Abstract:

To determine the regulation effect of linearly polarized spectrum light with polarization detection vector on the polartaxic response of locusts (Locusta migratoria), the self-made linearly polarized light modulation module and test device for the polarization response of locusts were adopted. The influence of illuminance of linearly polarized spectrum on the polarization response of locusts was also examined to determine the sensitivity mode of locusts. It was shown that the polartaxic response of locusts presented chord function response characteristics to polarization detection vectors with clockwise and anticlockwise direction, and the spectral properties determined the specific sensitivity of locusts. The linearly polarized spectrum intensity affected the sensitive polartaxic vision distance vector of locusts. At 100 lx, the induced polartaxic aggregation response sensitivity of locusts by polarized violet spectrum was stronger, while the induced visual trend sensitivity by polarized ultraviolet spectrum was stronger. At 1 000 lx or under the same light energy, the induced polartaxic response sensitivy of locusts by polarized violet spectrum was stronger. With the changes of illuminance of linearly polarized light, the sensitive polartaxic vector mode of locusts was reset: the changes of illuminance of the linearly polarized violet light had enhancement effect, the changes of illuminance of the linearly polarized ultraviolet light had regulatory effect, while the changes of illuminance of the linearly polarized blue, green light had inhibition effect. Moreover, the antagonism sensitivity of locusts to the polarization detection vector (±180°, 0° and±90°) was related to the illuminance of the linearly polarized spectrum. The inhibition effect of the weak polarization detection light under±90°, and the reinforcing effect of the strong polarization detection light under±180° and 0° were related to the illuminance or the light distance stimulus of linearly polarized spectrum. At 1 000 lx, the polartaxic response sensitivity of locusts was the strongest under±90° with violet spectrum, followed by orange spectrum under±180°. Under the same light energy, the polartaxic aggregation response sensitivity and the visual trend of locusts were the strongest under±180° with violet spectrum, followed by the same spectrum under 0°. These findings could provide references to reveal the mechanism of polarization response of locusts, and to guide the invention of the new light for the control of locusts.

Key words: Locusta migratoria, linearly polarized light, polarization detection vector, polartaxic sensitivity, response characteristics