Abstract: 【Aim】 To clarify the host selectivity of Tuta absoluta to different tomato varieties, and analyze the correlations between the host selectivity of T. absoluta and the physical and chemical characteristics of the leaves of different tomato varieties, so as to provide a theoretical basis for the green precise control of T. absoluta and the breeding of insect-resistant tomato varieties.【Methods】 The feeding selection rates and consumed area of the 3rd instar larvae of T. absoluta to the leaves of five tomato varieties (Qianxi, Dafen, Dahei, Xiaolv and Huang′aisheng) were measured by leaf disc method, the numbers of eggs laid by T. absoluta adults on per leaf of the five tomato varieties were detected by caging method, the physical and chemical characteristics of the leaves of five tomato varieties were measured by grid method and colorimetric method, and the correlations between the feeding selection rate of the 3rd instar larvae of T. absoluta or the number of eggs laid by female adults on per leaf and the physical and chemical characteristics of the leaves of different tomato varieties were analyzed by Pearson’s method.【Results】 The results of host selectivity showed that when T. absoluta larvae fed on the leaves of the five tomato varieties for 6, 12, 24 and 48 h, their feeding selection rates were ranked in a descending order as follows: Dafen>Qianxi>Dahei>Xiaolv>Huang′aisheng. When T. absoluta adults laid eggs on the leaves of the five tomato varieties for 24, 48 and 72 h, their numbers of eggs laid on per leaf were ranked in a descending order as follows: Dahei>Qianxi>Dafen>Huang′aisheng>Xiaolv, Dahei>Huang′aisheng>Qianxi>Dafen>Xiaolv, and Dahei>Huang′aisheng>Dafen>Qianxi>Xiaolv, respectively. The results of Pearson correlation analysis showed that the feeding selection rate of the 3rd instar larvae of T. absoluta was significantly negatively correlated with the protein content in the leaves of different tomato varieties when fed for 12 h. When T. absoluta adults laid eggs for 48 and 72 h, their numbers of eggs laid on per leaf were significantly positively correlated with the chlorophyll b content and total chlorophyll content in the leaves of different tomato varieties.【Conclusion】 The physical and chemical characteristics of the leaves of five tomato varieties (Qianxi, Dafen, Dahei, Xiaolv and Huang′aisheng) have significant effects on the host selection of T. absoluta. Based on the correlation analysis, T. absoluta larvae prefer to feed on the leaves of tomato varieties with low protein content, and adults prefer to lay eggs on the leaves of tomato varieties with high chlorophyll content.

Key words: Tuta absoluta, host selection, tomato variety, Pearson correlation analysis, physical and chemical characteristics