The larvae of hymenopteran Symphyta are eruciform, with several pairs of abdominal prolegs in addition to three pairs of thoracic legs. However, it is still controversial whether these abdominal prolegs are serially homologous with the thoracic legs. Here we studied the embryonic development of the larval appendages of the large rose sawfly Arge pagana (Panzer, 1798) to investigate the origin and homologous relationship of the abdominal prolegs of Argidae. The results show that paired swellings (proleg primordia) on the embryonic abdomen are not aligned with the thoracic legs, but are slightly closer to the midventral line. During the embryonic development, the thoracic leg primordia are differentiated into six segments, while the abdominal appendage primordia remain unsegmented and eventually develop into conical prolegs. The abdominal prolegs of larval A. pagana are likely developed from the endites of the primary embryonic appendages, and the paired anal prolegs arise from the eleventh abdominal segment. Therefore, the abdominal prolegs of sawfly larvae are very likely to have an appendicular nature but not the main axes of appendages.

膜翅目共生体的幼虫为卵形，除了三对胸腿外还有几对腹前臂。然而，这些腹部前腿是否与胸腿系列同源仍存在争议。在这里，我们研究了大型玫瑰锯蝇Arge pagana幼虫附肢的胚胎发育（Panzer，1798）来研究Argidae腹部前腿的起源和同源关系。结果显示，胚胎腹部成对的肿胀（前腿原基）与胸腿不对齐，但稍微靠近腹中线。在胚胎发育过程中，胸腿原基可分为六个部分，而腹部附件原基仍未分割，最终发育成圆锥形前腿。幼虫A.pagana的腹前突很可能是从初级胚胎的附属器官发育而来的，而成对的肛门前突则是从第十一腹节产生的。因此，锯蝇幼虫的腹前部很可能具有阑尾性质，但不具有阑尾主轴。