Certain effects of different spectral colors on some biological parameters of the two-spotted spider mite, Tetranychus urticae

Abstract

Certain effects of different spectral light colors were studied on some biological attributes of the two-spotted spider mite, Tetranychus urticae. Rearing of animals was carried out under conditions of 27±0.5°C; 60% R.H. and 16 L/8 D photoperiod on Sweet Potato leaves. Thus, 5 artificial light colors were applied under controlled laboratory conditions on these animals: blue, red, green, yellow and white Neon. After treatment, the highest number of deposited eggs/female was observed by using the blue color (14.9±0.5 eggs/female) while the lowest one was the yellow (3.1±0.2 eggs/female) compared to 9.9±0.4 eggs/female for the control group. On the other hand, diapause incidence was observed for the target females under conditions of 18±2°C; 60±2% R.H. and the light and dark periods were set at 8 L/16 D, respectively. Results showed that white Neon color caused the highest percentage of diapausing females (88.66±1.8%) followed by green color (78±3.5%), yellow (68.66±2%), the blue color with (54±2%), and finally none of them entered diapause under red color. Results were analyzed and discussed for the aforementioned important economic pest animals.