Efficacy of some plant oils against the rice weevil, Sitophilus oryzae (L.)‎ and the red flour beetle, Tribolium castaneum (Herbst)‎

Abstract EN

Laboratory bioassay tests were conducted to determine the efficacy of geranium, coriander and cumin oils against the adults of Sitophilus oryzae (L.) and Tribolium castaneum (Coleroptera), at 30 and 20 ±1°C.

The results indicated that the mortality of tested insects increased with increasing in concentration, exposure period and temperature.

The complete mortality of S.

oryzae adults was obtained at conc.

1.5 % (v/w) for the three tested oils, after 14 days exposure period at 30°C.

Data also revealed that, the geranium oil was the most toxic for the studied insects at the two tested temperatures, and it gave LC50 of 0.49 , 1.72% at 30ºC and 0.88 , 1.89% at 20ºC for the adults of S.

oryzae and T.

castaneum (after 3 days exposure period), respectively.

The adults of S.

oryzae were more sensitive to tested plant oils than the adults of T.

castaneum.

It can be concluded that geranium, coriander and cumin oils have a toxic activity against the two stored-product insects, S.

oryzae and T.

castaneum.