Abstract: 【Aim】 This study aims to ascertain the feeding suitability of Taxodium distichum and Metasequoia glyptostroboides to Hyphantria cunea, by determining the performance of growth, development and population parameters of H. cunea when feeding on T. distichum and Me. glyptostroboides, as well as during host switching at different instars. 【Methods】 H. cunea larvae were reared on leaves of three host plants including Morus alba, T. distichum, Me. glyptostroboides (labeled as Ma, Td and Mg, respectively), and the host shift groups consisted of the 2nd, 4th and 5th instar larvae that were shifted from Mo. alba leaves to T. distichum leaves (labeled as Td2, Td4 and Td5, respectively), and the 4th instar larvae were shifted from Mo. alba leaves to Me. glyptostroboides leaves (labeled as Mg4). The growth and development performance and fecundity of H. cunea in various groups were observed and determined, and then the age-stage, two-sex life table was constructed. 【Results】 H. cunea displayed high adaptability on Mo. alba and T. distichum leaves. The larval duration of H. cunea in the Td group (33.38 d) was significantly longer than that in the Ma group (28.41 d), and the pupal duration and adult longevity of both genders in the Td group were significantly shorter than those in the Ma group. The larval duration of H. cunea in the Td2 group (34.22 d) were longer than that in Td4 and Td5 groups (33.19 and 28.92 d, respectively). The pupal duration and adult longevity of H. cunea of both genders in the three host-shift groups Td2, Td4, and Td5 were significantly longer than those in the Td group. The pupal weight and number of eggs laid per female adult of H. cunea in the Ma group were significantly greater than those in the Td group. The average numbers of eggs laid per female of H. cunea in the different age host-shift groups (Td2, Td4, and Td5) were greater than that in the Td group and less than that in the Ma group. The intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R₀) in the Ma group were significantly higher than those in the Td group. The life table parameters of test insects transferred from Mo. alba leaves to T. distichum leaves in the host-shift groups were between those in the Ma group and the Td group. Early instar larvae of H. cunea on Me. glyptostroboides leaves were unable to complete their life history. The Mg4 group in which the 4th instar larvae were from Mo. alba leaves and then shifted to Me. glyptostroboides leaves had significantly longer larval duration by 6.10 d than the Td4 group in which the 4th instar larvae were shifted to T. distichum leaves (Td group). The Mg4 group had shown the presence of the 8th instar larvae of H. cunea, but the female and male pupal duration in the Mg4 group was the shortest. The female and male pupal weight and the average number of eggs laid per female of H. cunea in the Mg4 group were also significantly smaller than those in the other groups. All the life table and population parameters in the Mg4 group were the lowest. 【Conclusion】 H. cunea showed high adaptability to T. distichum, and the lower the age at host shift, the developmental indexes of H. cunea were closer to those fed on T. distichum. The indoor rearing test showed that Me. glyptostroboides could not be used as a suitable host plant for H. cunea, but the edge dispersal populations may have developed adaptation to Me. glyptostroboides, and have expanded hosts during their spread to southern China.

Key words: Hyphantria cunea, Taxodiaceae plants, host shift, age-stage, two-sex life table, growth and development, fecundity