The concentrations of copper (Cu), iron (Fe), nickel (Ni), and cadmium (Cd) were analyzed in the pupae ofBupalus piniarius(L.) andPanolis flammea(Denis and Schiffermüller) reared on needles collected from the same sites with different heavy-metal levels. Metal analysis on an individual basis revealed specific differences between the two common defoliators of the Scots pine (Pinus sylvestrisL.). The highest heavy-metal concentrations inB. piniarius(Cu 137, Fe 83, Ni 2.1, Cd 0.9 μgg−1)andP. flammea(Cu 89, Fe 59, Ni 5.3, Cd 2.9 μgg−1)were recorded in those reared on needles from the vicinity of the emission source in Finland. The decreasing trend of the log-transformed metal concentrations followed a linear regression model with increasing distance from the factories. The ratio between the concentration of copper and iron in the insects and that in the needles was proportionally lower in heavily polluted areas. Cadmium bioaccumulation was observed inP. flammeabut not inB. piniarius.