LAUSR

ABSTRACT Eucryptorrhynchus brandti Harold is a trunk-boring pest of tree-of-heaven Ailanthus altissima (Mill.) Swingle in China, and is being studied in quarantine in the United States as a potential biological control agent against the tree-of-heaven. In this study, oviposition behaviour of E. brandti was observed with a macro lens camera to record and describe the successive stages of oviposition. Oviposition of E. brandti consists of nine main sequential steps, sometimes followed by grooming: wide-area search, site location, oviposition cavity excavation, excitation, turning, locating the oviposition cavity, egg deposition, egg concealment and resting. Gravid females mainly lay eggs by day, with no obvious oviposition observed by night. Excavation is the longest stage of the process, and the probability of egg laying increases if excavation time exceeds 28 min. There is no obvious preference in the post-drilling turning direction (left or right) during oviposition. This is the first complete description of oviposition behaviour of E. brandti. The positive correlation between time spent excavation and probability of oviposition means that excavation time can be used to predict the success or failure of an egg-laying female.