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The longhorned beetle Rosalia batesi Harold (Coleoptera; Cerambycidae) is endemic to Japan, where its range extends from Hokkaido to Kyushu. The colorful adults are well-known to entomologists and collectors worldwide. It is a hardwood-boring species with larvae that develop in dead broad-leaf trees. In laboratory bioassays, females were attracted to males, which suggested that males produce a sex pheromone. The congeneric species R. alpina is native to Europe, and another congener, R. funebris, is distributed in North America. The pheromone components produced by males of these species had been previously identified as two compounds from different biosynthetic pathways. In the present study, volatiles were collected from beetles of both sexes, and the analyses of the resulting extracts revealed a single male-specific compound, which was identified as 3,5-dimethyl-6-(1-methylbutyl)-pyran-2-one; this is the same compound as the pheromone of the European R. alpina. This alkylated pyrone structure is, so far, unique among known cerambycid pheromones. In field bioassays with traps baited with the racemic synthetic pheromone, significant numbers of both sexes of R. batesi were attracted in an approximately equal ratio, indicating that the compound is an aggregation-sex pheromone rather than a sex pheromone.

Invasive Anoplophora glabripennis recently became established in Japan and has caused heavy damage to several street-tree species. Overseas, A. glabripennis infests trees of the genera Acer and Populus as common host plants, and Malus, Pyrus, and Prunus (Rosaceae), including apple, pear, and plum trees; it therefore poses a potential risk to the production of economically valuable fruits in Japan. Fruit farms in areas already invaded by A. glabripennis are now threatened with tree infestation. We aimed to determine the potential damage to major fruit species in Japan. In the laboratory, we determined if the adult beetle is attracted to the odor of each of these tree species' branches; two confirmed host plant species and five Rosaceae fruit species, as well as its feeding preferences among branches of one host plant and the five fruit trees and its oviposition preferences among them. Among the fruit species, cherry branch had the highest rate of odor orientation by males. The feeding-preference assay showed that, besides the host plant, Japanese pear was the most consumed among the fruit trees. The potential risk of A. glabripennis laying eggs on fruit-tree branches was high for Japanese pear and above zero for plum, apple, and cherry branches., (© 2024. The Author(s).)