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We investigated the symbiotic activities of fungal endophytes isolated from spotted knapweed, Centaurea stoebe. Previously, an analysis of community similarity had demonstrated differences in the endophyte communities of C. stoebe in its native and invaded ranges. Here, we found that specific endophytes can exert positive effects on their host, whereas others exert negative effects. Endophytes produced metabolites that inhibited germination of a competitor of C. stoebe. Endophytes also repelled a specialist insect herbivore, perhaps by producing biologically active volatiles. Yet other endophytes acted as cryptic pathogens of C. stoebe, suppressing its germination, reducing its growth, increasing the abundance of a generalist insect herbivore, and delaying or suppressing its flowering. Since, as reported here, endophytes are not functionally interchangeable, previously reported community differences could be contributing to the invasiveness of C. stoebe.

Background and aims Six mutualistic endophytic fungi that are known to colonize the endorhiza have shown biological control properties against plant-parasitic nematodes. In this study we aim to investigate the potential of these endophytic fungi to reduce the phloemfeeding insect Trialeurodes vaporariorum (Westwood) on tomato. Methods To determine the host plant choice of T. vaporariorum, the total number of insects present on each plant was counted daily for 10 days, and then the second leaf below the shoot apex were examined for its chlorophyll content index (CCI).To separate and quantify the active compounds produced in the tomato leaves, a reversed phase high liquid chromatography (RP-HPLC) analysis was performed. Principle results A greenhouse choice test showed that Trichoderma atroviride strain MT-20, T. atroviride strain S-2 and Fusarium oxysporum strain 162 (Fo162) reduced the number of greenhouse whiteflies fifty percent when compared to the untreated control during ten days after insect release. The highest level of biocontrol activity was attained with Fo162. The strains MT20, S-2, and Fo162 all demonstrated acropedal induction of resistance to the insects. The isolate Fusarium sp. strain Bonn-7 enhanced plant growth. The negative effect on insect attraction to the leaves of the endophyte treated plants was not associated with leaf altered chlorophyll content. RP-HPLC analysis revealed that inoculation of the fungus Fo162 induced a change in the accumulation of specific organic compounds in the tomato leaves that could be the cause of insect repellence. Conclusions This study demonstrated the high potential of mutualintic endophytic fungi, in particular of Fo162, to induce resistance in tomato against the phloemfeeding T. vaporariorum.

In 1979, the anthelmintic activity of abamectin, a mixture of avermectins B1a and B1b, was first reported. Since then, multiple articles have investigated avermectins' degradation and its efficacy against a wide variety of pests under different conditions and using different modes of application. However, there is a gap in the literature of analysing abamectin properties and its performance as a non‐fumigant nematicide when applied liquid or granular vs. new avenues of application based on seed and seedling treatment. Therefore, this article reviewed literature to discuss the mode of action, environmental aspects, the nematicidal effectiveness of treatment forms and the range of activity to address these topics.