Abstract: During the forestry pest investigation in Luzhou city, Sichuan province, a rare nesting behavior of mud wasp (Apodynerys formosenes) was firstly discovered, which overturned the previous record and cognition of nest-building behavior of mud wasps. In this nesting behavior, the material used for the nest building was not the common soil, but the resin was secreted from the wounded pines. A single resin nest was cylindrical in shape, with an inner diameter of 10 mm, an outer diameter of 16 mm and a length of about 15 mm. It was formed with many little resin balls processed by mud wasp, and the diameter of the resin balls is 0.5-1 mm. The nest was delicate in appearance, ingenious in structure, milky white and semitransparent. Moreover, there was a mud wasp which was about to mature in the resin nest, which showed that the function of the resin nest was completely consistent with that of the common mud wasps. The newly discovery resin nesting behavior of the mud wasps, fully reflected the survival wisdom of Apodynerys formosenes and the ingenious utilization of environmental resources, and greatly enriched the cognition of the living habits of this type of insects.