Variations in Wing Venation of Apis cerana in Kalimantan and Related Islands in Sundaland Based on Geometric Morphometrics

Abstract

Apis cerana has a broad distribution across mainland Asia and exhibits high variation in wing venation. However, studies on wing venation variation in the Indonesian archipelago have mainly focused on Sumatra and Java. Therefore, this study aimed to analyze wing venation variation in Kalimantan and the relationship between A. cerana in the Sundaland region, including Sumatra and Java. Geometric morphometric methods were applied using 19 wing venation landmarks, followed by Principal Component Analysis (PCA) and Neighbor-Joining (NJ) tree analysis. The results showed that A. cerana from South Kalimantan exhibited the greatest variation in wing shape, whereas samples from West Kalimantan displayed relatively conserved wing size and shape, as indicated by low variation. Landmarks 11, 16, and 17 contributed a high value of wing venation variation within A. cerana Kalimantan and across Sundaland. The PCA revealed that A. cerana from Kalimantan was generally separated from those of Sumatra and Java. This pattern was supported by the NJ tree, which showed distinct clustering between Kalimantan and the other islands, although several samples from Banten and Jambi clustered with Kalimantan. These findings highlight the biogeographic pattern of A. cerana across Sundaland and the potential of wing-venation geometric morphometrics for digital species identification in Indonesia.