| Abstract: | The external structure of the 1st (AS1) and 4th abdominal segments (AS4) of Pieris rapae is described in terms of pattern of shallow grooves on the cuticle. Both segments have 5 dorsal costae, 3 ventral costae, and an antero-posterior line in addiction to the dorsal and ventral intersegmental folds and a spiracle. AS4 has a pair of prolegs. The musculatures of AS1 and AS4 consist of 44 and 51 muscles, respectively. As in thoracic ones, most attachments of the muscles are located on the cuticular grooves. AS1 and AS4 have similar musculatures. Common to both segments are 89% of AS1 muscles and 84% of AS4 muscles. AS1 has 6 muscles homologous to proleg ones of AS4, including proleg retractors and plantar retractors. Comparison of the musculature of proleg-bearing abdominal segments among different species shows that abdominal musculature of lepidopteran larvae has major homologous and minor specific muscles. From the muscle attachment sites, the role of each muscle is inferred for contraction and bending of the body, lifting up its venter, taking off the crockets from the substrate, and retraction, lateral abduction, and anterior movement of the proleg. |
