Essential oils have good potency to be used as alternative for controlling stored product insects, so our dependency on synthetic fumigants can be avoided since synthetic fumigant like phosphine can cause resistance to stored product insects. The objectives of this research were to: (1) producing nanoemulsion and nanopowder of mint oil, (2) producing nanoformulation, (3) find out the best nanoformulation, (4) collecting stored product insects from food and feed warehouses in the Provinve of West Sumatera, South Sumatera, and North Sulawesi, and testing their resistance against phosphine in the laboratory, (5) producing database of phosphine resistant strains of stored product insects in Indonesia. The results showed that nanoemulsion of mint oil can be fomulated and stabilized with 10% of mint oil concentration by adding Tween and glycerol as emulsifier in 1:1 composition. Particle size of nanoemulsion formed was 98.57 nm with the value of
PolyDispersion Index (PDI) and zeta potensial -16.3 and 0.510 respectively. Nanopowder of mint oil was formed through the process of spray drying with maltodextrin 40% as encapsulate. Nanopowder produced was in form of white powder with a rounded surface shape, experiencing shrinkage, and the shape tends to be not uniform. Nanoemulsion of mint oil formulated as tablets showing higher effectiveness compared to tablet formulation of n-hexane fraction of crude mint oil at the same level of concentration. Stored product insects collected from food and feed waerhouses in the Province of West Sumatera, South Sumatera, and North Sulawesi showed varied level of resistance (RF) against phosphine:
Tribolium castaneum 0.83 – 23.30 times and Rhyzopertha dominica 0.83 – 52.65 times.