Semanotus

Abstract: Research over the past decade has shown that attractant pheromones used by cerambycid beetles are often highly conserved, with the same compound being used as a pheromone component by multiple related species, even among species on different continents which have been separated for millions of years. We describe how this conservation of structures can be exploited to identify possible pheromone components for Asian target species with a high risk of invading North America. Thus, collection and analysis of volatiles from five North American species, Semanotus amethystinus (LeConte), Semanotus ligneus (F.), Semanotus litigiosus (Casey), Callidium antennatum hesperum Casey, and Callidium pseudotsugae Fisher, showed that males of the two Callidium species sex-specifically produced 3-hydroxyhexan-2-one, a previously known cerambycid pheromone component, along with a novel natural product, 1-(1H-pyrrol-2-yl)-1,2-propanedione (henceforth pyrrole). In contrast, males of the three Semanotus species produced only the pyrrole. In field bioassays, both sexes of C. antennatum hesperum were significantly attracted to the blend of the two compounds, and S. amethystinus were equally attracted to the pyrrole alone, or the blend of the two compounds. Even before completing field bioassays with these species in California, field testing of the two compounds in Japan and China had revealed that several related target species, including the invasive Callidiellum rufipenne (Motschulsky), Callidiellum villosulum (Fairmaire), and Semanotus bifasciatus (Motschulsky), were attracted to one or both compounds (data reported elsewhere), providing proof of concept of the “pheromone identification by proxy” strategy.

Abstract: During field trials of the two known cerambycid beetle pheromone components 3-hydroxyhexan-2-one and 1-(1 H -pyrrol-2-yl)-1,2-propanedione (henceforth “pyrrole”) in Guangxi and Anhui provinces in China, four species in the subfamily Cerambycinae were attracted to lures containing one of the two components, or the blend of the two. Thus, the invasive species Callidiellum villosulum (Fairmaire) (tribe Callidiini) and a second species, Xylotrechus buqueti (Castelnau & Gory) (tribe Clytini), were specifically attracted to the blend of 3-hydroxyhexan-2-one and the pyrrole. In contrast, Allotreus asiaticus (Schwarzer) (tribe Phoracanthini) and Semanotus bifasciatus Motschulsky (tribe Callidiini) were specifically attracted to the pyrrole as a single component. In most cases, both males and females were attracted, indicating that the compounds are likely to be aggregation-sex pheromones. The results indicate that the two compounds are conserved as pheromone components among species within at least three tribes within the subfamily Cerambycinae. For practical purposes, the attractants could find immediate use in surveillance programs aimed at detecting incursions of these species into new areas of the world, including the United States.

Abstract: In order to found new carriers of pine wood nematode (PWN), Bursaphelenchus xylophilus, beetles were collected from pine wilt disease-affected areas in six provinces in China. A total of 8830 beetles of 29 species was collected and examined to determine whether they were PWN carriers. Eight species were identified as carriers. Results included the first worldwide report of Monochamus nigromaculatus, Semanotus sinoauster, and Uraecha angusta being carriers of PWN, and the first report from China of Arhopalus rusticus carrying PWN. Monochamus alternatus was commonly collected in all six provinces and was the dominant species in four inland affected areas and A. rusticus was dominant in two coastal affected areas. The species varied between different neighboring regions in the same province. The distribution of the same species varied considerably over different regions.