Temporal and spatial niches of two sympatric Tomicus species pests of Pinus yunnanensis Faranch
Author of the article:SHEN Shao-Wei1** LUO You-Qing1*** YU Lin-Feng1 LU Wen-Juan2 HAN Xiang-Guo2 Ren Li-Li1
Author's Workplace:1. Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China; 2. The Forest Service of Xiangyun County, Dali 672100, China
Key Words:Tomicus yunnanensis Kirkendall & Faccoli, Tomicus minor Hartig, Pinus yunnanensis Faranch, temporal niche, spatial niche
Abstract:
[Objectives] Tomicus yunnanensis Kirkendall & Faccoli and Tomicus minor Hartig are two wood boring pests that endanger pine species of the genus Pinus L. in southwest China. These species are often both found on Pinus yunnanensis Faranch where they feed on the shoots and bore into the trunk, causing tree death, ecological damage and economic loss. [Methods] We investigated the temporal and spatial niches of these two species during the “branch to trunk” and “trunk to branch” periods by conducting sampling at different field sites, stem dissection and analysis. [Results] After the “branch to trunk” period, T. minor is mainly distributed in the mid to bottom sections of trunks, whereas T. yunnanensis is mainly found on the upper trunk. T. yunnanensis was mainly found in branches but T. minor was predominantly found in trunks. The “trunk to branch” period began in mid-May, at which time the two species begin to emerge simultaneously. The peak of T. yunnanensis emergence occurred around June 1st and the peak of T. minor emergence was about ten days later. The two species were randomly distributed during the “trunk to branch” period. The temporal and spatial niche widths of the two species were broad, indicating that both species are active for a relatively long period and can therefore inflict damage on P. yunnanensis over a relatively long period of time. Spatial niche overlap between the two species was small, indicating that their distribution on P. yunnanensis differed, reducing interspecific competition. However, the temporal niche overlap of the two species was large, which indicates that they both damage to P. yunnanensis during the growing season, and they have almost the same emergence period. [Conclusion] Although the temporal overlap between the two species was high, their spatial overlap within individual P. yunnanensis trees was low. These results clarify the spatial and temporal niches of these two Tomicus species and provide important information to support remote sensing monitoring of outbreaks of these pests in P. yunnanensis forests.