Effects of nitrogen on the selection of food by Phyllobius arborator (Herbst)

entiated inputs of nitrogen after the repeated application of ammonium nitrate into soil was monitored at Phyllobius arborator (Herbst) under field (polythene greenhouse) and laboratory (Climacell) conditions. In birch leaves, the content of nitrogen increased. The diameter and height increment was stimulated by the application of 0.5-1 g, higher doses induced stress and the fall of increment. According to the frequency of feeding marks on leaves and food consumption by weevils of the genus Phyllobius in a polythene greenhouse, birch with the higher content of nitrogen was preferred. In laboratory rearing, females showed higher food requirements. In short-term rearing, differentiation did not occur in the amount of consumed food in males and females depending on the nitrogen content.