**Figure 1.** **Metformin increases the adult and total mean lifespan in the male silkworm.** (**A**) Adult stage (n=27), (**B**) mean total lifespan (n=30), and (**C**) maximum lifespan (n=3) of unmated female silkworms administered metformin (Treatment) or deionized water (Control). (**D**) Adult stage (n=24), (**E**) mean total lifespan (n=54) and (**F**) maximum lifespan of unmated male silkworms administered metformin (Treatment) of deionized water (Control). Bars depict the mean + SEM, *P < 0.05, **P < 0.01, ***P < 0.001.