Computed Tomography Based Three‐Dimensional Reconstruction of <i>Semanotus bifasciatus</i> Galleries: Implications for Precision Pest Management

ABSTRACT Semanotus bifasciatus Motschulsky (Coleoptera: Cerambycidae) is a destructive trunk‐boring pest of Cupressaceae plants. Its larvae form concealed galleries within the xylem, which are challenging to observe using traditional methods. This study combined computed tomography (CT) scanning with three‐dimensional (3D) reconstruction to characterize the spatial configuration, morphology, and blockage dynamics of S. bifasciatus galleries. We scanned infested wood sections of Platycladus orientalis using a 128‐slice spiral CT scanner and performed image segmentation and 3D reconstruction in MIMICS software to quantify gallery parameters, including length, volume, blockage ratio, and emergence hole dimensions. The 3D reconstructions showed that galleries were typically J‐shaped, spatially segregated, and evenly distributed. The mean gallery length was 24.83 ± 1.02 mm, the mean volume was 461.39 ± 31.98 mm 3 , and the mean proportion of gallery volume occupied by blockages was 22.3% ± 2.25%. The mean length and width of emergence holes were 4.61 ± 0.11 mm and 3.17 ± 0.08 mm, respectively. Larvae exhibited a nearly equal ratio of upward to downward boring (≈6:7) and a ‘forward boring and backward filling’ behaviour. During eclosion, adults pushed out part of the blockages to form emergence holes. Dissection confirmed morphological features but overestimated linear measurements compared to CT; however, dissection significantly overestimated gallery length ( t = −7.12, p &lt; 0.001) and emergence hole length ( t = −8.79, p &lt; 0.001) compared to CT. This study demonstrates that CT‐based 3D reconstruction enables non‐destructive, accurate visualization of S. bifasciatus gallery structures, provides insights into key pest behaviours, and offers technical support for precision control strategies. Moreover, it establishes a novel, non‐destructive method for the inspection and quarantine of this concealed pest.