Host Selectivity and Adaptability of Rhoptroceros cyatheae to Alsophila spinulosa and Gymnosphaera metteniana var. subglabra

The host selectivity of Rhoptroceros cyatheae to different plants was determined using cage spawning and leaf plate method. The growth and development of larvae feeding on different tender leaves were observed. The relation between R. cyatheae and different host plants was analyzed. The results showed that R. cyatheae adults showed significant oviposition selectivity to Gymnosphaera metteniana var. subglabra. The number of eggs laid on Alsophila spinulosa and G. metteniana var. subglabra were (38.25 ± 8.27) and (67.38 ± 7.11), respectively. The 2^nd to 5^th instar larvae also showed a significant preference for feeding on G. metteniana var. subglabra. There is no significant difference in the development stage, adult longevity and emergence rate of larvae feeding on 2 plants. The mature larval stage and pupal stage of R. cyatheae which fed on A. spinulosa were significantly prolonged than that fed on G. metteniana var. subglabra, while the larval survival rate and pupation rate were significantly reduced. It can be seen that R. cyatheae has different selectivity among host plants. The oviposition selectivity of adults is consistent with the feeding selectivity of larvae. Compared with R. cyatheae feeding on A. spinulosa, the R. cyatheae feeding on G. metteniana var. subglabra has a higher fitness.