Joint action of spinosad and sweet almond oil mixture against the saw toothed grain beetle, oryzaephilus surinamensis (l. )‎

Abstract EN

Bioassay tests were conducted to determine the combined action of spinosad and sweet almond oil against the adults of Oryzaephilus surinamensis (Coleoptea, Silvanidae), at 28 ±2°C and 65±5% RH and 21 days exposure period.

The tests were applied at different concentrations, 6 for spinosad, 5 for sweet almond oil and 4 for their mixtures.

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

The mortality of O.

surinamensis adults reached 98.0% using a concentration of 1 × 10^-3 % (w / w) of spinosad on the day 21 of the exposure.

Data also revealed that, the spinosad pesticide was very toxic for the treated insect, and it gave LC₅₀ of 8.6×10^-4 % (w/w), for the adults of O.

surinamensis (after 7 days exposure period).

The mortality effect of sweet almond oil on O.

surinamensis adults reached 98.0% at concentration of 5% (v/w) on the day 21 of exposure.

Data showed that, the sweet almond oil gave LC₅₀ of 4.521% (v/w), for the adults of O.

surinamensis (after 7 days exposure period).

The efficacy of the two tested compounds as a mixture at the various concentrations indicated that spinosad and sweet almond oil mixture of LC₂₀ spinosad + LC₂₀ sweet almond was the most effective compared with other mixtures against O.

surinamensis on the basis of co-toxicity factor.