Maize hybrid and nutrient specific evaluation of the population dynamics and damage of the western corn rootworm (Diabrotica Virgifera Virgifera LeConte) in a long-term field experiment

Agricultural production is threatened by different invasive species, as their damage results in a serious loss of income. The aim of the research was the assessment of the swarming dynamics and damage of the western corn rootworm (WCR) adults and larvae. The experiment was carried out in monoculture fertilization long-term experiments and three maize hybrids compared for their reaction against WCR adult and larval damage under non-infested plots at different nitrogen levels. Differences among the hybrids have a lower effect on the damage of corn rootworm adults and larvae than the amount of applied nitrogen. The phosphorus-potassium are optimal levels, while nitrogen ranges from 0 to 300 kg and no nutrient supply took place in the control plots for 30 years. The number of adults located and feeding on the styles of the female flower recorded and the damage caused on the roots by larvae ranked on a modified Iowa scale. Nitrogen fertilization resulted in a change in the silking time. The lowest root damage observed in the case of the high nutrient treatment with an Iowa value of 3.18. The coincidence of the nourishment of adults and the egg-laying time with silking is a potential threat in terms of fertility. Based on the results, it found that the extent of root damage can be reduced through the optimal selection of the time and dose of nutrient supply, primarily that of nitrogen. In general, both larvae and adults can cause severe yield loss, but the method of control against them is different. The coincidence of the nourishment of adults and the egg-laying time with silking is a potential threat in terms of fertility.