Comparison of Mouthpart Sensilla of Two Rapeseed Pests (Xenostrongylus variegatus and Brassicogethes aeneus) Using Scanning Electron Microscopy (Coleoptera: Nitidulidae).

Xenostrongylus variegatus (Nitidulidae: Nitidulinae) and Brassicogethes aeneus (Nitidulidae: Meligethinae) are two significant rapeseed pests in China. The former primarily feeds on leaves, while the latter exclusively targets flowers. Insect mouthparts are essential for feeding, with sensilla playing a critical role in food detection. This study compares the mouthpart sensilla of these two pests using scanning electron microscopy for the first time. Results revealed seven types (23 subtypes) of sensilla in male X. variegatus, seven types (21 subtypes) in female, and seven types (18 subtypes) in both male and female B. aeneus. Differences in the types, quantities, and distributions of sensilla were noted, with preliminary inferences made regarding their functions. These findings provide a foundation for further research into feeding behaviors, sensory systems, and integrated pest management strategies for rapeseed pests.