Evaporation Rates of a Five-Component Attractant for the Rose Chafer (Coleoptera: Scarabaeidae)

The attractant developed for the rose chafer, Macrodactylus subspinosus (F.), is composed of pentanoic acid (valeric acid), hexanoic acid, octyl butanoate (octyl butyrate), trans-2-nonen-1-ol and alpha-ionone. Studies were conducted to determine evaporation rates of the five components and evaluate the ability of the attractants to lure beetles at various quantities of attractant over a 3 wk period of adult activity. Pentanoic acid (valeric acid), the compound with the lowest boiling point of the five compounds, was found to decrease from 26% to 7% by gas chromatographic studies. Alpha-ionone, the component with the highest boiling point of the five compounds, increased from 15% to 26%, while the other three compounds increased by 1% to 5%. Field studies demonstrated that lures baited with 5 mL of attractant provided the best results.