Abstract Brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) is an economically important insect pest of rice crop worldwide including Pakistan. The use of chemicals insecticides to control the BPH population has been considered an effective strategy. However, long-term and intensive use of insecticides has resulted in resistance against this pest. In this study, six recommended insecticides were tested against BPH over the period of 2015-2019 to determine the susceptibility level. From 2015-19, susceptibility of BPH was reduced to all tested insecticides. Increasing trend of LC50 values was recorded in fipronil (18.23-35.11 mg/L), imidacloprid (64.22-128.8 mg/L), buprofezin (185.01-315.0 mg/L), chlorantranilipyrole (199.2-263.3 mg/L), pymetrozine (248.2-315.5 mg/L), and nitenpyram (21.07-34.3 mg/L) respectively from 2015 to 2019. Correlation coefficient values indicated a significant relation (P < 0.05) between fipronil, imidacloprid, and buprofezin. The study will be helpful for resistance management strategies to prevent the resistance development in BPH against insecticides.
Resumen El saltamontes marrón (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), es una plaga de insectos económicamente importante del cultivo de arroz en todo el mundo, incluido Pakistán. El uso de insecticidas químicos para controlarla ha constituido una estrategia eficaz; sin embargo, utilizarlos de forma prolongada e intensiva ha ocasionado que la plaga se vuelva resistente a dichos pesticidas. En este estudio se probaron seis insecticidas recomendados contra la BPH durante el periodo 2015-2019 para determinar el nivel de susceptibilidad. De 2015 a 2019, la susceptibilidad a la BPH se redujo a todos los insecticidas probados. Se registró una tendencia creciente de los valores de LC50 en fipronil (18.23-35.11 mg/l), imidacloprid (64.22-128.8 mg/l), buprofezina (185.01-315.0 mg/l), clorantranilipirol (199.2-263.3 mg/l), pimetrozina (248.2-315.5 mg/l) y nitenpiram (21.07-34.3 mg/l) respectivamente de 2015 a 2019. Los valores del coeficiente de correlación indicaron una relación significativa (P < 0.05) entre fipronil, imidacloprid y buprofezin. El estudio será útil tanto para llevar a cabo estrategias de manejo de la resistencia como para prevenir el desarrollo dicha resistencia de la BPH hacia los insecticidas.