Abstract: 【Aim】 Pyrrhocoris tibialis is an important agricultural herbivorous pest with a wide host range. In this study, the feeding preference of P. tibialis to different plants was investigated, and the effects of physical characteristics and nutrients of host plants on the host selection behavior of P. tibialis adults were analyzed to explore the host selection behavior mechanism of P. tibialis from the perspective of host physical and chemical properties, so as to provide guidance for breeding of insect-resistant crops. 【Methods】 The feeding selectivity of P. tibialis adults to leaves of five host plants including Setaria italica, Sorghum bicolor, Vigna radiata, Glycine max and Zea mays was studied by free selection method, the taxis responses of P. tibialis to the odors from leaves of the five plants were detected by Y-tuber olfactometer, and the correlations between the leaf physical characteristics and contents of main nutrients in leaves of the five host plants and the feeding selectivity of P. tibialis were assayed and analyzed. 【Results】 P. tibialis adults showed significant difference in the feeding selection rate to leaves of the five host plants, in a descending order of millet > sorghum > mung bean = soybean > corn, and their percentages of taxis response to the odors from leaves of the five host plants exhibited the same results. Correlation analysis showed that the feeding selectivity of P. tibialis adults was significantly positively correlated with the blade aspect ratio, water content and abaxial pubescence density of leaves, with the correlation coefficients of 0.881, 0.884 and 0.906, respectively, whereas it was significantly negatively correlated with the changes in soluble sugar and total protein contents in leaves of host plants before and after being fed by P. tibialis adults, with the correlation coefficients of -0.915 and -0.951, respectively. Path analysis showed that the changes in abaxial pubescence density and total protein content in leaves of host plants were important determinants of host selectivity of P. tibialis. 【Conclusion】 There exist differences in feeding selection and taxis of P. tibialis adults to different host plants. The feeding selection of P. tibialis adults is related to the blade aspect ratio, abaxial pubescence density, water content, and the changes in soluble sugar and total protein contents in leaves of host plants.

Key words: Pyrrhocoris tibialis, host selectivity, taxis, tropism, physical traits; nutrients