Influence of light intensity on the body colour of Prodenia litura (Fabricius) larvae based on computer visualization
Author of the article:LI Jin-Jie1 GONG Bi-Ya1, 2 WEN Yi-Chun1 PENG Yun-Peng1YANG Hong-Zhang1 WEN Li-Zhang1**
Author's Workplace：(1. Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha 410128, China; 2. Hunan Horticultural Institute, Changsha410125, China)
Key Words： computer vision, Prodenia litura (Fabricius), body colour, numeralization, illuminace
Abstract： [Objectives] To reveal the influence of illumination on the body colour of Prodenia litura (Fabricius) larvae, a new system of evaluating insect body colour was established. [Method] Based on computer vision detection technology, the change in body colour of P. litura larvae over successive days and the effect of illumination on the change in body colour were evaluated by assigning colours a numerical value. [Results] Brightness (B) and colour index (CI) decreased gradually of larvae over successive days, while the deviation coefficient (BDV) increased. The dominant colour, green, transformed gradually into red, all color parameters of subjective colour were significantly different among larvae of different ages (P<0.01). The brightness (B) and deviation coefficient (BDV) of body colour was influenced by light with low light intensity (0- 1 000 lx), while colour index (CI) and normalized RGB value were influenced by age. At high light intensity(over 1 000 lx), all parameters of subjective colour were influenced by age more than light; the effect threshold of light intensity on body-colour was 1 000 lx, at this threshold, the brightness (B), colour index (CI) and differentiation coefficient of body colour increased with light intensity whereas the deviation coefficient (BDV) and delta-RGB (D) decreased. [Conclusion] Light intensity mainly affects the light and shade of body colour on P. lituralarvae but had little effects on the degree of colour; the effect threshold of light intensity was 1 000 lx.