【目的】 近年来，有关昆虫取食降解塑料废弃物的研究备受关注。本文研究大麦虫Zophobas atratus幼虫取食塑料后的生长发育、肠道内微生物菌群的变化，以及经过肠道后塑料的重量损失和分子量的变化，为进一步研究大麦虫幼虫降解塑料废弃物提供科学依据。【方法】 以聚苯乙烯泡沫和聚乙烯发泡棉饲喂大麦虫幼虫，测定其存活率、虫重、化蛹率；使用凝胶渗透色谱法分析经过大麦虫幼虫肠道后塑料的分子量变化；通过Beta多样性、菌群组成、PICRUSt功能预测分析取食塑料后的大麦虫幼虫肠道微生物多样性及其与石油基塑料之间的关系。【结果】 取食聚苯乙烯和聚乙烯泡沫塑料25 d后，大麦虫幼虫存活率分别为（58.67±4.04）%和（62.5±5.27）%，取食麦麸组的大麦幼虫存活率为（84.5±0.87）%；取食塑料后大麦虫幼虫体重没有显著增加、不能化蛹；经大麦虫幼虫取食后，聚苯乙烯分子量降低，聚乙烯分子量升高；幼虫肠道内与塑料降解相关细菌相对丰度升高；取食聚苯乙烯后，幼虫肠道中芳香烃和烷烃降解基因携带菌得到富集。而取食聚乙烯后，幼虫肠道中芳香烃和烷烃降解基因携带菌并没有被富集。【结论】 大麦虫幼虫对聚苯乙烯和聚乙烯有一定的降解能力，但对聚乙烯的降解能力较差，这2种塑料均不能为大麦虫幼虫的生长发育提供足够的营养和能量。

[Objectives]  The consumption and breakdown of plastic waste by insects has been a popular research topic in recent years. We investigated the growth and development of Zophobas atratus larvae, changes in its gut microbiota and the molecular weight of plastics consumed by these larvae, in order to provide a foundation for further research on plastic degradation by this species. [Methods]  Larvae were fed either polystyrene or polyethylene foam, and their survival rate, weight and pupation rate were measured and compared. The molecular weight of plastics after passing through the guts of larvae was analyzed with gel permeation chromatography and the gut microbiota of larvae fed on plastics, and their relationship to pail-based plastics, were analyzed using Beta diversity, community composition and PICRUSt function prediction. [Results]  The survival rates of larvae fed on polystyrene or polyethylene foam were (58.67 ± 4.04)% and (62.50 ± 5.27)%, respectively, after 25 days, compared to (84.50 ± 0.87)% for the bran-fed control group. No significant increase in larval weight occurred in larvae that fed on plastics, nor did these larvae pupate. The molecular weight of polystyrene decreased after being digested by the larval gut, whereas that of polyethylene increased. The relative abundance of bacteria associated with plastic degradation increased in the guts of the larvae that fed of plastics. Larvae that fed on polystyrene had higher numbers of bacteria carrying aromatic hydrocarbon and alkane degradation genes in their gut whereas those that were fed on polyethylene did not. [Conclusion]  Polystyrene is more easily degraded than polyethylene by Z. atratus larvae. However, neither polystyrene nor polyethylene provide sufficient nutrition and energy for the normal growth and development of Z. atratus larvae.