The poinsettia thrips Echinothrips americanus Morgan is a relatively new pest that has spread rapidly worldwide and causes serious damage in both vegetable and ornamental plants.In this study,we investigated if and ho...The poinsettia thrips Echinothrips americanus Morgan is a relatively new pest that has spread rapidly worldwide and causes serious damage in both vegetable and ornamental plants.In this study,we investigated if and how effective this pest can be controlled in gerbera by the omnivorous predator Macrolophus pygmaeus(Rambur).Because herbivores on plants can interact through a shared predator,we also investigated how poinsettia thrips control is affected by the presence of the greenhouse whitefly Trialeurodes vaporariorum(Westwood),a pest that commonly coexists with E.americanus in gerbera.In laboratory studies,we found that the predator M.pygmaeus fed on both pests when offered together.Olfactometer tests showed a clear preference of the predators for plants infested by whiteflies but not by thrips.In a greenhouse experiment,densities of both pests on single gerbera plants were reduced to very low levels by the predator,either with both pests present together or alone.Hence,predator‐mediated effects between whiteflies and thrips played only a minor role.The plant feeding of the shared predator probably reduced the dependence of predator survival and reproduction on the densities of the two pests,thereby weakening potential predator‐mediated effects.Thus,M.pygmaeus is a good candidate for biological control of both pests in gerbera.However,further research is needed to investigate pest control at larger scales,when the pests can occur on different plants.展开更多
基金This study was funded by the Dutch Product Board for Horticulture.Part of this work was supported by COST Action FA 1105:Towards a sustainable and productive EU organic greenhouse horticulture.
文摘The poinsettia thrips Echinothrips americanus Morgan is a relatively new pest that has spread rapidly worldwide and causes serious damage in both vegetable and ornamental plants.In this study,we investigated if and how effective this pest can be controlled in gerbera by the omnivorous predator Macrolophus pygmaeus(Rambur).Because herbivores on plants can interact through a shared predator,we also investigated how poinsettia thrips control is affected by the presence of the greenhouse whitefly Trialeurodes vaporariorum(Westwood),a pest that commonly coexists with E.americanus in gerbera.In laboratory studies,we found that the predator M.pygmaeus fed on both pests when offered together.Olfactometer tests showed a clear preference of the predators for plants infested by whiteflies but not by thrips.In a greenhouse experiment,densities of both pests on single gerbera plants were reduced to very low levels by the predator,either with both pests present together or alone.Hence,predator‐mediated effects between whiteflies and thrips played only a minor role.The plant feeding of the shared predator probably reduced the dependence of predator survival and reproduction on the densities of the two pests,thereby weakening potential predator‐mediated effects.Thus,M.pygmaeus is a good candidate for biological control of both pests in gerbera.However,further research is needed to investigate pest control at larger scales,when the pests can occur on different plants.
