@article{SchmuckKobeltLinsenmair1988, author = {Schmuck, R. and Kobelt, F. and Linsenmair, Karl Eduard}, title = {Adaptations of the reed frog Hyperbolius viridiflavus (Anura, Hyperbolidae) to its arid environment: V. Iridophores and nitrogen metabolism}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78094}, year = {1988}, abstract = {Ofall amphibians living in arid habitats, reed frogs (belonging to the super species Hyperolius viridiflavus) are the most peculiar. Froglets are able to tolerate dry periods of up to 35 days or longer immediately after metamorphosis, in climatically exposed positions. They face similar problems to estivating juveniles, i.e. enduranee of long periods of high temperature and low RH with rather limited energy and water reserves. In addition, they must have had to develop meehanisms to prevent poisoning by nitrogenous wastes that rapidly accumulate during dry periods as a metabolie consequenee of maintaining a non-torpid state. During dry periods, plasma osmolarity of H. v. taeniatus froglets strongly increased, mainly through urea accumulation. Urea accumulation was also observed during metamorphic climax. During postmetamorphic growth, chromatophores develop with the density and morphology typical of the adult pigmentary pattern. The dermal iridophore layer, which is still incomplete at this time, is fully developed within 4-8 days after metamorphosis, irrespective of maintenance conditions. These iridophores mainly contain the purines guanine and hypoxanthine. The ability of these purines to reflect light provides an excellent basis for the role of iridophores in temperature regulation. In individuals experiencing dehydration stress, the initial rate of purine synthesis is doubled in eomparison to specimens continuously maintained under wet season conditions. This increase in synthesis rate leads to a rapid increase in the thiekness of the iridophore layer, thereby effectively reducing radiation absorption. Thus, the danger of overheating is diminished during periods of water shortage when evaporative cooling must be avoided. After the development of an iridophore layer of sufficient thickness for effective radiation reflectance, synthesis of iridophore pigments does not cease. Rather, this pathway is further used during the remaining dry season for solving osmotic problems eaused by accumulation of nitrogenous wastes. During prolonged water deprivation, in spite of reduced metabolic rates, purine pigments are produced at the same rate as in wet season conditions. This leads to a higher relative proportion of nitrogen end products being stored in skin pigments under dry season conditions. At the end of an experimental dry season lasting 35 days, up to 38\% of the accrued nitrogen is stored in the form of osmotically inactive purines in thc skin. Thus the osmotic problems caused by evaporative water loss and urea production are greatly reduced.}, subject = {Biologie}, language = {en} } @article{LinsenmairSchmuck1988, author = {Linsenmair, Karl Eduard and Schmuck, R.}, title = {Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. III. Aspects of nitrogen metabolism and osmuregulation in the reed frog, H. viridiflavus taeniatus, with special reference to the role of iridophores}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78108}, year = {1988}, abstract = {Reed frogs of the superspecies Hyperolius viridiflavus occur throughout the seasonally very dry and hot African savannas. Despite their small size (300-700 mg), estivating reed frogs do not avoid stressful conditions above ground by burrowing into the soil, but endure the inhospitable climate relatively unprotected, clinging to mostly dry grass sterns. They must have emcient mechanisms to enable them to survive e.g. very high temperatures, low relative hurnidities, and high solar radiation loads. Mechanisms must also have developed to prevent poisoning by the nitrogenous wastes that inevitably result from protein and nucleotide turnover. In contrast to fossorial amphibians, estivating reed frogs do not become torpid. Reduction in metabolism is therefore rather Iimited so that nitrogenous wastes accumulate faster in these frogs than in fossorial amphibians. This severely aggravates the osmotic problems caused by dehydration. During dry periods total plasma osmolarity greatly increases, mainly due to urea accumulation. Of the total urea accumulated over 42 days of experimental water deprivation, 30\% was produced during the first 7 days. In the next 7 days rise in plasma urea content was negligible. This strong initial increase of urea is seen as a byproduct of elevated amino acid catabolism following the onset of dry conditions. Tbe rise in total plasma osmolarity due to urea accumulation, however, is not totally disadvantageous, but enables fast rehydration when water is available for very short periods only. Voiding of urine and feces eeases once evaporative water loss exceeds 10\% of body weight. Tberefore, during continuous water deprivation, nitrogenous end products are not excreted. After 42 days of water deprivation, bladder fluid was substantially depleted, and urea coneentration in the remaining urine (up to 447 mM) was never greater than in plasma fluid. Feces voided at the end of the dry period after water uptake contained only small amounts of nitrogenous end products. DSF (dry season frogs) seemed not to be uricotelic. Instead, up to 35\% of the total nitrogenous wastes produced over 42 days of water deprivation were deposited in an osmotically inert and nontoxic form in iridophore crystals. The increase in skin purine content averaged 150 µg/mg dry weight. If urea had been the only nitrogenous waste product during an estivation period of 42 days, lethal limits of total osmolarity (about 700 mOsm) would have been reached 10-14 days earlier. Thus iridophores are not only involved in colour change and in reducing heat load by radiation remission, but are also important in osmoregulation during dry periods. The seIective advantages of deposition of guanine rather than uric acid are discussed.}, subject = {Biologie}, language = {en} } @article{GeiseLinsenmair1988, author = {Geise, W. and Linsenmair, Karl Eduard}, title = {Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. IV. Ecological significance of water economy with comments on thermoregulation and energy allocation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30570}, year = {1988}, abstract = {No abstract available}, language = {en} } @article{Linsenmair1986, author = {Linsenmair, Karl Eduard}, title = {Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment: II. Some aspects of the water economy of H. viridiflavus nitidulus under wet and dry ...}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78395}, year = {1986}, abstract = {Adaptations to aridity ofthe reedfrog Hyperolius viridiflavus nitidulus, living in different parts of the seasonally very dry and hot West African savanna, are investigated ...}, subject = {Zoologie}, language = {en} } @article{KobeltLinsenmair1992, author = {Kobelt, F. and Linsenmair, Karl Eduard}, title = {Adaptations of the reed frog Hyperolius viridiflavus (Hyperoliidae) to its arid environment. VI. The iridophores in the skin as radiation reflectors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30563}, year = {1992}, abstract = {No abstract available}, language = {en} } @article{KobeltLinsenmair1986, author = {Kobelt, Frank and Linsenmair, Karl Eduard}, title = {Adaptations of the reed frog Hyperolius viridiflavus to its arid environment. I. The skin of Hyperolius viridiflavus nitidulus in wet and dry season conditions.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30551}, year = {1986}, abstract = {Hyperolius viridiflavus nitidulus inhabits parts of the seasonally very hot and dry West African savanna. During the long lasting dry season, the small frog is sitting unhidden on mostly dry plants and has to deal with high solar radiation load (SRL), evaporative water loss (EWL) and small energy reserves. It seems to be very badly equipped to survive such harsh climatic conditions (unfavorable surface to volume ratio, very limited capacity to st{\"o}re energy and water). Therefore, it must have developed extraordinary efficient mechanisms to solve the mentioned Problems. Some of these mechanisms are to be looked for within the skin of the animal (e.g. protection against fast desiccation, deleterious effects of UV radiation and over-heating). The morphology of the wet season skin is, in most aspects, that of a "normal" anuran skin. It differs in the Organization of the processes of the melanophores and in the arrangement of the chromatophores in the Stratum spongiosum, forming no "Dermal Chromatophore Unit". During the adaptation to dry season conditions the number of iridophores in dorsal and ventral skin is increased 4-6 times compared to wet season skin. This increase is accompanied by a very conspicuous change of the wet season color pattern. Now, at air temperatures below 35° C the color becomes brownish white or grey and changes to a brilliant white at air temperatures near and over 40° C. Thus, in dry season State the frog retains its ability for rapid color change. In wet season State the platelets of the iridophores are irregularly distributed. In dry season State many platelets become arranged almost parallel to the surface. These purine crystals probably act as quarter-wave-length interference reflectors, reducing SRL by reflecting a considerable amount of the radiated energy input. EWL is as low as that of much larger xeric reptilians. The impermeability of the skin seems to be the result of several mechanisms (ground substance, iridophores, lipids, mucus) supplementing each other. The light red skin at the pelvic region and inner sides of the limbs is specialized for rapid uptake of water allowing the frog to replenish the unavoidable EWL by using single drops of dew or rain, available for only very short periods.}, language = {en} } @article{Linsenmair1991, author = {Linsenmair, Karl Eduard}, title = {Allokation elterlicher Investition beim Bienenwolf Philantus triangulum (Hymenoptera: Sphecidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78191}, year = {1991}, abstract = {No abstract available}, subject = {Zoologie}, language = {de} } @article{Linsenmair1972, author = {Linsenmair, Karl Eduard}, title = {Anemomenotactic orientation in beetles and scorpions}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78118}, year = {1972}, abstract = {Scorpions, living in North African semideserts are - in spite of disrupting experimental interferences - able to maintain a certain direction in their natural environment in the dark on a plane surface. Under comparable laboratory conditions, excluding the possibility of light or gravity orientation, they can orient themselves if a directed air current passes over the "arena." In most cases the scorpions do not run necessarily with or against the wind, but rather maintain constant angles to the air current for anywhere from minutes to many hours. They are running anemomenotactically (ref. 1). Under identical conditions many species of beetles also orient themselves to air currents (refs. 2 to 4). The main problems to be solved in the study of anemomenotactic orientation are: (1) Which physical qualities of the air current have an influence on the anemomenotaxis? (2) With which sense organs do beetles and scorpions perceive wind directions? (3) Which physiological mechanism is the basis of anemomenotactic orientation? (4) What is the biological significance of anemomenotaxis in beetles and scorpions? With respect to these problems, more study has been done on beetles than on scorpions. Therefore, due to lack of space, I shall discuss mainly some of the results obtained in experiments with dung beetles (Geotrupes silvaticus, G. ,Stercorarius, G. armifrons, G. niger, Scarabaeus variolosus) and tenebrionid beetles (Tenebrio molitor, Pimelia grossa, P. tenuicomis, Scaurus dubius).}, subject = {Biologie}, language = {en} } @article{Linsenmair1968, author = {Linsenmair, Karl Eduard}, title = {Anemomenotaktische Orientierung bei Skorpionen (Chelicerata, Scorpiones)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44589}, year = {1968}, abstract = {1. Scorpions can orient menotactically to horizontal air currents (Fig. 1). 2. Changing the wind velocity from 0,05-0,1 m/sec to 3--5 m/sec has no influence on the menotactic angle kept by an anemomenotactic oriented scorpion (Fig. 2). 3. The receptors percieving the direction of air currents are the trichobothria. 4. Orientation to horizon landmarks, anemomenotactic and astromenotactic orientation does not exclude each other but complete themthelves mutually: a) A scorpion orienting to horizon landmarks learns the corresponding anemomenotactic and astromenotactic angle (Fig. 4). b) While orienting anemomenotactically (which is normally the main means of orientation when landmarks are absent) they continously learn new astromenotactical angles (Fig. 5), thus compensating for the movement of the moon or sun which can not be compensated otherwise. c) Short calms and short changes of wind direction can be overcome by astrotaxis.}, language = {de} } @article{Linsenmair1969, author = {Linsenmair, Karl Eduard}, title = {Anemomenotaktische Orientierung bei Tenebrioniden und Mistk{\"a}fern (Insecta, Coleoptera)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44512}, year = {1969}, abstract = {1. Die Feistk{\"a}fer Pimelia grossa, P. tenuicornis, der Mehlk{\"a}fer Tenebrio molitor, die Mistk{\"a}fer Geotrupes silvaticus und G. stercorarius konnen sich unter entsprechenden Bedingungen rein anemomenotaktisch orientieren (Abb. 1-8). Sie bevorzugen Laufwinkel, die in relativ enge Winkelbereiche rechts und links der beiden Grundrichtungen f{\"u}hren (Abb. 3, 4, 26). 2. Die Bevorzugung bestimmter Winkelgr{\"o}ßen andert sich bei Geotrupes nicht gesetzmig mit der Tageszeit, der Temperatur (im Bereich 18-28° C) oder dem F{\"u}tterungszustand (Abb. 8-11). 3. Die untere Grenze der Windst{\"a}rke, die eine menotaktische Einstellung erm{\"o}glicht, liegt f{\"u}r die Mistk{\"a}fer bei etwa 0,15 m/sec, f{\"u}r die Feistk{\"a}fer bei etwa 0,4 m/sec. Die obere Grenze befindet sich bei Geschwindigkeiten, die den K{\"a}fern ein Vorw{\"a}rtskommen unm{\"o}glich machen. 4. Bei der menotaktischen Einstellung wird nur die Reizrichtung nicht aber die Reizstarke bewertet (Abb. 13-15). 5. Die Kontinuitat des Luftstroms ist keine Voraussetzung f{\"u}r die anemomenotaktische Orientierung: Die K{\"a}fer orientieren sich auch nach kurzen Windst{\"o}ßen (Abb. 17, 19, 21). W{\"a}hrend der Windstille kommt es zu regelhaften Abweichungen von dem bei Wind eingehaltenen Kurs (Abb. 18). Das Ausmaß dieser Abweichungen wird nach h{\"a}ufigen Windunterbrechungen stark verringert (Abb. 20). 6. Gegen Turbulenzen des Luftstroms, wie sie {\"u}ber unebenem Untergrund entstehen, ist die Anemomenotaxis der K{\"a}fer nicht sehr anf{\"a}llig (Abb. 22). 7. Die Sinnesorgane, die dem intakten K{\"a}fer die Windrichtungsbestimmung erm{\"o}glichen, sprechen auf Bewegungen im Pedicellus-Flagellumgelenk an. Ein Verlust der Endkolben hat beim Mistk{\"a}fer keinen Einfluß auf die Richtungs- und Winkelgr{\"o}ßenwahl, auch die Streuung wird nicht signifikant gr{\"o}ßer. 2 Flagellenglieder pro Antenne erm{\"o}glichen bei Windgeschwindigkeiten um oder {\"u}ber 1 m/sec noch eine anemomenotaktische Orientierung (Tabelle 3). 8. Bei 3 Mistk{\"a}fern, deren F{\"u}hler 4 Wochen bzw. 4 Monate vor dem Versuch entfernt worden waren, konnte wieder eine Orientierung nach der Windrichtung nachgewiesen werden (Abb. 23, Tabelle 1). 9. Die Kafer konnen Laufwinkel intramodal vierdeutig transponieren (z.B. Abb. 28, 29). Am deutlichsten tritt diese F{\"a}higkeit bei Versuchsneulingen zutage, deren Laufe rein fluchtmotiviert sind: Sie w{\"a}hlen normalerweise denjenigen der 4 m{\"o}glichen Laufwinkel, der der Aufsetzrichtung am n{\"a}chsten liegt (vgl. Abb. 25, 26). 10. Die Existenz und die Wirkungsrichtung eines Drehkommandos, sowie die Beteiligung beider Grundorientierungen an der Anemomenotaxis werden nachgewiesen (Abb. 31). Die F{\"a}higkeit, eine gleichbleibende Drehkommandogr{\"o}ße (die nie zu einer st{\"a}rkeren Abweichung als 90° von einer Grundrichtung f{\"u}hren kann) mit verschiedenem Vorzeichen der Drehrichtung versehen zu konnen und die M{\"o}glichkeit zur Taxisumkehr (Abb. 32) erkl{\"a}ren die orientierungsphysiologische Seite des vierdeutigen intramodalen Transponierens. 11. Versuchsergebnisse, die Aussagen uber den physiologischen Mechanismus der Anemomenotaxis der K{\"a}fer zulassen, sprechen f{\"u}r einen Kompensationsmechanismus. Die gegen die Kompensationstheorie der Menotaxis (JANDER, 1957) vorgebrachten Argumente werden im Rahmen der bisherigen Resultate kurz diskutiert. 12. Die m{\"o}glichen biologischen Bedeutungen der Anemomenotaxis werden besprochen. Es wird angenommen, daß sie beim Appetenzverhalten des nach geruchlichen Schl{\"u}sselreizen "suchenden" K{\"a}fers ihre biologisch wichtigste Aufgabe erf{\"u}llt. Sie kann auch die basalen Aufgaben einer Raumorientierung {\"u}bernehmen und so z.B. kompaßtreue Fluchtkurse steuern.}, language = {de} } @article{Linsenmair1994, author = {Linsenmair, Karl Eduard}, title = {Biologische Vielfalt und {\"o}kologische Stabilit{\"a}t}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31157}, year = {1994}, abstract = {No abstract available}, language = {en} } @article{MaschwitzFialaLinsenmair1994, author = {Maschwitz, Ulrich and Fiala, Brigitte and Linsenmair, Karl Eduard}, title = {Clerodendrum fistulosum (Verbenanceae), an unspecific myrmecophyte from Borneo with spontaneously opening domatia}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31013}, year = {1994}, abstract = {Clerodendrumjistulosum Becc. is a true myrmecophyte as it offers nesting space for ants in hollow intemodes. In contrast to previous reports our investigations proved that these domatia open by themselves, thus providing cavities for a variety of different ant species. In Sarawak, Malaysia, we did not find an obligate relationship between C. jistulosum and a specific ant-partner. For comparison, studies on herbarium material of other Clerodendrum species were carried out a further species, C. deflexum from the Malay Peninsula and Sumatra presumably also is myrmecophytic.}, language = {en} } @article{Linsenmair1984, author = {Linsenmair, Karl Eduard}, title = {Comparative studies on the social behaviour of the desert isopod Hemilepistus reaumuri and of a Porcellio species}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30846}, year = {1984}, abstract = {Behavioural adaptations have made the desert isopod Hemilepistus reaumuri the most successful herbivore and detritivore of the macrofauna of many arid areas in North Africa and Asia Minor. For survival and reproduction Hemilepistus is dependent on burrows. New burrows can only be dug during spring. With the time-consuming digging of a burrow, Hemilepistus has only made the first step towards solving its ecological problems. The burrows are vital and have to be continuously defended against competitors. This requirement is met by co-operation of individuals within the framework of a highly developed social behaviour. In spring adults form monogamous pairs in which partners recognize each other individually and later form, with their progeny, strictly closed family communities. Hemilepistus is compared with a Porcellio' sp. which has developed, convergently, a social behaviour which resembles that of Hemilepistus in many respects, but differs essentially in some aspects, partly reflecting differences in ecological requirements. This and a few other Porcellio species demonstrate some possible steps in the evolution of the social behaviour of Hemilepistus. The female Hemilepistus is-in contrast to Porcellio sp. - semelparous and the selective advantages of monogamy in its environment are not difficult to recognize. This chapter discusses how this mating system could have evolved and especially why monogamous behaviour is also the best method for the Hemilepistus male to maximize its reproductive success. The cohesion of pairs and of family communities in Hemilepistus is based on a highly developed chemical communication system. Individual- and family-specific badges owe their specificity to genetically determined discriminating substances. The nature of the badges raises a series of questions: e.g. since alien badges release aggression, how do parents avoid cannibalizing their young? Similar problems arise from the fact that family badges are mixtures of chemical compounds of very low volatility with the consequence that they can only be transferred by direct contact and that during moulting all substances are lost which an individual does not produce itself. It is shown that in solving these problems inhibiting properties (presumably substances) and learning play a dominant role.}, language = {en} } @article{LinsenmairJander1963, author = {Linsenmair, Karl Eduard and Jander, R.}, title = {Das "Entspannungsschwimmen" von Velia und Stenus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44663}, year = {1963}, abstract = {No abstract available}, language = {de} } @article{Linsenmair1972, author = {Linsenmair, Karl Eduard}, title = {Die Bedeutung familienspezifischer "Abzeichen" f{\"u}r den Familienzusammenhalt bei der sozialen W{\"u}stenassel Hemilepistus reaumuri Audouin und Savigny}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32663}, year = {1972}, abstract = {No abstract available}, language = {de} } @article{Linsenmair1970, author = {Linsenmair, Karl Eduard}, title = {Die Interaktion der paarigen antennalen Sinnesorgane bei der Windorientierung laufender Mist- und Schwarzk{\"a}fer (Insecta, Coleoptera)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44507}, year = {1970}, abstract = {1. Bei der Anemomenotaxis arbeiten die Windrichtungen perzipierenden, paarigen Sinnesorgane der Antennen - vermutlich die Johnstonschen Organe - als Synergisten zusammen. Der Ausfall der f{\"u}r die Windrichtung spezifischen afferenten Meldungen eines F{\"u}hlers f{\"u}hrt zu einer Halbierung der Drehtendenzst{\"a}rke (Abb.I-ll). Es konnten keine Anhaltspunkte gefunden werden, die auf eine direkte zentrale Kompensation dieses Effektes hinweisen. Verschiedene Arten der Ausschaltung, totalc (Abb.2) oder teilweise (Abb. 4) Amputation (bei der der Pedicellus unverletzt bleibt) oder Blockierung des Pedicellus-Flagellumgelenks durch Lackierung (Abb.3), bewirken dieselben {\"A}nderungen im Orientierungsverhalten. 2. Der einzelne F{\"u}hler fungiert bei der Anemomenotaxis als "zweisinniger Lenker". Ein K{\"a}fer mit nur einem F{\"u}hler ist - nach einer gen{\"u}gend langen Erholungszeit - noch f{\"a}hig, die Windrichtung festzustellen und zu ihr eindeutige menotaktische Kurse zu steuern (vgl. z. B. Abb. 1, 9). Außerdem kann er sich wie ein intakter K{\"a}fer (Abb. 14) bei pl{\"o}tzlicher Anderung der Reizrichtung um den kleineren Winkelbetrag zu seiner Sollrichtung zur{\"u}ckdrehen (Abb. 15). 3. Zwischen Drehtendenzst{\"a}rke und Reizrichtung besteht nach den Ergebnissen der Ausschaltversuche eine Sinusfunktion. Gleichgroße Rechts- oder Linksabweichungen des K{\"a}fers von der positiven oder negativen Grundrichtung werden von rechtem und linkem F{\"u}hler mit der gleichen Drehtendenzst{\"a}rke bewertet (Abb. 13). Es ist deshalb naheliegend, anzunehmen, daß jeder F{\"u}hler bei der Reizrichtungsbewertung seinen Abweichungsbetrag von der n{\"a}chsten der beiden Grundstellungen mißt. In einer Grundstellung befindet sich der F{\"u}hler jeweils dann, wenn sich der K{\"a}fer genau gegen oder mit dem Wind eingestellt hat. 4. Afferente Drehtendenz und efferentes Drehkommando sind Dreherregungsgr{\"o}ßen, die sich bei Einstellung des Sollwinkels durch ihre antagonistische Wirkung aufheben. Halbierung der Drehtendenzst{\"a}rke durch Ausschaltung eines F{\"u}hlers f{\"u}hrt demnach erwartungsgem{\"a}ß zu einer Verdopplung der Drehkommandowirkung. Daraus und aus der Sinusf{\"o}rmigkeit der Drehtendenzst{\"a}rkenkurve ergibt sich, daß Drehkommandogr{\"o}ßen, die beim intakten K{\"a}fer die Einhaltung von Menotaxiswinkeln von > 30° zur Folge haben, von der halbierten Drehtendenz nicht mehr kompensiert werden k{\"o}nnen. Die K{\"a}fer k{\"o}nnen dann Dauerrotationen vermeiden, indem sie das Drehkommando soweit abschw{\"a}chen, daß es von der halbierten Drehtendenz wieder kompensiert wird (Abb. 8). 5. Standardabweichung und mittlere Laufwinkelgr{\"o}ße sind miteinander korreliert. Die Korrelation gilt in gleicher Weise f{\"u}r das intakte und das einseitig antennenamputierte Versuchstier. 6. Nach einer einseitigen F{\"u}hlerausschaltung bevorzugen Tenebrio molitor und Scaurus dubius anf{\"a}nglich Laufrichtungen zur Seite der intakten Antenne hin. Bei allen VT-Arten nimmt die Neigung zum intramodalen Winkeltransponieren nach F{\"u}hlerausschaltung sehr stark zu (Abb. 12). 7. Den Grundorientierungen - positive und negative Anemotaxis - liegt, wie auch der Menotaxis, kein tropotaktischer Mechanismus der F{\"u}hlerverschaltung zugrunde. Anemotaxis und Anemomenotaxis unterscheiden sich lediglich dadurch, daß bei letzterer ein efferentes Drehkommando die Sollrichtung verstellt. 8. Die experimentellen Befunde werden im Hinblick auf den, der Anemomenotaxis zugrunde liegenden, physiologischen Mechanismus diskutiert: Sie lassen sich alle widerspruchslos mit einem Kompensationsmechanismus vereinen.}, language = {de} } @article{Linsenmair1973, author = {Linsenmair, Karl Eduard}, title = {Die W{\"u}stenassel: Sozialverhalten und Lebensraum.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44493}, year = {1973}, abstract = {Unter den Krebsen ist als gr{\"o}ßerer Gruppe allein den Landasseln (Oniscoidea) eine Eroberung des Festlandes gelungen. Ihre Anpassung an das Landleben blieb aber bislang recht mangelhaft, z. B. fehlt ein wirksamer Verdunstungsschutz. Wie zu erwarten, bewohnen daher die meisten Landasselarten feuchte Lebensst{\"a}tten. Zu den wenigen Ausnahmen z{\"a}hlt die W{\"u}stenassel Hemilepistus reaumuri, die nordafrikanische und kleinasiatische Halbw{\"u}sten - stellenweise auch echte W{\"u}stengebiete - besiedelt. Es sind vor allem Verhaltensanpassungen, die den W{\"u}stenasseln in diesen w{\"a}hrend vieler Monate trockenheißen Extrembiotopen nicht nur ein Oberleben erlauben, sondern sie dar{\"u}ber hinaus noch vielerorts zum erfolgreichsten Faunenelement machen.}, language = {de} } @article{FlorenLinsenmairMueller2022, author = {Floren, Andreas and Linsenmair, Karl Eduard and M{\"u}ller, Tobias}, title = {Diversity and functional relevance of canopy arthropods in Central Europe}, series = {Diversity}, volume = {14}, journal = {Diversity}, number = {8}, issn = {1424-2818}, doi = {10.3390/d14080660}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285924}, year = {2022}, abstract = {Although much is known about the ecology and functional importance of canopy arthropods in temperate forests, few studies have tried to assess the overall diversity and investigate the composition and dynamics of tree-specific communities. This has impeded a deeper understanding of the functioning of forests, and of how to maintain system services. Here, we present the first comprehensive data of whole arthropod communities, collected by insecticidal knockdown (fogging) from 1159 trees in 18 study areas in Central Europe during the last 25 years. The data includes 3,253,591 arthropods from 32 taxa (order, suborder, family) collected on 24 tree species from 18 genera. Fogging collects free-living, ectophytic arthropods in approximately the same number as they occur in the trees. To our knowledge, these are the most comprehensive data available today on the taxonomic composition of arboreal fauna. Assigning all arthropods to their feeding guild provided a proxy of their functional importance. The data showed that the canopy communities were regularly structured, with a clear dominance hierarchy comprised of eight 'major taxa' that represented 87\% of all arthropods. Despite significant differences in the proportions of taxa on deciduous and coniferous trees, the composition of the guilds was very similar. The individual tree genera, on the other hand, showed significant differences in guild composition, especially when different study areas and years were compared, whereas tree-specific traits, such as tree height, girth in breast height or leaf cover, explained little of the overall variance. On the ordinal level, guild composition also differed significantly between managed and primary forests, with a simultaneous low within-group variability, indicating that management is a key factor determining the distribution of biodiversity and guild composition.}, language = {en} } @article{FlorenKruegerMuelleretal.2015, author = {Floren, Andreas and Kr{\"u}ger, Dirk and M{\"u}ller, Tobias and Dittrich, Marcus and Rudloff, Renate and Hoppe, Bj{\"o}rn and Linsenmair, Karl Eduard}, title = {Diversity and interactions of wood-inhabiting fungi and beetles after deadwood enrichment}, series = {PLoS ONE}, volume = {10}, journal = {PLoS ONE}, number = {11}, doi = {10.1371/journal.pone.0143566}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-145129}, pages = {e0143566}, year = {2015}, abstract = {Freshly cut beech deadwood was enriched in the canopy and on the ground in three cultural landscapes in Germany (Swabian Alb, Hainich-Dun, Schorfheide-Chorin) in order to analyse the diversity, distribution and interaction of wood-inhabiting fungi and beetles. After two years of wood decay 83 MOTUs (Molecular Operational Taxonomic Units) from 28 wood samples were identified. Flight Interception Traps (FITs) installed adjacent to the deadwood enrichments captured 29.465 beetles which were sorted to 566 species. Geographical 'region' was the main factor determining both beetle and fungal assemblages. The proportions of species occurring in all regions were low. Statistic models suggest that assemblages of both taxa differed between stratum and management praxis but their strength varied among regions. Fungal assemblages in Hainich-Dun, for which the data was most comprehensive, discriminated unmanaged from extensively managed and age-class forests (even-aged timber management) while canopy communities differed not from those near the ground. In contrast, the beetle assemblages at the same sites showed the opposite pattern. We pursued an approach in the search for fungus-beetle associations by computing cross correlations and visualize significant links in a network graph. These correlations can be used to formulate hypotheses on mutualistic relationships for example in respect to beetles acting as vectors of fungal spores.}, language = {en} } @article{FialaGrunskyMaschwitzetal.1994, author = {Fiala, Brigitte and Grunsky, Harald and Maschwitz, Ulrich and Linsenmair, Karl Eduard}, title = {Diversity of ant-plant interactions: Protective efficacy in Macaranga species with different degrees of ant-association.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32905}, year = {1994}, abstract = {The pioneer tree Macaranga in SE Asia has developed manyfold associations with ants. The genus comprises all stages of interaction with ants, from facultative relationships to obligate myrmecophytes. Only myrmecophytic Macaranga offer nesting space for ants and are associated with a specific ant partner. The nonmyrmecophytic species are visited by a variety of different ant species which are attracted by extrafloral nectaries (EFN) and food bodies. Transitional Macaranga species like M. hosei are colonized later in their development due to their stem structure. Before the colonization by their specific Crematogaster partner the young plants are visited by different ant species attracted by EFN. These nectaries are reduced and food body production starts as soon as colonization becomes possible. We demonstrated earlier that obligate ant partners can protect their Macaranga plants against herbivore damage and vine cover. In this study we focused on nonspecific interactions and studied M. tanarius and M. hosei, representing a non-myrmecophyte and a transitional species respectively. In ant exclusion experiments both M. tanarius and M. hosei suffered significantly higher mean leaf damage than controls, 37\% versus 6\% in M. hosei, 16\% versus 7\% in M. tanarius. M. tanarius offers both EFN and food bodies so that tests for different effects of these two food rewards could be conducted. Plants with food bodies removed but with EFN remaining had the lowest mean increase of herbivore damage of all experimental groups. Main herbivores on M. hosei were mites and caterpillars. Many M. tanarius plants were infested by a shootborer. Both Macaranga species were visited by various ant species. Crematogaster spp. being the most abundant. We found no evidence for any specific relationships. The results of this study strongly support the hypothesis that non-specific, facultative associations with ants can be advantageous for Macaranga plants. Food bodies appear to have lower attractive value for opportunistic ants than EFN and may require a specific dietary adaptation. This is also indicated by the fact that food body production in the transitional M. hosei does not start before stem structure allows a colonization by the obligate Crematogaster species. M. hosei thus benefits from facultative association with a variety of ants until it produces its first domatia and can be colonized by its obligate mutualist.}, language = {en} }