Evaluation of Esterases and Phosphatases in three Strains of Callosobruchus chinensis and Rhyzopertha dominica treated with Plant Extracts and Synthetic Pyrethroids

Abstract

Stored grains have been attacked by different insect species for many years. To protect stored grains from insect attack, various control measures have been suggested. Current research was initiated in order to assess five plant extracts and three synthetic pyrethroids for their toxic and repellent efficiency and their effect on progeny inhibition of three strains of Callosobruchus chinensis and Rhyzopertha dominica. These treatments were also studied for their subsequent effects on the certain esterases and phosphatases enzymes of test insects. Azadirachta indica extract and deltamethrin were more effective. Significant mortality was obtained at the highest concentrations, after maximum exposure time. C. chinensis mortality with A. indica was 81.10, 69.23 and 86.82% in FSD, MLN and NNS strains respectively. 100% mortality was achieved with deltamethrin for all strains of C. chinensis. R. dominica mortality with A. indica was 65.19, 60.74 and 84.96% FSD, MLN and NNS strains respectively. Deltamethrin resulted in 95.56, 95.56 and 97.75% mortality of R. dominica Faisalabad, Multan and Nankana strain respectively. A. indica resulted in 79.99, 66.67 and 80.81% progeny inhibition of C. chinensis Faisalabad, Multan and Nankana strain respectively. 66.77, 60.32 and 70.40% reduction in progeny production of C. chinensis was achieved with deltamethrin, in Faisalabad, Multan and Nankana strain respectively. A. indica caused 90.22, 88.01 and 92.23% progeny inhibition of R. dominica in Faisalabad, Multan and Nankana strain respectively. Progeny inhibition of R. dominica was 90.46, 80.93 and 97.14% in Faisalabad, Multan and Nankana strain respectively with deltamethrin. In repellency bioassay, A. indica resulted in 93.33, 90.67 and 94.67% repellency in C. chinensis Faisalabad, Multan and Nankana strain, respectively. With deltamethrin repellency was 92.00, 90.67 and 97.33% in C. chinensis Faisalabad, Multan and Nankana strain respectively. Percentage repellency in in case of R. dominica was 94.67, 85.33 and 92.00 in Faisalabad, Multan and Nankana strain respectively, with A. indica. Repellency recorded with deltamethrin, in R. dominica was 90.67, 89.33 and 92.67% in Faisalabad, Multan and Nankana strain respectively. In case of enzymatic analysis, the inhibition of treatments was compared with the control. With A. indica treatment, in C. chinensis FSD strain, maximum AChE, ALP, ACP, α-CE and β-CE inhibition was 45.82, 29.98, 61.38, 43.65 and 50.81% respectively, 57.14, 39.98, 58.24, 41.04 and 50.58% respectively in MLN strain and 41.31, 28.87, 61.67, 45.24 and 50.32% respectively in NNS strain. Using M. azadirach, in C. chinensis FSD strain, maximum AChE, ALP, ACP, α-CE and β-CE inhibition was 55.82, 29.98, 53.37, 45.48 and 51.30% respectively, 63.81, 39.98, 52.67, 43.65 and 50.33% respectively in MLN strain and 51.98, 31.10, 52.84, 47.96 and 50.57% respectively in NNS strain. In pyrethroids, cypermethrin mostly resulted in high inhibition of enzymes. So, with cypermethrin maximum AChE, ALP, ACP, α-CE and β-CE inhibition was 19.14, 18.54, 47.65, 36.33 and 42.45% respectively, in C. chinensis FSD strain, 37.14, 21.09, 48.42, 36.33 and 39.12% respectively, in MLN strain and 14.96, 17.43, 46.95, 38.32 and 39.99% respectively in NNS strain. In R. dominica FSD strain, treated with A. indica maximum AChE, ALP, ACP, α-CE and β-CE inhibition was 39.42, 43.77, 47.79, 41.38 and 52.30% respectively, 37.57, 39.94, 47.31, 41.90 and 48.46% respectively in MLN strain and 40.41, 45.99, 51.59, 42.15 and 50.51% respectively in NNS strain. With M. azadirach treatment, in R. dominica FSD strain, maximum AChE, ALP, ACP, α-CE and β-CE inhibition was 40.83, 42.94, 45.71, 40.47 and 47.84% respectively, 39.70, 39.94, 44.13, 40.99 and 43.86% respectively in MLN strain and 41.83, 45.17, 51.59, 42.15 and 50.51% respectively in NNS strain. Using pyrethroids, enzymes inhibition was recorded maximum in R. dominica NNS strain with cypermethrin, which resulted in 34.03, 43.80, 49.45, 31.41 and 48.34% inhibition of AChE, ALP, ACP, α-CE and β-CE respectively as compared to the control treatment.