Population trends of three endangered butterflies under the influence of forest restoration and human disturbance in Qinling Mountains

In order to explore the impact of forest restoration on butterfly survival, the long-term changes in the number of butterfly host plants and larvae were investigated by sample survey from 2011 to 2025, and the threat factors were analyzed. Threat factors were provided. The results showed that the number of host plants and larvae of the three specialist butterflies, namely the Luehdorfia taibai , Luehdorfia chinensis huashanensis , Bhutanitis thaidina decreased to varying degrees. Among them, the density of the host plant of Luehdorfia taibai decreased from 2.23 plants/㎡ in 2011 to 0.13 plants/㎡ in 2023, and no eggs and larvae were found in 2023-2025. The density of the host plant of the Luehdorfia chinensis huashanensis decreased by 71.33%, and the average insect plant rate decreased by 37.03%. The density of host plants of Bhutanitis thaidina decreased by 65.52%, and the rate of insect plants decreased by 43.29%. The main reason for the decline is that the forest is too dense, which leads to the disappearance of glades, the dense forest restricts the oviposition of adults, and the lack of heat under the forest affects the development of larvae. Artificial excavation leads to insufficient number of host plants, and the larvae on the leaves are sunburned. In addition, there is interspecific competition, predation by natural predators, climate change, etc. Population conservation and restoration strategies include habitat management, protection of host plants, in-situ artificial culture, and public education.