The scarab beetle is an herbivorous pest that causes considerable damage to various agricultural crops. The characteristics of the hind wings have rarely been utilized as indicators for species identification, particularly within the genus Holotrichia. To evaluate the potential of hind wing traits in species identification and gender differentiation, we extracted 25 landmarks from 125 samples of three beetle species (Holotrichia diomphalia, H. titanis, and H. oblita) using TPSDig2 v2.31, with each hind wing image analyzed three times. These landmarks were employed to analyze variations in wing size and shape among species and sexes, and a cross-validation test was conducted in MorphoJ v1.06 to assess classification accuracy. The results demonstrate that both female and male samples exhibit significant differences in wing size and shape variations across species, but not between sexes. Allometry accounts for 16.92% and 25.35% of total shape variation in females and males, separately. After correcting for allometric effects, classification accuracy improves for these beetles. From further analysis, it can be observed that female wings exhibit a wider and shorter morphology in comparison to the more slender and elongated wings of males. In terms of interspecific differences, H. oblita females displayed narrow and elongated wings, whereas H. diomphalia females had a more rectangular wing shape. Among males, the degree of wing narrowness decreased in the order of H. oblita, H. titanis, and H. diomphalia.

Reliable traits are needed for identification of tea (Camellia sinensis) cultivars, yet the stability of leaf morphology and color across leaf positions remains unclear. This study evaluated inter-cultivar variation and positional stability in leaf morphological, RGB color, and SPAD traits in six predominant cultivars. One-year-old shoots were sampled in a completely randomized design, and five fully expanded leaves below the apical bud were analyzed. SPAD values were measured with a chlorophyll meter, and scanned images were used to extract contour and RGB traits. Data were analyzed using ANOVA, correlation analysis, PCA, and discriminant analysis. Leaf morphology differed among cultivars and leaf positions, with significant cultivar-by-position interactions; however, the width-to-length ratio differed among cultivars but remained stable across positions in these cultivars. SPAD values increased with leaf position and were strongly associated with RGB components, being negatively correlated with R and G and positively correlated with B. Morphological traits explained 52.988% of total variance in PCA and yielded 64.6% overall classification accuracy, with LaoHan showing the highest accuracy (83.3%). Misclassification was concentrated among genetically similar cultivars. These findings suggest that stable leaf shape proportions and SPAD–RGB relationships provide useful descriptors, whereas genetic relatedness limits morphology-based cultivar identification under the present conditions.