Fungal endophytes (FE) are an important component of leaf microbial communities. They usually live asymptomatically within leaf tissues; however, FE can provide additional defensive features against microbial pathogens to the host. Leaf functional traits (LFTs) regulate FE entry, colonization and community composition in plants. There is evidence that thin leaves with less structural and chemical traits but high nutrient content are more prone to FE colonization than well‐defended thick leaves. This illustrates the relevance of trade‐offs (= an increase in a trait, with a decrease in another trait) in LFTs, suggesting that the leaf economics spectrum (LES, which describes relationships in a suite of leaf traits aligned from a resource‐acquisitive to a resource‐conservative ecological strategy) may be a predictor of FE colonization and community composition in plants. We hypothesize that LES‐modulated changes in the leaf internal environment (i.e. thin, low‐defended vs. thick, well‐defended leaves) will (a) have consequences for host resistance to pathogens due to changes in the FE colonization and diversity and, subsequently, in the foliar chemical profile and (b) may cause a switch in FE behaviour to a pathogenic lifestyle. Synthesis. Still, our knowledge of how the coexistence between host plants and FE is regulated remains limited. LFTs may act as relevant ecological hub of FE colonization, community composition and life behaviour in natural ecosystems, with potential bottom‐up effects on other organisms, including pathogens. We highlight and discuss critical aspects in this topic and end by proposing new avenues of research in this emerging field.

Entomopathogenic Hypocreales were isolated from arid soils in Argentina using Tenebrio molitor as bait and tested for their biological performance at 30°C and 45–65% RH. Conidial germination was tested in three vegetable oils (sunflower, olive and maize) at two concentrations (1% and 10%) to evaluate their compatibility for further liquid formulations. According to radial growth and germination results, we selected four isolates to test their pathogenicity against second instar B. tabaci nymphs with the selected oil formulations at 30°C. CEP381 and CEP401 showed the highest radial growth. Isolates CEP381, CEP401, CEP413 and CEP409 (Metarhizium spp.) had similar germination percentages as compared with water control when germinated on either sunflower, olive or maize oils at 10% v/v. The highest mortality of B. tabaci was observed for the isolates CEP381 in sunflower oil and CEP401 in olive oil. Molecular identification of isolates was performed using ITS4–5 primers. All isolates belong to the Metarhizium core group. Tested isolates could grow and infect B. tabaci nymphs at 30°C in some of the vegetable oils as carriers, providing new possibilities for integrated pest management of Bemisia tabaci.

Background: Entomopathogenic fungi (EPF) are the natural enemies of insect pests. Nevertheless, research on the use of EPF for simultaneous prevention of pest and disease agents on the same crop is limited. In this study, we explored the potential dual effects of three strains of the EPF Metarhizium anisopliae on the control of detrimental agents of Vitis vinifera L., including different developmental stages (larvae, pupae, and adult) of the insect pest Lobesia botrana and the phytopathogenic fungus Eutypella microtheca. Methods: Laboratory pathogenicity trials were performed to examine the effects of the three M. anisopliae strains on the mortality rate of L. botrana. In addition, field trials were conducted to assess the biocontrol potential of one selected M. anisopliae strain on the larval stage of L. botrana. Moreover, inhibitory effects of the three EPF strains on E. microtheca growth were examined in vitro. Results: All the M. anisopliae strains were highly effective, killing all stages of L. botrana as well as inhibiting the growth of E. microtheca. The in vitro mortality of larvae treated with the strains was over 75%, whereas that of treated pupae and adults was over 85%. The three EPF strains showed similar efficacy against larvae and adult stages; nevertheless, pupal mortality was observed to be strain dependent. Mortality of L. botrana larvae ranged from 64 to 91% at field conditions. Inhibition of E. microtheca growth reached 50% in comparison to the control. Conclusions: Our study showed that M. anisopliae strains were highly effective in ensuring control of two different detrimental agents of V. vinifera L., providing new evidence to support the dual effects of entomopathogenic fungi.

The European grapevine moth, Lobesia botrana Den. & Schiff. (Lepidoptera: Tortricidae) and the gray rot fungus (Botrytis cinerea) are two important factors that cause elevated losses of productivity in vineyards globally. The European grapevine moth is one of the most important pests in vineyards around the world, not only because of its direct damage to crops, but also due to its association with the gray rot fungus; both organisms are highly detrimental to the same crop. Currently, there is no effective, economic, and eco-friendly technique that can be applied for the control of both agents. On the other hand, Metarhizium anisopliae belongs to a diverse group of entomopathogenic fungi of asexual reproduction and global distribution. Several Metarhizium isolates have been discovered causing large epizootics to over 300 insects’ species worldwide. In this study, a simple design was conducted to evaluate the potential of native M. anisopliae isolates as one of biological control agents against L. botrana and as possible growth inhibitors to B. cinerea. Entomopathogenic fungal strains were isolated from arid soils under vine (Vitis vinifera) culture. Results suggest that the three entomopathogenic strains (CEP413, CEP589, and CEP591) were highly efficient in controlling larval and pupal stages of L. botrana, with mortality rates ranging from 81 to 98% (within 4–6 days). Also, growth inhibition over B. cinerea strains resulted in percentages ranged from 47 to 64%. Finally, the compatibility of the entomopathogenic strains, with seven commercial fungicides, was evaluated. The potential of the entomopathogenic fungal strains to act as control agents is discussed.