Journal of comparative physiology

, Volume 132, Issue 1, pp 55–68 | Cite as

Mechanoreceptive bristles on the head of the blowfly: Mechanics and electrophysiology of the macrochaetae

  • Joachim Theiß


On the heads of the femaleCalliphora studied, in the region between the two compound eyes and at the dorsal back margin, there are about 80 macrochaetae and about 500 smaller mechanoreceptive hairs. Their topography is described, with data on size, angle of inclination and direction of curvature (Figs. 1, 2, 3). When a frontal macrochaeta is rotated about its base in different directions, restoring force is maximal with displacement in the direction of curvature; for the bristles on the back of the head, the force is maximal in the opposite direction. As either type of hair is displaced to progressively greater angles in the direction of greatest restoring force, the bristle joint behaves like a nonlinear spring until the shaft meets the edge of the socket (e.g., 8–10° for the ocellar bristles; Fig. 4). When released the shaft returns to the resting position with a non-oscillatory, strongly damped movement.

Each of the bristles and hairs is innervated by one bipolar sensory cell. Nerve impulses are recorded from this cell only when the hair is displaced into the semicircular sector associated with the greatest restoring forces. The threshold angle is about 1°. The angles to which the bristles are moved by air flow (up to 4.5 m/s), airborne sound (50–1000 Hz, 90 dB) and cuticle-conducted vibration (oscillation amplitude in the frequency range of the wingbeat ca. 100 μm) do not exceed this threshold. Stepwise displacement in the direction of curvature elicits phasic excitation that decays approximately exponentially. In the ocellar bristles, for example, the latency to appearance of the first nerve impulse amounts to about 2 ms and the time constant of frequency decay is about 30 ms. With ramp stimuli peak impulse frequency rises in proportion to the logarithm of the rate of displacement, within the range 10–500°/s (Fig. 7). The peak frequency is independent of final angle. The sensitivity of the receptor to movement of the hair shaft within the sector from resting position to socket edge shows a distinct maximum at 1–3° past the threshold angle (Figs. 11, 12). With imposed sinusoidal oscillation the frequency characteristics are approximately linear up to a stimulus frequency of 160 Hz (Fig. 9). But there is considerable adaptation, dependent on stimulus frequency. The macrochaetae are probably pure event detectors, signalling the moment and site at which any suprathreshold contact is made between the body surface and its surroundings. Stimulus-excitation transformation by the ocellar bristles is discussed.


Stimulus Frequency Nerve Impulse Nonlinear Spring Hair Shaft Sinusoidal Oscillation 


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  1. Bischof, H.-J.: Die keulenförmigen Sensillen auf den Cerci der GrilleGryllus bimaculatus als Schwererezeptoren. J. Comp. Physol.98, 277–288 (1975)Google Scholar
  2. Burkhardt, D.: Allgemeine Sinnesphysiologie und Elektrophysiologie der Receptoren. Fortschr. Zool.13, 146–189 (1961)Google Scholar
  3. Digby, P.S.B.: Flight activity in the blowfly,Calliphora erythrocephala in relation to wind speed, with special reference to adaptation. J. Exp. Biol.35, 776–795 (1958)Google Scholar
  4. Gaffal, K.P., Theiß, J.: The tibial thread-hairs ofAcheta domesticus L. (Saltatoria, Gryllidae). Zoomorphologie90, 41–51 (1978)Google Scholar
  5. Gaffal, K.P., Tichy, H., Theiß, J., Seelinger, G.: Structural polarities in mechanosensitive sensilla and their influence on stimulus transmission. Zoomorphologie82, 79–103 (1975)Google Scholar
  6. Gewecke, M.: Die Wirkung von Luftströmung auf die Antennen und das Flugverhalten der Blauen Schmeißfliege (Calliphora erythrocephala). Z. Vergl. Physiol.54, 121–164 (1967)Google Scholar
  7. Heinz, H.-J.: Vergleichende Beobachtungen über die Putzhandlungen bei Dipteren im allgemeinen und beiSarcophaga carnaria L. im besonderen. Z. Tierpsych.6, 330–371 (1949)Google Scholar
  8. Hendel, F.: Zweiflügler oder Diptera. In: Die Tierwelt Deutschlands und der angrenzenden Meeresteile, Bd. 18, 1. Dahl, F. (ed.). Jena: Gustav Fischer 1928Google Scholar
  9. Hepburn, H.R. (ed.): The insect integument. Amsterdam, Oxford, New York: Elsevier Sci. Publ. Co. 1976Google Scholar
  10. Hoffmann, C.: Bau und Funktion der Trichobothrien vonEuscorpius carpaticus L. Z. Vergl. Physiol.54, 290–352 (1967)Google Scholar
  11. Keil, T.: Die Makrochaeten auf dem Thorax vonCalliphora vicina Rob.-Desv. (Calliphoridae, Diptera). Zoomorphologie90, 151–180 (1978)Google Scholar
  12. Mann, D.W., Chapman, K.M.: Component mechanism of sensitivity and adaptation in an insect mechanoreceptor. Brain Res.97, 331–336 (1975)Google Scholar
  13. Matsumoto, D.E., Farley, R.D.: Comparison of the ultrastructure of stimulated and unstimulated mechanoreceptors in the taste hairs of the blowflyPhaenicia serricata. Tissue Cell10, 63–76 (1978)Google Scholar
  14. Nachtigall, W.: Die Kinematik der Schlagflügelbewegungen von Dipteren. Methodische und analytische Grundlagen zur Biophysik des Insektenfluges. Z. Vergl. Physiol.52, 155–211 (1966)Google Scholar
  15. Nachtigall, W.: Elektrophysiologische und kinematische Untersuchungen über Start und Stop des Flugmotors von Fliegen. Z. Vergl. Physiol.61, 1–20 (1968a)Google Scholar
  16. Nachtigall, W.: Gläserne Schwingen. München: Heinz Moos Verlag 1968bGoogle Scholar
  17. Neumann, H.: Untersuchungen zur Struktur und Elektrophysiologie mechanorezeptiver Sensillen auf den Vordertibien vonGryllus bimaculatus. Dissertation, Mathematisch-naturwissenschaftliche Fakultät der Universität Köln (1975)Google Scholar
  18. Neville, A.C.: Biology of the arthropod cuticle. Berlin, Heidelberg, New York: Springer 1975Google Scholar
  19. Reißland, A.: Electrophysiology of trichobothria in orb-weaving spiders (Agelenidae, Araneae). J. Comp. Physiol.123, 71–84 (1978)Google Scholar
  20. Rietschel, P.: Die Fliegen. In: Grzimek's Tierleben II, Insekten. Kindler Verlag 1969Google Scholar
  21. Sabaratnam, M.: The effect of digging on development of adult characters in blowfliesCalliphora erythrocephala. J. Insect Physiol.19, 2143–2154 (1973)Google Scholar
  22. Schlegel, P.: Die Leistungen eines Gelenkrezeptors der Antenne vonCalliphora für die Perzeption von Luftströmungen. Elektrophysiologische Untersuchungen. Z. Vergl. Physiol.66, 45–77 (1970)Google Scholar
  23. Schwartzkopff, J.: Mechanoreception. In: Physiology of insecta II. Rockstein, M. (ed.). New York, London: Academic Press 1974Google Scholar
  24. Schwind, R.: Visual system ofNotonecta glauca: A neuron sensitive to movement in the binocular visual field. J. Comp. Physiol.123, 315–328 (1978)Google Scholar
  25. Specht, U.: Funktionsmorphologie und Elektrophysiologie der Sinnesborsten auf den Cerci der SchabePeriplaneta americana. Dissertation, Naturwissenschaftliche Fakultät der Technischen Universität Carolo-Wilhelmina zu Braunschweig (1977)Google Scholar
  26. Spencer, H.J.: Analysis of the electrophysiological response of the trochanteral hair receptor of the cockroach. J. Exp. Biol.60, 223–240 (1974)Google Scholar
  27. Tautz, J.: Reception of medium vibration by thoracal hairs of caterpillars ofBarathra brassicae L. (Lepidoptera, Noctuidae) II. Response characteristics of the sensory cell. J. Comp. Physiol.125, 67–77 (1978)Google Scholar
  28. Thurm, U.: Die Beziehungen zwischen Reiz, Rezeptorpotential und Nervenimpulsen bei einzelnen mechanorezeptorischen Zellen von Bienen. Dissertation, Universität Würzburg (1962)Google Scholar
  29. Thurm, U.: Die Beziehungen zwischen mechanischen Reizgrößen und stationären Erregungszuständen bei Borstenfeld-Sensillen von Bienen. Z. Vergl. Physiol.46, 351–382 (1963)Google Scholar
  30. Thurm, U.: Das Rezeptorpotential einzelner mechanorezeptorischer Zellen von Bienen. Z. Vergl. Physiol.48, 131–156 (1964)Google Scholar
  31. Thurm, U.: An insect mechanoreceptor. Part II: Receptor potentials. Cold Spring Harbor Symp. Quant. Biol.30, 83–94 (1965)Google Scholar
  32. Thurm, U., Stedtler, A., Foelix, R.: Reizwirksame Verformungen der Terminalstrukturen eines Mechanorezeptors. Verh. Dtsch. Zool. Ges.1974, 37–41, Stuttgart 1975Google Scholar
  33. Vater, G.: Untersuchungen über die Morphologie des Nervensystems der Dipteren. Z. Wiss. Zool.167, 137–196 (1962)Google Scholar
  34. Vogel, G.: Verhaltensphysiologische Untersuchungen über den Weibchensprung des Stubenfliegenmännchens (Musca domestica). Z. Tierpsychol.14, 309–329 (1957)Google Scholar
  35. Whitten, J.M.: The fly ptilinum: Tactile receptors and their function at emergence. J. Linn. Soc. Zool.44, 725–730 (1963)Google Scholar
  36. Wolbarsht, M.L.: Electrical characteristics of insect mechanoreceptors. J. Gen. Physiol.44, 105–121 (1960)Google Scholar
  37. Zanforlin, M.: Perception of spatial relationships and pupation delay in fly larvae (Sarcophaga barbata). Anim. Behav.17, 323–329 (1969)Google Scholar
  38. Zumpt, F.: Calliphorinae. In: Die Fliegen der palaearktischen Region VIII. Lindner, E. (ed.). Stuttgart: Schweizerbart'sche Verlagsbuchhandlung 1956Google Scholar

Copyright information

© Springer-Verlag 1979

Authors and Affiliations

  • Joachim Theiß
    • 1
  1. 1.Institut für ZoologieRegensburgFederal Republic of Germany

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