Background:
The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)
is one of the world’s most serious stored grain insect pests. A method of early and rapid identification
of red flour beetle in stored products is urgently required to improve control options. Specific
chemical signals identified as Volatile Organic Compounds (VOCs) that are released by the
beetle can serve as biomarkers.
Methods:
The Headspace Solid Phase Microextraction (HS-SPME) technique and the analytical
conditions with GC and GCMS were optimised and validated for the determination of VOCs released
from T. castaneum.
Results:
The 50/30 μm DVB/CAR/PDMS SPME fibre was selected for extraction of VOCs from
T. castaneum. The efficiency of extraction of VOCs was significantly affected by the extraction time,
temperature, insect density and type of SPME fibre. Twenty-three VOCs were extracted from insects
in 4 mL flask at 35 ± 1°C for four hours of extraction and separated and identified with gas
chromatography-mass spectroscopy. The major VOCs or chemical signals from T. castaneum were
1-pentadecene, p-Benzoquinone, 2-methyl- and p-Benzoquinone, 2-ethyl.
Conclusion:
This study showed that HS-SPME GC technology is a robust and cost-effective method
for extraction and identification of the unique VOCs produced by T. castaneum. Therefore, this technology
could lead to a new approach in the timely detection of T. castaneum and its subsequent
treatment.