تجزیه و تحلیل مدل مکانیکی پویایی جمعیت شته برگ برنج، Rhopalosiphum padi L. (Hemiptera: Aphididae) در ذرت (Zea mays L.)

Maize (Zea mays L.) is one of the most important cereals worldwide. Among the biotic factors, the bird cherry-oat aphid, Rhopalosiphum padi L. (Hemiptera: Aphididae) is one of the most important biotic constraints for maize production in IRAN. A 1-year field study was conducted to generate data on seasonal abundance patterns of different stage of the bird cherry-oat aphid, R. padi and to develop a mechanistic model based on cumulative population size. A nonlinear regression model, was fitted well to different stages, nymphs (r2=0.96), adult (r2=0.93), and winged adult (r2=0.95), data sets collected during 2022. The size and time of the peak, the cumulative aphid density, and the birth and death rates were estimated for each stage (Nymphs, Adult and Winged adult) of R. padi population. The parameters of the regression model are the predicted peak size, Nmax, (for nymphs, adults, and winged adults were 113, 7.37 and 1.24 per plant respectively) the predicted time of peak, tmax, (for nymphs, adults, and winged adults were 282, 281.5 and 283.2 days respectively) and an approximate per capita birth rate, b, (for nymphs, adults, and winged adults were 0.093, 0.226 and 0.087 respectively), all of which are of interest in practical application and shown to be accurate. The nonlinear regression model fits R. padi data very well, which provides a mechanism for the statistical analysis of aphid count data. Consequently, effective control strategies for this aphid can be developed to avoid damage to corn. This successful fitting also suggests investigations using the model to describe population growth curves in different conditions.