Effects of nitrogen on bionomics and food consumption of Cabera pusaria (Lepidoptera: Geometridae)

Abstract

Birches, Betula pendula Roth, grown in pots were fertilized with ammonium nitrate (NH4NO3) in the amounts of 0 g, 0.5 g, 1 g and 1.5 g per plant four times per season on moist soil surface with subsequent gradual dissolution by watering. Cabera pusaria caterpillars from laboratory were fed on leaves with different content of nitrogen (19.2-47.4 mg×g -1). The excessive content of nitrogen in food appeared to be a stress factor as it increased mortality and development time of the caterpillars, decreased food consumption and weight of larvae and pupae, and caused anomalies at pupation. This is as expected for a summer-feeding caterpillar feeding on foliage with seasonally decreasing concentration of nitrogen. © Entomologica Fennica.