Author: Richard Stouthamer

Goal of the work was to improve obtain natural enemies for the Polyphagous and Kuroshio shot hole borers in California. Natural enemies are present in the native range of the beetles Taiwan.  Cooperation was obtained from local scientists to try to establish lab populations of natural enemies: parasitoids and nematodes.  In general, it is difficult to establish laboratory cultures of these natural enemies, because of the hidden lifestyle of the beetles and consequently the parasitization could not be observed.  Cooperators were not able to establish beetle parasitoid populations in the lab, no successful offspring was obtained from the wasps exposed to beetle containing logs of wood.  As a result we decided to try to establish cultures ourselves from field collected infested avocado wood in Taiwan. Two trips were made were we collected large numbers of avocado branches from near Tainan in Taiwan and shipped them to our quarantine facility at UCR. The January trip resulted in 169 parasitoids (5 species) emerging and May trip in 112 parasitoids (5 species). Long-term rearing at UCR was not successful from the January trip one generation of offspring was obtained, while the May trip resulted in up to 3 generations of offspring before the cultures died out.