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- updated 2014-06-13 -

Oriental Hornet
Vespa orientalis orientalis Linnaeus, 1771


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Die orientalische Hornisse Die orientalische Hornisse Die orientalische Hornisse
 Photos: Dieter Kosmeier, Zakynthos/Greek in '98

FERROELECTRIC-LIKE PROPERTIES OF HORNET STRUCTURES OR CONSTRACTION. J.S.
Ishay and L.Litinetsky. Department of Physiology and Pharmacology, Sackler, Faculty of Medicine, Tel - Aviv University, Ramat - Aviv,69978, Tel - Aviv, Israel.

...listen to the hornets here!

Various structures or constructions of the Oriental Hornet Vespa orientalis ( Hymenoptera, Vespinae) such as the cuticle, the spun silk and the comb cell walls discharge an electric current. In the dark, at a temperature range of 5 - 33° C, this current increases with rise in the temperature and decreases as the temperature drops. Between the ascending and descending "lines" of the current, a broad hysteresis is formed.þ The created current may attain a level of up to 700 nano Amperes (nA). Upon exposure to light of the hornets or its constructions, the electric current diminishes within minutes to its minimal values, no hysteresis is formed between the warming and cooling lines and the voltage increases. The event described suggest that the structures or constructures in question contain polar materials that undergo change in conformation and polarized, becoming a capacitor with layers of opposite polarization. This explains why the voltage rises and the current decreases during exposure to light, whereas in the dark (and at suitable temperature), the mentioned materials revert to a state of spontaneous polarization and gradually release, as electric current the charge that was picked up under illumination. The observed phenomena are characteristic of materials that are semiconductors endowed with ferroelectric properties. The influence of these properties on the gravity perception is discussed.

Vespa orientalis; Photo: Götz Lück in Turkey
Photo: Götz Lück, taken in Turkey


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orientalische Hornisse, Fotos: Kris Mercer, aufgenommen in 09/2002 in Mesa Chorio, Zypern orientalische Hornisse, Fotos: Kris Mercer, aufgenommen in 09/2002 in Mesa Chorio, Zypern
orientalische Hornisse, Fotos: Kris Mercer, aufgenommen in 09/2002 in Mesa Chorio, Zypern
 Photos: Kris Mercer, taken in 09/2002 in Mesa Chorio, Zypern

The first photo is a Oriental Hornet drinking milk, the second shows a hornet trying to take flight with a large piece of ham. A case of biting off more than you can fly with. The other is of hornets tucking into a raw hamburger.


Verbreitung von Vespa orientalis
 Distribution of Vespa orientalis


Fotos: Holger Martz, aufgenommen in 09/2001 in Tel Aviv im Stadtteil Raman Aviv, Israel Fotos: Holger Martz, aufgenommen in 09/2001 in Tel Aviv im Stadtteil Raman Aviv, Israel
Photos: Holger Martz, taken in 09/2001 in Tel Aviv / Raman Aviv; Israel


Ph
otos: Stephan Besche, taken in Turkey

THERMOELECTRIC EFFECT IN HORNET SILK AND THERMOREGULATION IN HORNET'S NEST
Jacob S. Ishay and Vered Barenholz Paniry, Department of Physiology and Pharmacology, Sackler Faculty of Medicine Tel Aviv University, Ramat Aviv 69978 Israel

The silk caps of the pupae of the Oriental hornet (Vespa orientalis, Vespinae, Hymenoptera) were measured for spontaneous electric current flow as a function of temperature. The measurements were made in the dark, within the range of biological temperatures. Clear correlation was detected between temperature rise and the increase in electric current forming in the silk. Thus at the temperature associated with maximal current, namely, 27-30°C, the electric current reached hundreds of nAmp whereas at 5°C the current was merely dozens of nAmp. Interestingly, the temperature range associated with optimal currents is also identical to the optimal temperature existant in the hornet nest and enabling proper development of the colony. In the Discussion section, an attempt is made to explain the thermoelectric mechanism in pupal silk and its contribution, as thermometer and thermostat, to thermoregulation of the individual pupae, each of which is an independent thermal unit. The thermoregulation here is compared with the mode of action of heat pipes in industry.


Oriental Hornet and Cataglyphis (Ants)

Vespa orientalis;  Foto: Oliver Schätzlein, aufgenommen in Kemer in der Türkei
 Photos: Oliver Schätzlein, taken in Turkey
Vespa orientalis;  Foto: Oliver Schätzlein, aufgenommen in Kemer in der Türkei

Vespa orientalis;  Foto: Oliver Schätzlein, aufgenommen in Kemer in der Türkei

Recent publications of Professor Jacob Ishay (E-Mail: physio7@post.tau.ac.il ):

  1. E. Rosenzweig, E. Horodiceanu, J.S. Ishay. Regeneration of guinea pig facial nerve: The effect of hypergravity. 17 (6/7): 129-137, 1996.

  2. J.S. Ishay, M. Shmuelson. Thermoelectric properties of the hornet comb: A device for producing transforming and storing electrical energy for the entire colony. Physiol. Chem. & Physics and Medical NMR. 28: 41-54, 1996.

  3. J.S. Ishay, A. Landsberg, S. Pelah. Micromorphology of the fibers behind the frons plate and its adjacent regions in the Oriental hornet (Hymenoptera, Vespinae). Scanning Microscopy 10(1): 187-208, 1996.

  4. J.S. Ishay, L. Litinetsky. Thermoelectric current in hornet cuticle: Morphological and electrical changes induced by temperature and light. Physiol. Chem. & Physics and Medical NMR 28: 55-67, 1996.

  5. O. Goldstein, L. Litinetsky, J.S. Ishay. Extraretinal photoreception in hornets. Phys. Chem. & Physics and Medical NMR. 28: 129-136, 1996.

  6. O. Goldstein, J.S. Ishay. Morphology of a Putative New Peripheral Photoreceptor in Social Wasps. Physiol. Chem. Phys. & Medical NMR. 28(4): 255-266, 1996.

  7. J.S. Ishay, O. Goldstein, E. Rosenzweig, D. Kalicharan, W.L. Jongebloed. Hornet yellow cuticle Microstructure: A photovoltaic system. Phys. Chem. Phys. & Medical NMR, 29:71-93, 1997.

  8. J.S. Ishay, V. Barenholz-Paniry, A. Bitler. On hornet silk as a photodetector: considerations of current, voltage and resistance. Phys. Chem. & Phys. and Medical NMR, 29:95-108, 1997.

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