The toxicity of four monoterpenes present in loblolly (Pinus taeda L.) and shortleaf (P. echinata Mill.) pine to Dendroctonus frontalis Zimmermann and Ips calligraphus (Germar) (Coleoptera: Scolytidae) was examined in the laboratory. The descending order of toxicity of the monoterpenes to D. frontalis was: limonene, β - pinene, α - pinene, camphene. No clearcut ordering in toxicity to I. calligraphus was observed.