INVESTIGADORES
FARINA Walter Marcelo
artículos
Título:
The regulation of the distance to dummy flowers during hovering flight in the hawk moth Macroglossum stellatarum.
Autor/es:
FARINA, WALTER M; VARJU, D; ZHOU, Y
Revista:
JOURNAL OF COMPARATIVE PHYSIOLOGY A-SENSORY NEURAL AND BEHAVIORAL PHYSIOLOGY
Editorial:
Springer
Referencias:
Lugar: Berlin; Año: 1994 p. 239 - 248
ISSN:
0340-7594
Resumen:
While collecting nectar in hovering flight the
European hawk moth Macroglossum stellatarum efficiently
regulates its distance relative to flowers that are
shaken by wind. This can be demonstrated in laboratory
experiments by moving dummy flowers (blue cardboard
disks) towards and away from the feeding animal (Fig. 1).
2. Distance regulation is predominantly mediated by
visual cues. Mechanoreceptors on the proboscis appear
to contribute little to the response.
3. Movements of dummy flowers can be simulated by
expanding and contracting a pattern projected onto a
screen. With this technique we investigated the dynamical
properties of the servo mechanism underlying distance
regulation. The system behaves as a bandpass filter
with corner frequencies of 0.15 and 5 Hz (Figs.2,3).
4. When a high-speed ramp-like movement of the
flower is simulated, there is an asymmetry in the response.
During simulated approach the reaction is phasic-
tonic with a pronounced overshoot at the beginning,
during simulated retraction it remains tonic (Fig.5B,C).
5. During distance regulation the animals compensate
for the speed of the edge of the projected pattern. Distance
regulation improves substantially when the number
of stimulated elementary movement detectors is increased
through increasing the number of contour lines
by projecting concentric rings instead of a homogeneous
disk (Figs.7, 8).
regulates its distance relative to flowers that are
shaken by wind. This can be demonstrated in laboratory
experiments by moving dummy flowers (blue cardboard
disks) towards and away from the feeding animal (Fig. 1).
2. Distance regulation is predominantly mediated by
visual cues. Mechanoreceptors on the proboscis appear
to contribute little to the response.
3. Movements of dummy flowers can be simulated by
expanding and contracting a pattern projected onto a
screen. With this technique we investigated the dynamical
properties of the servo mechanism underlying distance
regulation. The system behaves as a bandpass filter
with corner frequencies of 0.15 and 5 Hz (Figs.2,3).
4. When a high-speed ramp-like movement of the
flower is simulated, there is an asymmetry in the response.
During simulated approach the reaction is phasic-
tonic with a pronounced overshoot at the beginning,
during simulated retraction it remains tonic (Fig.5B,C).
5. During distance regulation the animals compensate
for the speed of the edge of the projected pattern. Distance
regulation improves substantially when the number
of stimulated elementary movement detectors is increased
through increasing the number of contour lines
by projecting concentric rings instead of a homogeneous
disk (Figs.7, 8).
Macroglossum stellatarum efficiently
regulates its distance relative to flowers that are
shaken by wind. This can be demonstrated in laboratory
experiments by moving dummy flowers (blue cardboard
disks) towards and away from the feeding animal (Fig. 1).
2. Distance regulation is predominantly mediated by
visual cues. Mechanoreceptors on the proboscis appear
to contribute little to the response.
3. Movements of dummy flowers can be simulated by
expanding and contracting a pattern projected onto a
screen. With this technique we investigated the dynamical
properties of the servo mechanism underlying distance
regulation. The system behaves as a bandpass filter
with corner frequencies of 0.15 and 5 Hz (Figs.2,3).
4. When a high-speed ramp-like movement of the
flower is simulated, there is an asymmetry in the response.
During simulated approach the reaction is phasic-
tonic with a pronounced overshoot at the beginning,
during simulated retraction it remains tonic (Fig.5B,C).
5. During distance regulation the animals compensate
for the speed of the edge of the projected pattern. Distance
regulation improves substantially when the number
of stimulated elementary movement detectors is increased
through increasing the number of contour lines
by projecting concentric rings instead of a homogeneous
disk (Figs.7, 8).