Evaluating the interaction between gamma radiation and Carum copticum essential oil for the control of Tribolium confusum (Coleoptera: Tenebrionidae)

Abstract

The combined effect of gamma radiation and Carum copticum C. B. Clarke essential oil were determined for the management of Tribolium confusum Du Val larvae and adults. Experiments were carried out at 27 ± 1 ºC and 65 ± 5% R. H. under dark condition and three steps were designed: (A) Application of gamma radiation and essential oil at the same time. (B) Irradiation followed by essential oil. (C) Essential oil followed by irradiation. Radiation doses of 100 to 500 Gy were applied in combination with 5.97, 7.52 and 10.47 μl/l air of essential oil for the adults and 1.91, 4.08 and 12.02 μl/l for the larvae. The result showed that the combination of gamma radiation with C. copticum oil increased larval and adult mortality compared with the control, so that, the interaction of 500 Gy with 10.47 μl/l air for adults and 12.02 μl/l air for larvae caused 100% mortality in 13 and 8 days, respectively; although 100% of the larvae and adults mortality at 500 Gy alone caused within 22 days. It was revealed that the combination of irradiation and essential oils could be used as an effective control method and a good alternative to fumigants.

Keywords

• carum copticum
• combined effect
• essential oil
• gamma radiation
• synergistic effect