Tenebrio beetle magnetic orientation is sensitive to wavelength of light and inclination.
|Year of publication||2007|
|Type||Article in Proceedings|
|Conference||The 8th Congress of the International Society for Neuroethology|
|MU Faculty or unit|
|Keywords||insect; magnetoreception; light; inclination|
|Description||Numerous animals were reported to use the magnetic field of the Earth as an orientation cue. Different animals utilize the geomagnetic information differently. Some perceive the polarity of geomagnetic vector directly (polarity compass) while other species derive the difference between Northward and Southward directions from the dip of the geomagnetic vector (inclination compass). Besides, some animals show shift of their magnetic bearing when illuminated by lights of diverse colours. Such behavioural characteristics of compass orientation may tell more about possible neural mechanism(s) of magnetic perception. A number of insect species are known to use magnetic compass for orientation. However, very little is known about characteristics of their magnetic compasses. In the present study, the mealworm beetle Tenebrio molitor was tested for sensitivity of its magnetic compass orientation both to reversal of the inclination of the magnetic vector and the change of the illumination colour. We used a standart conditionig protocol: In both experiments, in the first step, animals were trained to memorize the magnetic position of a light source attracting them. In the following step, beetles released individually in the centre of a circular arena showed preference of the direction which corresponded to the magnetic bearing previously learned. We found significant impacts of both factors changed between the training and the test: inclination reversal and the change from 390 nm to 500 nm of the illuminating light wavelength. The results show Tenebrio compass as an inclination-sensitive and wavelength-sensitive and may contribute to the discussion about what modes of sensory transduction are used in insect magnetoreception.|