Low-pressure from vacuum (V) and the insecticidal natural product ethyl formate (EF) were investigated in laboratory for controlling three insect species. When eggs of the Indianmeal moth, Plodia interpunctella, were exposed 4 hours to either V of 50 mm or two doses of EF mortalities did not exceed 88.00%. However, a combination of 50 mm Hg V with doses up to 10 gm/m³ EF was synergistic and resulted in complete mortality of all eggs in 4 hours. Probit analysis showed the LD99 at 50 mm Hg V was 8.48 gm/m³ EF for a 4-hr treatment. There were no significantly different between the untreated controls and a 50 mm Hg V alone for the Lesser grain borer, Rhyzopertha dominica eggs and Cottonwood borer, Plectrodera scalator larvae, but EF alone proved highly effective at killing these species ins four hours, and this effect may be improved with V. Ethyl formate shows excellent potential as a methyl bromide alternative for wood-boring insects.