In this study, the toxicity of Cherry laurel (Prunus laurocerasus L. (Rosaceae)) leaf and seed extracts at doses of 10, 15, and 20 mL/L against Brown Marmorated Stink Bug (Halyomorpha halys Stål (Hemiptera: Pentatomidae)) adults and nymphs (N1, N2, N3, N4, N5) at 24., 48., 72., and 96. hours were investigated under laboratory conditions. All experiments were performed separately for five nymphal stages and adults and repeated three times for each dose. Pure water + ethanol was used as a negative control, and the chemical Nimbecidine® (10%) was used as a positive control. At the 96 hours of treatment, Prunus laurocerasus leaf extracts caused mortality between 21.5% and 100%, while the seed extract caused mortality between 30.3% and 100%. The highest mortality rate occurred in the N1 and N2 instar nymphs (100%) at the 20 mL/L dose, and the lowest mortality rate occurred in the adult stage (21.5%) at the 10 mL/L dose. The productivity rates of seed extracts were higher than those of leaf extracts. In all treatments, mortality rates increased with increasing dose and time. In conclusion, the results showed that Prunus laurocerasus leaf and seed extracts had a highly toxic effect against five nymphal stages and adult H. halys. The most toxic LD50 values in leaf extract were kept as 0.45 and 3.64 mL/L for N1 stage nymphs and juveniles, while the lowest LD90 values were determined as 4.54 and 6.64 mL/L for N5 instar nymphs and adults, respectively. The seed extract yielded the lowest LD50 values of 0.29 and 1.84 mL/L for N1 instar nymphs and adults, and the lowest LD90 values of 2.89 and 3.15 mL/L for N5 instar nymphs and adults, respectively. The results indicate that leaf and seed extracts of P. laurocerasus have excellent potential for the control of Halyomorppha halys.
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