Analysis of the Population Dynamics of Whitefly (Bemisia tabaci [Hemiptera: Aleyrodidae]) Under Greenhouse Conditions

Abstract

Whiteflies (Bemisia tabaci) represent an insect pest in horticulture. It serves as a vector for transmitting phytopathogens that inhibit the correct development of plants, affecting crop performance. In this research, whitefly population model was proposed to provide a tool that predicts the pest spread within a crop under greenhouse conditions. The analysis, calibration, and validation of the models, based on logistic functions, were implemented for the three stages (egg, nymph, and adult) of the life cycle of this organism. Temperature (°C), relative humidity (%), initial population (number/cm2), and Growing Degree-Day (GDD) were considered as input variables to describe each development stage. The statistical analysis for the model validation included the coefficient of determination (R2), the percentage standard error of prediction (%SEP), the average relative variance (AVR), and the efficiency coefficient (E). The first period for calibration consisted of 43 d (204.3 GDD), and the second period for validation consisted of 36 d (171.1 GDD). The model efficiently predicts the population growth for the egg, nymph, and adult stages since the values of R2 were 0.9856, 0.9918, and 0.9436, and the values of %SEP were 12.4, 11.9, and 75.1% for the egg, nymph, and adult stages, respectively. Moreover, the validation model obtained an R2 of 0.9287 for the egg stage, 0.9645 for the nymph stage, and 0.9884 for the adult stage. Meanwhile, the values of %SEP were 10.38, 16.89, and 32.59% for the egg, nymph, and adult stages, respectively. In both cases, the values suggest an adequate fit for the model.