Summary
Simultaneous recordings were made from 3 sensory units in an easily identifiable sensillum on the 12th antennal segment ofCarausius morosus. Impulse frequency (F) of one unit rose sharply when either the temperature (T) or the partial pressure of water vapor (Pw) was suddenly lowered. F of another rose sharply either when T was suddenly lowered or Pw was raised. F of the third was hardly affected by sudden changes in T but rose abruptly when Pw fell (Fig. 1). The reactions of the first may be explained by enthalpic cooling and is considered a cold cell. Those of the second may be attributed to changes in relative humidity (Hr) and is thus termed a moist cell. The third is taken to be the latter's antagonist, a dry cell.
A 90%-probability that a single moist cell of average differential sensitivity will correctly discriminate between two humidity levels is not reached until the difference between the two is 38% Hr. The dry cell requires a difference of only 7.5% (Table 1). The basis for discrimination is a single presentation of each level.
The power to discriminate Hr steps is better in both cell types. For a single moist cell of average differential sensitivity the difference required between the steps for a 90%-probability of correct discrimination is only 6.3% Hr; for the dry cell, 3.5% Hr. Basis for discrimination: a single presentation of each step. Step range: 5% to 55% Hr.
Similar content being viewed by others
Abbreviations
- F :
-
impulse frequency in impulses per second (imp/s)
- Hr orHR :
-
relative humidity in %
- Ps :
-
saturation pressure of water vapor in torr
- Pw :
-
partial pressure of water vapor in torr
- r :
-
correlation coefficient
- T :
-
temperature in °C
References
Altner H, Loftus R (1985) Ultrastructure and function of insect thermo- and hygroreceptors. Annu Rev Entomol 30:273–295
Altner H, Tichy H, Altner I (1978) Folded outer dendritic segments of a sensory cell within a thermo- and hygroreceptive sensillum of the insect,Carausius morosus. Cell Tissue Res 191:287–304
Diem K, Lentner C (eds) (1968) Wissenschaftliche Tabellen, 7th ed. Ciba-Geigy, Basel
Itoh T, Yokohari F, Tominaga Y (1984) Two types of antennal hygro- and thermoreceptive sensilla of the cricketGryllus bimaculatus (De Geer). Zool Sci 1:533–543
Loftus R (1976) Temperature-dependent dry receptor on antenna ofPeriplaneta. Tonic response. J Comp Physiol 111:153–170
Loftus R, Corbière-Tichané G (1981) Antennal warm and cold receptors of the cave beetle,Speophyes lucidulus Delar, in sensilla with a lamellated dendrite. J Comp Physiol 143:443–452
Tichy H (1979) Hygro- and thermoreceptive triad in antennal sensillum in the stick insect,Carausius morosus. J Comp Physiol 132:149–152
Yokohari F (1978) Hygroreceptor mechanism in the antennae of the cockroachPeriplaneta. J Comp Physiol 124:53–60
Yokohari F, Tateda H (1976) Moist and dry hygroreceptors for relative humidity of the cockroach,Periplaneta americana L. J Comp Physiol 106:137–152
Yokohari F, Tominaga Y, Tateda H (1982) Antennal hygroreceptors of the honey bee,Apis mellifera L. Cell Tissue Res 226:63–73
Waldow U (1970) Elektrophysiologische Untersuchungen an Feuchte-, Trocken- und Kälterezeptoren auf der Antenne der WanderheuschreckeLocusta. Z Vergl Physiol 69:249–283
Author information
Authors and Affiliations
Additional information
Dedicated to Prof. Dr. F. Schaller on the occasion of his 65th birthday
Rights and permissions
About this article
Cite this article
Tichy, H. Hygroreceptor identification and response characteristics in the stick insectCarausius morosus . J. Comp. Physiol. 160, 43–53 (1987). https://doi.org/10.1007/BF00613440
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00613440