A new defoliating threat to eucalyptus plantations: biology and foliar consumption of <i>Physocleora dukinfeldia</i> (Lepidoptera: Geometridae).

Abstract

The defoliator <i>Physocleora dukinfeldia</i> Schaus 1897 (Lepidoptera: Geometridae) was recently reported attacking <i>Eucalyptus urograndis</i> (Myrtaceae) plantations in Brazil, raising concerns about its potential impact on commercial forestry. In this context, early characterization of pest biology plays a critical role in understanding host-use patterns and forecasting potential impacts on forest ecosystems. This study aimed to characterize the biology and foliar consumption of <i>P. dukinfeldia</i> on <i>E. urograndis</i> and its native host, <i>Schinus terebinthifolia</i> (Anacardiaceae), by recording molting, mortality, pupation, and emergence of imago, measuring larval head capsule width, pupal weight, and size, and calculating stage duration and viability under controlled conditions. The insect completed its life cycle on both host plants, with significantly longer development time and reduced pupal viability observed on <i>E. urograndis</i>. Although larval survival was low on both host species, nearly one-third of the individuals successfully reached adulthood. No significant differences in leaf consumption were detected between the two eucalyptus species evaluated in this study. These findings indicate that <i>P. dukinfeldia</i> has the biological capacity to adapt to eucalyptus and should be closely monitored in forest production areas. This is the first report to detail the life cycle and feeding behavior of this species on eucalyptus, providing critical baseline information for future pest management strategies.