Fig. 9

Two stages of internal genitalia during copulation (volume rendering and false colour). a, b Couple fixed at 20 min after the onset of copulation (first stage); the diverticulum and vesica are inflated by haemolymph, only semiliquid materials are transferred. c, d Couple fixed at 60 min after the onset of copulation (second stage; sterigma omitted); the diverticulum is relaxed; the rigid materials occupy the vesica and cause stretching of the curvatures of the ductus bursae. a, c Ventral view. b, d Lateral view. 1 corpus material, 2 sperm sack material, 3 collum material. Scale bar 1 mm