible, this concerned the drafting of international media releases and also a poster presentation (my name was added days later) and an online abstract on a conference in Berlin. The corresponding poster was even awarded, but I got my award certification only after demanding explicitly for it. I much later, when I decided to complain officially at the Museum of Natural Sciences in Berlin, needed to learn that I was not even considered as one of the first authors. I didn’t notice that before, because the former „colleague“, Dr. Jason Dunlop, curator at this museum, was mentioned in the original citation with 1) after his name, me too. Thus I interpreted this as a double-first-author-ship. It then came out that the „1)“ only indicated the same scientific address, because I was in that time officially a volunteer at the MFN in Berlin.

 

Mite in an amber fossil, made visible by using the x-ray computed tomography, acarological work: Stefan F. Wirth

 

The work of a scientific specialist: here an acarologist

 

The question must be: Who is needed to scientifically interpret three dimensional photos of an amber fossil, in this case the deutonymph of a mite of the Histiostomatidae? A specialist for this taxon is needed, who is able to perform scientific drawings, based on the photos. He first needs even to decide, which of the photos are showing details of scientific relevance. While drawing, the specialist must distinctly recognize single microscopic structures, so that all these structures can be clearly separated from each other including all borders or gaps between single components. The scientific term is „homologisation“. Homologisation means: comparing single structures with (phylogenetically) equivalent structures of other (related) species. As there were not more fossils available, the homologisations needed to be based on recent mites. Thus the specialist must have a very competent knowledge of a high number of species from this family. To reach that level requires hard work over many years. I had the necessary level and found character details in the fossil, which were fitting to recent members of mites of the Histiostomatidae. But it’s of course not enough to discover such homologous structures. They must be made visible for every reader of the scientific paper. Thus the drawings need to be correctly labelled, which requires careful morphological studies. Then a detailed description needs to be written. But that is far not enough. Readers of a scientific paper are usually no specialists. That’s why they need a written introduction, in which the summary of the general recent knowledge of a mite group needs to be presented. And after all that they even expect you to discuss your results. It’s an own chapter, subsequent to the result descriptions.

The discussion chapter also requires a maximum of specialized competence. Some researchers even say that this is the first part of a paper that they read as it puts the results into a general scientific context based on arguments, mostly according to the principle of the most economical explication. Conclusions in the discussion part have usually the character of theories based on the facts, which the paper could contribute. Topics of a discussion part in such a paper as ours are systematic conclusions, the discussing of homologisation problems and also the formulation of a possible relevance for the recent scientific knowledge and also the future scientific importance of these new findings.

This all is, what I as a specialist needed to do. I additionally contributed one of my photos of a recent mite for comparative reasons and captured a stereomicroscopic photo of the mite fossil to demonstrate, how much the CT could improve the visible details of the amber fossil. I guess I did quite a lot, the other part was overtaken by the technical colleagues in Manchester. They needed to explain their technical situation and also needed to discuss their ideas about the meaning of their CT-technology for the future of science, focussed also on work with amber fossils.

 

Contributions of different authors to a scientific paper

 

To be honest I don’t remember, where there was still space left for content issue contributions by Dr. Dunlop. But he did some organizational stuff, he collected the contributions from the UK colleagues and me, he arranged the photo table via a graphic software based on the photos, which I had determined as scientifically relevant, and he was the so called corresponding author (I allowed him, because he is an English native speaker). That means, he submitted the final paper to the journal and communicated with the editors. Of course reviewers always ask for revisions. That was then mine and the technicians job again.

It is common that corresponding authors represent automatically the first authors of a paper. But it is not mandatory. I for example once was the corresponding author of a paper, which was based on a bachelor thesis that I (in major parts) supervised. I despite of my in fact major authorship regarding the scientific paper itself and my additional corresponding activities let her (the student) the first authorship. That even means that this paper can be easier found, when searching for her instead of my name. I just wanted to support a younger scientist.

And of course also a double first-authorship might be possible, especially representing  an adequate solution, in case another author even contributed more concerning the scientific content itself. In case of objections by the editors, the one, who contributed more, should to be the first author.

 

„B-word“?

 

But to come back to the amber paper of this article, it is surely not fair to reduce the scientist, who had the major scientific work on a paper secretly to a second author. It is highly unfair to leave him out in the international press release information. And I don’t trust to say here, what it is, when deleting his name entirely from a poster and an online abstract presentation and even impeding him to get a certification of a poster award in time for his work. Should one use the „b-word“? Generally bullying would be an act against the good scientific practice, but there would be clear proofs for malevolence against specifically somebody needed to get corresponding behaviors sanctioned. But when „only“ the elbow mentality is obvious, which means that people leave somebody out for their own better recognition, then the distinct malevolence against the victim is not clearly proven. Thus the interesting question arises: when is elbow behavior equal to bullying and when not?

 

Warning to young scientists

 

What I can say for sure is, even when the original bullying assumption is still a kind of questionable: after you complained, you might need to expect a real merciless and long lasting bullying. That’s why I intend to warn all young scientists: be careful and double check, with whom you cooperate. The wrong choice can be a failure as long as you do not agree being a bullying victim. The consequences can last over years and can destroy your whole career. I even once was told by a bullying victim that the accused institution did not even deny its bullying activities, but stated that depending of the kind of position, somebody has in an institute, an equality right would not be automatically existent. I go further and say: don’t become a natural scientist at all, except you are in a love relationship with an internationally highly influential professor.

In these days there are alternatives for possible natural scientists. Earlier I was a harsh critic of the modern gender sciences (sometimes also named genderism). But they have much financial capacities. Nobody there needs to sharpen his elbows, a good basis for fair careers, and based on that after a while surely also the most important basis for a good quality work!

 

Copyrights Stefan F. Wirth, Berlin 2019

 

Late winter insect life: winter aconite blossoms and dipteran visitors

When do the first insect activities in the new year occur? Can insects be active in winter, even in the presence of snow? The answer is generally yes, different insect species even use to appear on warmer winter days on top of snow layers. Examples are the limoniid crane fly Chionea belgica, a wingless dipteran, which can be observed on milder winter days on snow surfaces along forest edges in Central Europe. Also the fly Trichocera hiemalis belongs to the winter crane flies (Trichoceridae) and can be characterized by a very well developed cold resistance. It appears on sunny winter days between branches of leafless trees in swarms around invading sunlight beams.

 

The winter aconite as an early blooming flower and its biology

 

But what about insects, visiting blooming flowers? This requires the existance of early blossoms, which can grow and bloom under winter conditions. A well known example is the winter aconite Eranthis hyemalis, which outlasts the summer period only by its underground tubers. Their conspicuous yellow blossoms belong to the first blooming flowers in the year. In Central Europe, they begin to grow under suitable conditions in mid February. They require milder temperatures, but even persist in case an unusual cold snap would happen. The blossoms open only at sunshine and thus close shortly after sunset. Opening and closing is a growth process, which depends on temperature conditions. Such a phenomenon is called thermonasty.

 

The winter aconite as a neophyte in Germany

 

In Central Europe, such as in Germany, E. hyemalis is a neophyte. It is originally native to Southern European areas, Turkey, South-East-France, Italy, Bulgaria and Hungary.

The species was introduced to Central Europe (and North America) as ornamental plant for gardens. It is proven that it was in Germany already cultivated since the 16th century. The German botanist, nature researcher and medical doctor Joachim Camerarius reared the winter agonite, which he brought from Italy, since 1588 in his backyards.

 

Common pollinating insects

 

Pollinating insects of E. hyemalis are flies, bumblebees and bees. To reach the nectar inside the blossoms requires a proboscis length of about two mm, which is mostly given in bumblebees and bees.

 

Flowerbed in Berlin urban park Schillerpark

 

I documented via my videography (4K) and photography a smaller area of winter aconites in front of a wall at urban park „Schillerpark“ (honoring the German poet Friedrich Schiller) in Berlin. The bright bricks of that wall reflected efficiently the solar warmth and thus created suitable conditions for a late winter flowerbed full of life.

 

Video with winter aconite blossoms and pollunating flies, copyrights Stefan F. Wirth.

 

Most abundant insects in that winter aconite bed

 

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Western honey bee, copyrights Stefan F. Wirth

 

The western honey bee Apis mellifera was often seen on blossoms, but unfortunately was not captured via video footage. Our honey bee hibernates in a so called winter clusters with lower temperatures and low activities in workers. Beginning in late winter/ early spring, workers increase the nest temperature due to body movements up to 35°C. This is exactly the body temperature, workers need to fly out and collect first nectar and pollen, for example from the winter agonite.

 

https://www.instagram.com/p/Bt_oaLtF5NH/

Drone fly on blossom of the winter aconite, copyrights Stefan F. Wirth

 

The drone fly Eristalis tenax belongs to the hoverflies (Syrphidae). Their larvae develop in watery environments, where they use their conspicuous snorkel tube to breath air at the water surface. Adults are typical blossom visitors, preferring Asteraceae and Apiaceae. Interesting highlight of their biology is the migratory behavior. These migratory insects form swarms, which cross the Alpes towards Southern European areas by using suitable wind conditions, where they finally hibernate and reproduce. The next generation returns the same way back. Not all individuals participate these migratory flights and would try to hibernate in Central Europe. Hibernating individuals are always females, which were fertilized prior to their winter diapause or their migration and which lay their eggs in the subsequent spring or in southern regions during winter. In Germany they only survive in greater numbers in milder winters, which they persist in temperature-stable hideways, such as gaps inside walls or wooden habitats. These specimen can be usually observed early in the year, beginning with March, when visiting blooming flowers. Their numerous very early appearance in mid February 2019 might be due to a very warm summer 2018 and a subsequent very mild winter in north-eastern Germany (Berlin). I have no comparative findings regarding the usual blooming time of the winter aconite and the abundance of drone flies there for Berlin or even this specific urban park. I also don’t know about indications that due to a global warming, as in some migratory birds, less specimens of the fly would migrate and more stay to hibernate here around.

The research station „Randecker Maar“ in the Swabian Jura records changes in migratory flights of birds and insects. They discovered a distinct decline of numbers of migrating drone flies and interpret it as a result of the increasing application of poisonous substances in the agricultural sector. Whether they additionally consider this being due to more individuals hibernating, where they are, based on generally warmer temperatures (global warming) is unknown to me.

 

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Blow fly on blossom of the winter aconite, copyrights Stefan F. Wirth

 

The blow fly Calliphora vicina is a common blossom visitor in early spring and autumn. This fly, typically appearing in human settlements in Europe and the New World, is well adapted for an activity at lower temperatures (more than 13°C). While larvae develop in decomposing organic tissue (such as cadavers of animals), adults feed on nectar and pollen. They additionally incorprate saps from organic material with a strong odor.

C. vicina produces about five generation per year and throughout the year. The flies can even be active in winter, when temperatures reach a suitable level.

 

Other fly species were existant, but I did not determine them.

 

Time of footage and photo recording

 

Video footage and photos were recorded between 16 and 18 February 2019 in the urban park Schillerpark in Berlin.

 

Copyrights: Stefan F. Wirth, Berlin 2019.

Berlin Forest Grunewald and River Havel-Waterside

River Havel

 

The river Havel has its source in the Mecklenburg Lake Plateau and after 94 km flows in the area of the border between the federal states Brandenburg and Sachsen-Anhalt into the big river Elbe.

Havel runs besides the already mentioned states Brandenburg and Sachsen-Anhalt also through Berlin, the capital city of Germany. On its way, the river passes several bigger and smaller lakes, which serve as water reservoirs, even in hot summers, in which many german rivers and lakes from low water levels.

In its most parts, Havel is navigable, and weirs and locks regulate water levels and water supply.

Historically, Havel since at least 928 of our Western calculation played importent roles as natural border and water route. Through the middle ages up to times of the GDR wetlands as important ecosystems were stepwise drained. In more recent times the protection of unique nature refuges is proceeding. In 2004 for example, the Naturfreunde Deutschlands and the German Fishing Federation elected the Havel area as River Landscape of the year.

In 2005 the Federal Agency for Nature Conservation (BfN) and the Nature Biodiversity Conservation Union (NABU began the land restoration to create refuges for rare bird species , beaver, river lamprey, otters and other animals and plants.

The footage of my video was captured close to the bathing beach area „Lieper Bucht“. Visible are the Havel islands Lindwerder and Schwanenwerder as well as edges of the forest area „Düppeler Forst“.

River Havel and Forest Grunewald in Berlin, quadcopter footage. Copyrights Stefan F. Wirth, December 2018. Please like my video also on youtube, in case you like it.

 

Forest Grunewald

 

Adjacent to the Lieper-Bucht area, the huge urban forest Grunewald extends over 3000 hectare between the Berlin districts Charlottenburg and Zehlendorf.

It was elected as Forest Area of the Year by the Union of German Foresters in 2015. The Grunewald ecologically has a specific mosaic of ecosystems: heathlands, neglected grasslands, dunes, dandpits and marshlands. They all bear a remarkable biodiversity of rare animal and plant species.

Geomorphologically the Grunewald area was formed by galcio-fluvial processess during the Weichselian glaciation , which endet about 11600 years ago. Glacio-fluvial sands cobver the area in layers up to 20 meters and more.

The footage of my video also shows the so called Grunewald Tower. The memorial for the German Emperor  William I was planned in 1897 and finally built up by the architect Franz Schechten. The tower was finally inaugurated in 1899 and renovated between 2007 and 2011.

The footage was captured with a DJI Mavic pro quadcopter in mid December 2018.

 

 

Berlin, December 2018. Copyrights Stefan F. Wirth