Evaluation of sex attractants for monitoring of Illiberis ulmivora Graeser (Lepidoptera: Zygaenidae: Procridinae): Height, distance, placement, climatic conditions

The phytophagous caterpillar Illiberis ulmivora is a serious pest of Ulmus glaucescens Franch (Ulmaceae, Ulmus). In order to test potent sex attractant, field trails of synthetic candidate attractants were conducted in China. In this study, baits with ternary blends, (2S)-butyl (7Z)-dodecenoate, (2S)-butyl (9Z)-tetradecenoate, and (2S)-butyl (5Z)-decenoate (8:4:1 ratio) resulted in a higher number of male moths capture than the rest of the baits that were offered. Traps positioned at a height of 1.2 m attracted more males than those installed at heights of 2.2 m and 3.2 m. The slope aspect, temperature and humility had a significant effect on the trap catches. More catches occurred in traps placed on semi-shady and semi-sunny slopes than those placed on sunny and shady slopes. The number of pheromones in the septa decreased with age. The residual amounts of pheromones in the lures combined with 2,6-di-tert - butyl-p-cresol (BHT) were higher than those in the control. However, there were no differences in the male captures between components and components combined with BHT during the first 8 d. These findings on monitoring and trap positions can be used to predict the occurrence and population dynamics of I. ulmivora, to develop ecological management of I. ulmivora.