In this study, the third-stage larva and puparium of the copper-backed fly, Platycheirus (Carposcalis) chalconota (Philippi, 1865) are fully described using stereomicroscopy and scanning electron microscopy from material collected in peach orchards of central-west Argentina. The immature stages of P. chalconota were compared with the third-stage larva and puparium of the best-studied species in the genus Platycheirus scutatus (Meigen, 1822); as well as with the only known Carposcalis immature stages description available for the Neotropical region namely Platycheirus stegnus (Say, 1829). New data on trophic interactions and larval habitats are given: P. chalconota larvae were found feeding on the aphid’s species Uroleucon sonchi (Linnaeus, 1767) (large sow thistle aphid) and Hyperomyzus lactucae (Linnaeus, 1758) (blackcurrant-sow thistle aphid) in low vegetation as Sonchus oleraceus (common sow thistle); the species was also found feeding on Myzus persicae (Sulzer, 1776) (green peach aphid) in high vegetation as Prunus persicae (L.) Stokes (Peach trees). The third larval stage and puparium of P. chalconota are described and illustrated for the first time improving substantially the knowledge about the immature stages and natural history of Neotropical Platycheirus, constituting also a baseline for future comparative morphological studies. Despite the efficiency of P. chalconota in the biological control of pests has not been assessed, we think that relevant data presented here can be used in pest management of peach orchards and suggest P. chalconota as an excellent candidate for future studies on the life cycle, prey consumption, efficiency, artificial rearing, and its potential importance as pollinators of Peach crops.

在这项研究中，使用立体显微镜和扫描电子显微镜从阿根廷中西部桃园收集的材料中充分描述了铜背蝇Platycheirus ( Carposcalis ) chalconota (Philippi, 1865) 的第三阶段幼虫和蛹。将P. chalconota的未成熟阶段与Platycheirus scutatus属中研究最好的物种的第三阶段幼虫和蛹进行比较（Meigen，1822）；以及唯一已知的可用于新热带地区的 Carposcalis未成熟阶段描述，即Platycheirus stegnus (Say, 1829)。提供了有关营养相互作用和幼虫栖息地的新数据：发现P. chalconota幼虫 在低植被如Sonchus oleraceus（普通母猪蓟）中以蚜虫的物种Uroleucon sonchi (Linnaeus, 1767) (大型母猪蓟蚜) 和Hyperomyzus lactucae (Linnaeus, 1758) (blackcurrant-sow thistle aphid) 为食; 该物种还被发现以桃蚜 ( Myzus persicae (Sulzer, 1776) （绿桃蚜虫）为食）在高植被中，如Prunus persicae (L.) Stokes（桃树）。首次描述和说明了P. chalconota的第三个幼虫阶段和蛹，大大提高了对新热带Platycheirus未成熟阶段和自然历史的认识，也构成了未来比较形态学研究的基线。尽管尚未评估P. chalconota在害虫生物防治中的效率，但我们认为此处提供的相关数据可用于桃园的害虫管理，并建议P. chalconota作为未来生命周期研究的绝佳候选者、猎物消耗、效率、人工饲养及其作为桃作物传粉媒介的潜在重要性。