Sensilla chaetica
The sensilla chaetica of the adult mandibular palpus has two subtypes
(SCh IV, SCh V). SCh IV is found on segments 2, 3 and 4 of the
mandibular palpus, while SCh V is found on segments 2 and 3 of the
mandibular palpus. These two inductor subtypes differ considerably in
length and basal width (Table 5).
The lengths of SCh V and SCh IV of the female mandibular palpus were
both longer than those of the males, but there were no significant
differences in width. Quantitatively, females outnumbered males only in
SCh IV (♀ = 226.98 ± 12.67 μm, ♂ = 81.31 ± 4.93 μm, t = 10.71,P < 0.01) in segment 4 of the mandibular palpus,
whereas males outnumbered females in SCh IV (♀ = 321.60 ± 1.21, ♂ =
24.60 ± 1.47, t = 7.58, P < 0.01), and SCh V (♀
= 22.00 ± 2.79, ♂ = 48.60 ± 4.12, t = -5.35, P <
0.01) were significantly more numerous in males than in females, and SCh
IV (♀ = 193.60 ± 6.52, ♂ = 226.60 ± 5.84, t = -3.77, P< 0.05) and SCh V (♀ = 14.80 ± 3.38, ♂ = 31.60 ± 1.44,t = -4.57, P < 0.01) in segment 3 of the
mandibular palpus were significantly more numerous in males than in
females. Böhm’s bristle sensor (Bb) also occurred at the junction of the
base of the first segment with the mouthparts. There were no significant
numerical differences in Bb between males and females in the labial
palpus and mandibular palpus as a whole (Fig. 5).