In a wind tunnel the team compared the color preference for western flower thrips to four types of color plates (clear, white, blue and yellow) applied with two types of glue (diffuse Stikem versus clear D41). Further the results for blue and yellow preference were validated in two greenhouses.
In the wind tunnel, the team found a clear preference of yellow over blue when a clear glue (D41) was used. However, with a more diffuse (whitish) glue (Stikem) the preference for yellow over blue disappeared, whereby the attraction to yellow decreased (58%) while the attraction to blue increased (65%). In the greenhouses, the team found similar effects as in the wind tunnel with a decrease in attraction to yellow (35%) and increase in attraction to blue (32%) for Stikem compared to D41. Light measurements showed an increase of 18% of blue, 21% of violet light, 8% of yellow and 9% of green light reflected on the yellow Stikem trap versus the yellow D41 trap. On blue plates there was only 4% increase of blue light, 8% decrease of yellow light reflected when Stikem glue was used compared to D41 glue.
It is not yet clear if the change of light reflection ratio blue/yellow caused by the glue type plays a role in the change of attraction. The reflective properties of glue are so far an unknown factor in color choice and may explain partially the different results on color preference. A small review on thrips color preference is discussed to determine possible other factors of influence on color choice.
Read the complete article at www.researchgate.net.
Van Tol, Rob & Tom, Jolanda & Roher, Monika & Schreurs, Anne & van Dooremalen, Coby. (2021). Haze of glue determines preference of western flower thrips (Frankliniella occidentalis) for yellow or blue traps. Scientific Reports. 11. 6557. 10.1038/s41598-021-86105-5.