Bioactivity of Three Plant Essential Oils against Red Flour Beetle (Tribolium castaneum) (Coleoptera: Tenebrionidae)

The red flour beetle (Tribolium castaneum) is a cosmopolitan stored product pest causing serious infestations to raw stored grains, cereal processing units, warehouses, retail stores and home granaries. In this study, we evaluated the effects of three essential oils against red flour beetle. These essential oils were extracted from clove (Syzygium aromaticum), olive (Olea vera) and kalvanji (Nigella sativa), and were tested at 2, 4, 6, 8 and 10% in contrast to a control treatment containing only acetone as a formulation. The mortality data was recorded after 24, 48 and 72 hours of application of essential oils. The olive oil was found to be the most effective against the grubs of red flour beetle followed by kalvanji and clove oil, having the LT50 values of 67.17h, 75.71h and 88.93h, respectively. The clove oil was found to be the most effective against the adults of red flour beetle followed by kalvanji and olive ion having the LT50 values of 81.11h, 96.81h and 105.33h respectively. The lowest LC50 of 9.17% against the grubs of red flour beetle was recorded with clove oil followed by the olive and kalvanji oil where the LC50 values were 9.34% and 14.27% respectively. Against the adults of red flour beetle, the lowest LC50 of 9.65% was recorded with clove oil followed by kalvanji (11.39%) and olive soil (16.33%). The maximum repellent effect was recorded with kalvanji oil (48.3%) followed by olive (47.5%) and clove oil (46%) against red flour beetle.