Effect of diethyl maleate on the toxicity of garlic (Allium sativum L.) extract to Tribolium castaneum Herbst under laboratory conditions

Abstract

The synergistic effect of diethyl maleate (DEM) on the toxicity of garlic (Allium sativum L.) extract against the stored-product pest, Tribolium castaneum Herbst was studied. DEM [one part] combined with acetone [two parts], was applied on T. castaneum adults. Five concentrations of garlic extract were tested. Three replicates and 30 adult insects/replicate/each concentration, were used. LC₅₀ values after 24 and 48 h of exposure were 127.90 and 90.8 μL/L air, respectively. Combination of the garlic extract with the synergist DEM after 24 and 48 h of exposure decreased the corresponding LC₅₀ values to 83.2 and 57.3 μL/L air, respectively. These results revealed that DEM can considerably improve the potency of garlic extract and maybe applied successfully in the stored-product pest control programmes.

Keywords:

• Allium sativum L
• diethyl maleate
• synergism
• Tribolium castaneum Herbst