Research during the 1980s showed that male Xylotrechus pyrrhoderus Bates (Coleoptera: Cerambycidae), a vineyard pest, produce (2S,3S)-2,3-octanediol and (S)-2-hydroxyoctan-3-one as possible pheromone components, but to our knowledge, field tests were not carried out.We confirmed that at least female X. pyrrhoderus were attracted by a 1:1 blend of these two compounds in field trials in Japan. Furthermore, more than 200 males and females of the congener Xylotrechus rufilius Bates were attracted by racemic 2-hydroxyoctan-3-one, and inhibited by syn-2,3-octanediol. Adult X. rufilius recently were intercepted in a shipment from China entering Baltimore, Maryland, raising concerns that this polyphagous species could establish in North America. Our results suggest that traps baited with 2-hydroxyoctan-3-one would be a valuable tool to assess whether X. rufilius has indeed become established, and to monitor for future introductions of X. rufilius.