Abstract:Toxic effect of Lambda-cyhalothrin and essential oils of cardamom seeds of Elettaria cardamomum (L.), individually or in combination, on the larva, pupa and adult stages of confused flower beetle, Tribolium confusum, through the topical application were studied. The percentages of mortality of larval stage exposed to Lambda-cyhalothrin, The synergistic ratios for larvae, pupae and adults exposed to mixture 1 (0.03 µl / insect cardamom oil and different concentrations of pesticide ), were 2.01, 1.70 and 1.60, respectively, where as the synergistic ratios of larvae, pupae and adults exposed to mixture 2 ( 0.07 µl / insect cardamom oil and different concentrations of pesticide) were 2.61, 2.34 and 3.10, respectively. This indicates that a combination of cardamom seeds oil with different concentrations of the insecticide Lambda produced synergistic effects.

2-Hydroxy Chalcone and its derivatives (compounds 1and 2) were used in a toxicity test on the larvae and adults of confused flour beetle Tribolium confusum (Du Val). Mortality tests were done by applying different concentrations (0.01, 0.02 and 0.04 ppm) on 2-Hydroxy Chalcone and its derivatives which were exposed by topical application with 5 µL of each compound and the data were recorded after 24 h of treatments. The mortality % of [7-Hydroxy-9-(pyridine-4-yl)-6H-benzo[C]chromen-6-one] in (compound 2) were 26.6, 50 and 76.67% and 16.67, 36.67 and 63.3% and 13.3, 23.3 and 36.6 % to 3rd, 5th instar larvae and adults, respectively. While in [ 3-thinyl-1-(2-hydroxynaphthyl) -1-propene] (compound 1), the mortality % were 23.3, 40 and 66.6% and 13.3, 30 and 56.6% and 6.6, 16.6 and 26.6 % to 3rd, 5th instar larvae and adults, respectively. The results indicated that (comp.2) was the most toxic one and (comp.1) was the least toxic to confused flour beetle when applied singly. The calculated LC50 values to (compound 2) were 0.019, 0.028 and 0.074 ppm to 3rd, 5th instar larvae and adults, respectively. While to (compound 1), the LC50 values were 0.025, 0.034 and 0.106 ppm to 3rd, 5th instar larvae and adults, respectively. The order of toxicity of the chemical compounds was 2 > 1. These chemical compounds can be used to control confused flour beetle.

The effect of ethanolic extracts of Urtica dioica on mortality of the third Larval instar of Tribolium confusum, was studied using the Soxhlet and solvent extraction methods. Experiments at 30 ± 1°C and 70 ± 5% relative humidity. In laboratory conditions. The mortality data were recorded after 24, 48, and 72 hours. The mortality rate increased by an increase in concentrations (0.5, 1, 1.5, and 2.5 mg/ml), the highest mortality rate was 100% at 1.5 mg/ml, while the lowest percentage of mortality 73.33% was observed after 24 hrs of exposure at 0.5 mg/ml dose by Soxhlet extraction method, whereas the highest mortality rates 100% at 2.5 mg/ml concentration, while the lowest percentage of mortality 90% was observed after 24 hrs of exposure at 0.5 mg/ml dose by Solvent extraction methods. The results show that the plant extracts tested at different concentrations were toxic to the larvae of T. confusum, and both methods of extraction had nearly similar effects on larvae.

During this study the toxic effect of Actara and ginger oil of Zingiber officinale, individually or in combination, on the 3rd and 5th instar larvae of greater wax moth, Galleria mellonella L. was investigated. The percentages of mortality of 3rd and 5th instars larval stage exposed for Actara, at concentrations of 0.1, 0.15 and 0.2 µl/ larva, after 24 hours exposure were 17.50, 25.00 and 32.50 %, and 10.00, 12.50 and 17.50 respectively. The percentages of mortality of 3rd and 5th  instars larval stage exposed to mixture 1:1 of Actara insecticide and ginger oil at concentrations of  0.1, 0.15 and 0.2 µl/ larva were 26.60, 40.00 and 50.00% (for 3rd instar), and 20, 26.60 and 33.30% (for 5th instar) respectively, after exposure period of 24 hours. While the mortality of 3rd and 5th instars larval stage exposed to the mixing ratio 1:2 (Actara insecticide and ginger oil) of the same concentrations and same exposure period mentioned previously, were 36.60, 46.00 and 63.30 % (for 3rd instar), and 26.60, 36.60 and 46.60% (for 5th instar), respectively. Whereas in the mixing ratio 1:3(Actara insecticide and ginger oil) of same concentrations and same exposure period mentioned previously, the mortality (3rd and 5th instars larvae) were 53.30, 63.00 and 90.00 % (for 3rd instar), and 33.30, 46.60 and 63.00% (for 5th instar), respectively. The synergistic ratios for 3rd and 5th instars larval stage exposed to mixtures 1:1, 1:2 and 1:3 (different concentrations of Actara insecticide and ginger oil), were 1.25, 1.6 and 2.4 (for 3rd instar), and 1.88, 3.50 and 4.01 (for 5th instar), respectively, after 24 hours of exposure.  This indicates that a combination of different concentrations of the Actara insecticide with ginger oil produced synergistic effect.