Niche analysis of the main seed pests of Quercus liaotungensis

Author of the article:LIAN Jun-Hua, QIU Ya-Lin, BAI Ying-Tong, GUO Zi-Fa, XU Zhou-Zhou, JIN Yi-Kan

Author's Workplace：Gansu Ziwuling Forestry Administration Ningxian Branch, Ningxian 745200, China

Key Words：Quercus liaotungensis; seed pests; community composition; mixed harm; niche

Abstract：[Objectives]  To investigate the community composition and damage caused by seed pests of Quercus liaotungensis, including the degree of utilization of various resources by these pests and their competitive coexistence with other pest species. [Methods]  From mid-April to October 2020, standard sampling methods were used to identify three test sample sites, after which the diagonal line 5 point sampling method was used to select 15 sample trees, within which the tree stratum sampling method was used to collect seed samples from 2 m × 2 m squares situated at three levels in the south, east, west and northern aspects of the canopy. Seeds samples were brought back to the laboratory and acorns were dissected under a stoichiometric microscope. The species and number of larvae in seeds were counted and classified into different resource sequences and grades. Niche analysis was conducted using Levin’s niche width index and the Pianka niche overlap index, and the significance of differences analyzed using Duncan's multiple test method. [Results]  Curculio dentipes had the largest spatial niche width (0.999 2±0.000 3), Dichocrocis punctiferalis the largest trophic niche width (0.996 1±0.001 5) and Curculio dieckmanni the largest temporal niche width (0.966 8±0.004 9). The mixed damage rate was (10.72%) and the highest three-dimensional niche overlap (0.881 9±0.002 3) was between Curculio dentipes and Curculio sp.; significantly higher than that between other species (P < 0.01). [Conclusion]  C. dentipes, C. dieckmanni and D. punctiferalis have respectively the largest spatial resources, the longest time resources and the most nutritional resources. These species are widely distributed and often cause serious seed damage. The following pairs of species; C. dentipes and Curculio sp., C. dentipes and C. glandicolana, C. dieckmanni and D. punctiferalis, D. punctiferalis and C. glandicolana and C. dentipes and D. punctiferalis, are sympatric in both space and time and often causing serious damage to Q. liaotungensis seeds.