Abstract :
Colour vision is common phenomenon in living animals, but varies in insect species, depending on their vision sensitivity and photoreceptors involved. The sensitivity of the photoreceptor is determined through the absorption of visual colour pigments expressed. Photoreceptors are involved in filtering pigments, transverse wavelength, retinal image and colour signals. We have evaluated the colour attraction of two important stored grains insects, Red flour beetle (Tribolium castaneum H) and Pulse beetle (Callosobruchus chinensis L) to determine their visual sensitivity toward various colour surfaces. The data was recorded after 24hrs of releasing the insects in a chamber in which various colour surfaces were provided. The results showed that the T. castaneum was highly attracted toward green colour with maximum (17.3%) and (8.7%) of insects observed outside and inside the bags respectively. Whereas, minimum (4.3%) and (3.0%) T. castaneum found outside and inside the blue colour bags respectively. Similarly, C. chinensis was greatly attracted toward blue colour with the maximum (16.0%) and (7.7%) insects found attached outside and inside the bags respectively. Whereas, minimum (9.0%) and (2.0%) C. chinensis were recorded outside and inside the black colour bags respectively.
Keyword :
Tribolium castaneum; Callosobruchus chinensis; stored grains pest, colour surfaces; attraction.