Summary:The chestnut gall wasp Dryocosmus kuriphilus is a global pest of chestnut (Castanea). Established as a pest in the mid 20th century in Japan, Korea and the USA, this species has now reached Europe. Successful deployment of a biocontrol agent, Torymus sinensis, in Japan has led to its early release in Italy. Here we provide the first overview of the natural enemies associated with D. kuriphilus in its native and invaded ranges, and discuss general patterns in community development. We then use what is known about European oak gall wasp communities to predict possible future developments for D. kuriphilus, and possible interactions between parasitoid communities attacking hosts on chestnut and oaks.

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The parasitoid wasps Torymus sinensis (Ts) and three strains of T. beneficus (early-spring strain: TbE; late-spring strain: TbL; autumn strain: TbA) are respectively introduced and indigenous natural enemies of the chestnut gall wasp Dryocosmus kuriphilus, an invasive chestnut pest. In this study, the genetic relationships among Ts and three strains of Tb from Japan, China and Korea were investigated by sequencing a portion of the mitochondrial cytochrome oxidase subunit I (COI) gene. Three distinct groups were recognized in a constructed phylogenetic tree, the first group further consists of three subgroups. Ts belongs to two subgroups, whereas TbL belongs to the remaining subgroup. TbE and TbA belong to the second group, indicating that TbL is genetically more closely related to Ts a different species than to TbE and TbA strains considered the same species. This requires a reconsideration, especially for TbL, of their taxonomical treatment. The third group consisted of an indigenous Torymus parasitoid that we were unable to identify morphologically, indicating that an unknown Torymus parasitoid that is both genetically and morphologically different from the Ts and the Tb strains exploits D. kuriphilus in Japan.

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Mass rearing techniques are essential elements in developing a reliable and economic biological control method for Orius sauteri, a promising indigenous Orius species for biological control of Thrips palmi in greenhouses. Orius sauteri was reared on Ephestia kuehniella eggs and life history parameters and the minimum number of E. kuehniella eggs for rearing O. sauteri individuals were measured at 25°C and L16:D8. Developmental time during the nymphal stages was about 14 days for both sexes. Total fecundity and female longevity were 103.9 and 27.9 days, respectively. The intrinsic rate of natural increase per day was 0.115. An individual requires at least 30 eggs for nymphal development and survival and 20 eggs for adult oviposition and survival per four days.