Böhm bristles
The Böhm’s bristle sensor (Bb) also founded that it just exists at the junction of the base of the 1st segment with the mouthparts.There were no significant numerical differences between males and females in the labial papuls and mandibular papuls as a whole (Figs. 5). The overall variability in morphological characters was also not significant, except for the presence of a significantly wider Bb base width (♀ = 2.49 ± 0.07 μm, ♂ = 1.92 ± 0.07 μm, t = 5.81, P < 0.01) in the mandibular palpus of females than males (Tables 5).