Identifying the maternal origin of dispersed seeds is a challenging task because it is impossible to directly track seed movement once an animal has ingested them. However, recent development of molecular techniques allows us to identify the maternal origin of dispersed seeds in natural plant populations. Here we analyzed the maternal origin of Myrica rubra seeds found in the feces of Yakushima macaques. We detected a high level of diversity among the dispersed seeds, with an average of 3.0 maternal origins (range 1-9) in each feces. The average dispersal distance was 270.0 m (range 20.4-634.0 m) and the average of distance between maternal trees of dispersed seeds in the same feces was 161.5 m (range 0-573.9 m). These results suggest that seed dispersal by macaques plays an important role in maintaining the genetic diversity of Myrica rubra populations.

We developed 13 microsatellite markers from a genomic library enriched for dinucleotide (CT) repeats in a dioecious evergreen tree, Myrica rubra . We screened loci from 32 adult trees. The number of alleles ranged from two to 14, and the expected heterozygosity ranged from 0.324 to 0.884. The total paternity exclusionary power where the mother was known equalled 0.99965. These loci are of clear value in studying mating system and parentage analysis of this species.

We investigated pre-dispersal seed predation by insects in a bayberry Myrica rubra Sieb. et Zucc. (Myricaceae) on Yakushima Island, Japan. To clarify the patterns of seed fate and predation, all fruit that fell into seed traps were collected to allow any insect larvae within the fruit to emerge, and the fruit were finally dissected to determine whether or not they had been attacked by insect predators. Two lepidopteran species, Thiotricha pancratiastis (Meyrick) (Gelechiidae) and Neoblastobasis spiniharpella Kuznetzov & Sinev (Blastobasidae), emerged from the fruits. Thiotricha pancratiastis is the major seed predator of M. rubra, attacking the fruits intensively during the primary stage of fruit development. Thiotricha pancratiastis had been known as a foliage feeder (leaf miner) of M. rubra, but we revealed that the insect is also an important seed predator of the bayberry.