Detection of hidden insect Sitophilus oryzae in wheat by low-field nuclear magnetic resonance

Abstract

Insects, either adults or larvae, living inside grains are difficlut to detect but can cause enormous loss of grain. Therefore, we explored the use of low-field nuclear magnetic resonance (LF-NMR) techniques to detect Sitophilus oryzae hidden inside wheat. Significant difference in transverse relaxation times (T2/ms) and the T2 components proportion (P2/%) was observed between wheat and S. oryzae at its four different growth stages (small larvae, large larve stage, pupal stage and adult stage). The transverse relaxation signals on the infested wheat kernels varied with S. oryzae developmental stages. LF-NMR image of uninfested wheat were very different than infested wheat with the hidden insects at its four growth stages. Therefore, LF-NMR, as a novel non-destructive method, could be used to detect insects hidden in grains to take necessary management against pest damage to grains during storage.

Keywords

• rice weevil (sitophilus oryzae)
• grain storage
• transverse relaxation signal
• infested wheat
• low field magnetic resonance imaging