This article belongs to the Special Issue Entomopathogenic Nematodes: Lethal Parasites of Insects., [Simple Summary] The disease caused by Xylella fastidiosa affects economically relevant crops such as olives, almonds, and grapevine. Since curative means are not available, its current management principally consists of broad-spectrum pesticide applications to control vectors like the meadow spittlebug Philaenus spumarius, the most important one in Europe. Exploring environmentally sound alternatives is a primary challenge for sustainable agriculture. Entomopathogenic nematodes (EPNs) are well-known biocontrol agents of soil-dwelling arthropods. Recent technological advances for field applications, including improvements in obtaining cell-free supernatants from EPN symbiotic bacteria, allow their successful implementation against aerial pests. Here, we investigated the impact of four EPN species and their cell-free supernatants on nymphs of the meadow spittlebug. First, we observed that the exposure to the foam produced by this insect does not affect the nematode virulence. Indeed, direct applications of certain EPN species reached up to 90–78% nymphal mortality rates after five days of exposure, while specific cell-free supernatants produced 64% mortality rates. Overall, we demonstrated the great potential of EPN and cell-free supernatant of their symbiont bacteria applications against this vector, opening new venues to develop novel biopesticides for integrated management practices and organic productions., The meadow spittlebug Philaenus spumarius (Hemiptera: Aphrophoridae) is the primary vector of Xylella fastidiosa (Proteobacteria: Xanthomonadaceae) in Europe, a pest–disease complex of economically relevant crops such as olives, almonds, and grapevine, managed mainly through the use of broad-spectrum pesticides. Providing environmentally sound alternatives to reduce the reliance on chemical control is a primary challenge in the control of P. spumarius and, hence, in the protection of crops against the expansion of its associated bacterial pathogen. Entomopathogenic nematodes (EPNs) are well-known biocontrol agents of soil-dwelling arthropods. Recent technological advances in field applications, including improvements in obtaining cell-free supernatant from their symbiotic bacteria, allow their successful implementation against aerial pests. Thus, this study aimed to evaluate, for the first time, the efficacy of EPN applications against nymphal instars of P. spumarius. We tested four EPN species and the cell-free supernatant of their corresponding symbiotic bacteria: Steinernema feltiae–Xenorhabdus bovienii, S. carpocapsae–X. nematophila, S. riojaense–X. kozodoii, and Heterorhabditis bacteriophora–Photorhabdus laumondii subsp. laumondii. First, we showed that 24 and 72 h exposure to the foam produced by P. spumarius nymphs did not affect S. feltiae virulence. The direct application of steinernematid EPNs provided promising results, reaching 90, 78, and 53% nymphal mortality rates after five days of exposure for S. carpocapsae, S. feltiae, and S. riojaense, respectively. Conversely, the application of the cell-free supernatant from P. laumondii resulted in nymphal mortalities of 64%, significantly higher than observed for Xenorhabdus species after five days of exposure. Overall, we demonstrated the great potential of the application of specific EPNs and cell-free supernatant of their symbiont bacteria against P. spumarius nymphs, introducing new opportunities to develop them as biopesticides for integrated management practices or organic vineyard production., This study was funding by a grant from the Ministry of Science and Innovation (PID2019-104112RB-I00). The researchers were funded by the following agencies and grants:

-
I.V.-D. funded by ADER I + D + i (2019) fellowship by the Rioja Agency of Economic Development (La Rioja, Spain) and currently is supported by an FPU-UR-2020 fellowship.
-
R.B.-P. was supported by the pre-doctoral contracts CAR-2018 (Department of Economic Development and Innovation of the Government of La Rioja).
-
M.d.M.G.-T. is supported by Program JAE-Intro CSIC call 2020 (JAEINT20_EX_0939).
-
R.C.-H. is supported by Ramón y Cajal contract award from the Government of Spain (RYC-2016-19939)., Peer reviewed

Vineyards face several biotic threats that compromise the grape quality and quantity. Among those that cause relevant economic impact and have worldwide distribution are the oomycete Plasmopara vitícola, the fungi Erysiphe necator and Botrytis cinerea, and the arthropods Lobesia botrana, Tetranychus urticae, and Phylaenus spumarius (principal vector of the bacterial disease Xylella fastidiosa in Europe). Their management relies primarily on agrochemicals with short persistence; widespread use of these chemicals causes environmental and human health problems. The challenge of sustainable viticulture is to provide ecologically sound alternatives. In this regard, the application of entomopathogenic nematodes (EPNs) and natural products derived from their symbionts can be an alternative. EPNs are well-known biocontrol agents for soil-dwelling insects. However, current research demonstrates the great potential of both EPN and their derivates as direct bio-tools against some of the key fungal and arthropods pests present aboveground. In addition, recent evidence shows that detecting EPN presence and activity and their relation with other soil organisms associated with them can help us to understand the impact of different agricultural practices on vineyard management. Altogether, this review illustrates the great potential of EPN to enhance pest and disease management in the next generation of viticulture., This review is produced in the context of the grant
awarded from Ministry of Science and Innovation
(PID2019-104112RB-I00). Also, some of the studies
presented were conducted in the framework of the
Interdisciplinar Thematic Platform PTI-SolXyl on Xylella
fastidiosa from CSIC (Spain). RCH is awarded by Ramon
y Cajal contract award (RYC-2016-19939) from the
Government of Spain. IVD is supported with a FPI-UR
(2021) fellowship (Universidad de La Rioja, Spain). RBP
is financed by the Department of Economic Development
and Innovation, Government of La Rioja (Spain) with an
FPI contract (CAR-2018). MC is supported by a Moroccan
scholarship for the Ministry of National Education,
Vocational Training, Higher Education and Scientific
Research, and the travel assistance associated with the
grant CSIC I-COOP+ 2018 grant (COOPA20231).
MMGT is funded by the Programme JAE-Intro CSIC
call 2020 (JAEINT20_EX_0939). MP is funded by an
introduction to research fellowship from Government
of La Rioja (CAR 2020). RC is funded by a postdoctoral
internship from Lituania Goverment supported by EU
funds (LMT-K-712-21-0098).

The European grapevine moth (EGVM) Lobesia botrana (Lepidoptera: Tortricidae) is a relevant pest in the Palearctic region vineyards and is present in the Americas. Their management using biological control agents and environmentally friendly biotechnical tools would reduce intensive pesticide use. The entomopathogenic nematodes (EPNs) in the families Steinernematidae and Heterorhabditidae are well-known virulent agents against arthropod pests thanks to symbiotic bacteria in the genera Xenorhabdus and Photorhabdus (respectively) that produce natural products with insecticidal potential. Novel technological advances allow field applications of EPNs and those bioactive compounds as powerful bio-tools against aerial insect pests. This study aimed to determine the viability of four EPN species (Steinernema feltiae, S. carpocapsae, S. riojaense, and Heterorhabditis bacteriophora) as biological control agents against EGVM larval instars (L1, L3, and L5) and pupae. Additionally, the bioactive compounds from their four symbiotic bacteria (Xenorhabdus bovienii, X. nematophila, X. kozodoii, and Photorhabdus laumondii subsp. laumondii, respectively) were tested as unfiltered ferment (UF) and cell-free supernatant (CFS) against the EGVM larval instars L1 and L3. All of the EPN species showed the capability of killing EGVM during the larval and pupal stages, particularly S. carpocapsae (mortalities of ~50% for L1 and >75% for L3 and L5 in only two days), followed by efficacy by S. feltiae. Similarly, the bacterial bioactive compounds produced higher larval mortality at three days against L1 (>90%) than L3 (~50%), making the application of UF more virulent than the application of CFS. Our findings indicate that both steinernematid species and their symbiotic bacterial bioactive compounds could be considered for a novel agro-technological approach to control L. botrana in vineyards. Further research into co-formulation with adjuvants is required to expand their viability when implemented for aboveground grapevine application., This research was funded by the following institutions (name: reference), MCIN/AEI/
10.13039/501100011033: Grant PID2019-104112RB-I00, University of La Rioja: FPI-UR-2020, Department
of Economic Development and Innovation of the Government of La Rioja: FPI-CAR-2018,
Rioja Agency of Economic Development: ADER I+D+i (2019), CSIC I-COOP+ 2018: COOPA20231,
Government of La Rioja: Intro-CAR 2020, MCIN/AEI/10.13039/501100011033 and by “ESF Investing
in your future”: Grant RYC-2016-19939., Peer reviewed

Experiment performed in the lab, following details described in the publication (http://hdl.handle.net/10261/240920 / https://doi.org/10.3390/insects12050448), Grants ICVV-CSIC:

Ministry of Science and Innovation (PID2019-104112RB-I00) funded by MCIN/AEI/10.13039/501100011033.

Support for researchers:

1) RCH is awarded by Ramon y Cajal contract award MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”: Grant RYC-2016-19939 from the Government of Spain
2) IVD is I.V.-D. funded by ADER I + D + i (2019) fellowship by the Rioja Agency of Economic Development
(La Rioja, Spain) and by FPI-UR (2021) fellowship (Universidad de La Rioja, Spain).
4) MMGT is funded by the Program JAE-Intro CSIC call 2020 (JAEINT20_EX_0939).
5) R.B.-P. was supported by the pre-doctoral contracts CAR-2018 (Department of Economic Development and Innovation of the Government of La Rioja)., Peer reviewed

Experiment performed in the lab, following details described in the publication: https://doi.org/10.3390/insects12111033 / http://hdl.handle.net/10261/262517, Grants ICVV-CSIC:

Ministry of Science and Innovation (PID2019-104112RB-I00) funded by MCIN/AEI/10.13039/501100011033.

Support for researchers:

1) RCH is awarded by Ramon y Cajal contract award MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”: Grant RYC-2016-19939 from the Government of Spain
2) IVD is I.V.-D. funded by ADER I + D + i (2019) fellowship by the Rioja Agency of Economic Development (La Rioja, Spain) and by FPI-UR (2021) fellowship (Universidad de La Rioja, Spain).
3) MP is funded by an introduction to research fellowship from the Government of La Rioja (CAR 2020).
4) MC was supported by the travel assistance is associated with the CSIC I-COOP+ 2018 grant (COOPA20231) and a Moroccan scholarship for the Ministry of National Education, Vocational Training, Higher Education, and Scientific Research
5) RBP was supported by the pre-doctoral contracts CAR-2018 (Department of Economic Development and Innovation of the Government of La Rioja)., Peer reviewed

The grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae), is a critical pest for vineyards and causes significant economic losses in wine-growing areas worldwide. Identifying and developing novel semiochemical cues (e.g. volatile bacterial compounds) which modify the ovipositional and trophic behaviour of L. botrana in vineyard fields could be a novel control alternative in viticulture. Xenorhabdus spp. and Photorhabdus spp. are becoming one of the best-studied bacterial species due to their potential interest in producing toxins and deterrent factors. In this study, we investigated the effect of the deterrent compounds produced by Xenorhabdus nematophila and Photorhabdus laumondii on the ovipositional moth behaviour and the larval feeding preference of L. botrana. Along with the in-vitro bioassays performed, we screened the potential use of 3 d cell-free bacterial supernatants and 3 and 5 d unfiltered bacterial ferments. In addition, we tested two application systems: (i) contact application of the bacterial compounds and (ii) volatile bacterial compounds application. Our findings indicate that the deterrent effectiveness varied with bacterial species, the use of bacterial cell-free supernatants or unfiltered fermentation product, and the culture times. Grapes soaked in the 3 d X. nematophila and P. laumondii ferments had ∼ 55% and ∼ 95% fewer eggs laid than the control, respectively. Likewise, the volatile compounds emitted by the 5 d P. laumondii fermentations resulted in ∼ 100% avoidance of L. botrana ovipositional activity for three days. Furthermore, both bacterial fermentation products have larval feeding deterrent effects (∼65% of the larva chose the control grapes), and they significantly reduced the severity of damage caused by third instar larva in treated grapes. This study provides insightful information about a novel bacteria-based tool which can be used as an eco-friendly and economical alternative in both organic and integrated control of L. botrana in vineyard., The authors thank Elisabet Vaquero Jiménez and Miguel Puelles for their invaluable assistance in the laboratory. The predoctoral contract FPI-UR 2021 (University of La Rioja) support IVD. This study was also funded by the Ministry of Science and Innovation, grant PID2019-104112RB I00 (MCIN/AEI/10.13039/50110001103)., Peer reviewed

Statistical data described in the article and the solfware SPSS and the charts with Prism Graphpad 8.0 (Prism). Repetition of all the experiments (two times eachs), check of the controls, assurance of good and reproducible conditions., Experiment performed in the lab, following details described in the publication: https://doi.org/10.1016/j.jip.2023.107911; http://hdl.handle.net/10261/304637, Ministry of Science and Innovation, grant PID2019-104112RB I00 (MCIN/AEI/10.13039/50110001103). The predoctoral contract FPI-UR 2021 (University of La Rioja) support IVD, Peer reviewed

The pathogen Botrytis cinerea (Helotiales: Sclerotiniaceae) is a wound necrotrophic fungus that causes significant losses in fruits and vegetables worldwide. The entomopathogenic nematode (EPN) symbiotic bacteria, Xenorhabdus spp. and Photorhabdus spp., are well-known associated biological control agents that produce a diverse range of natural antifungal compounds. This study aimed to evaluate the efficacy of different control strategies against B. cinerea using: (i) EPN symbiotic bacterial cell-free supernatants, (ii) unfiltered ferments and (iii) crude bacteria isolates. The antifungal efficacy of X. bovienii, X. nematophila, X. kozodoii and P. laumondii subsp. laumondii cell-free supernatants obtained after the bacterial fermentations were tested in vitro at two different concentrations (10% and 20%). Furthermore, the antifungal effect of X. nematophila and P. laumondii unfiltered ferments were tested in vitro, and their dissuasive effect was also tested over tomato leaves. Finally, the antifungal capacity of the crude X. nematophila and P. laumondii isolate was tested comparing their effect with the fungicide effect of the commercial Bacillus amyloliquefaciens (Serenade® ASO fungicide). The results showed that employing the bacterial cell-free supernatants or the unfiltered ferments could have different antifungal efficacy against this pathogen. Applying X. nematophila cell-free supernatant and unfiltered ferments at 20% concentration resulted in the highest inhibition effect compared with the control (distilled water), 82% and 100%, respectively. Furthermore, P. laumondii-isolate can control the growth of Botrytis in in vitro conditions, showing no significant differences with the efficacy of Bacillus amyloliquefaciens in a four-day experiment. Overall, this study builds on a better understanding of the effects of these novel biocontrol agents against B. cinerea and helps to develop an innovative formulation of these bacterial products as an efficient biocontrol tool., The authors thank Elisabet Vaquero Jiménez for their invaluable assistance in the laboratory, and members of Biovitis Lab and VitisGen (ICVV) for kindly sharing their equipment. The pre-doctoral contract FPI-UR 2021 (University of La Rioja) support IVD. The Erasmus+ - KA1 Erasmus Mundus Joint Master Degrees Program of the European Commission under the PLANT HEALTH Project supported EC stage at ICVV. This research was funded by the Ministry of Science and Innovation, grant PID2019-104112RB-I00 (MCIN/AEI/10.13039/50110001103) and by the Instituto de Estudios Riojanos (IER, Government of La Rioja, Spain, ref. 29/2022., Peer reviewed

Statistical data described in the article and the solfware SPSS and the charts with Prism Graphpad 8.0 (Prism). Repetition of all the experiments (two times eachs), check of the controls, assurance of good and reproducible conditions., Experiment performed in the lab, following details described in the publication: https://doi.org/10.1016/j.biocontrol.2023.105259; http://hdl.handle.net/10261/333898, Ministry of Science and Innovation, grant PID2019-104112RB I00 (MCIN/AEI/10.13039/50110001103). The predoctoral contract FPI-UR 2021 (University of La Rioja) support IVD

The Erasmus+ - KA1 Erasmus Mundus Joint Master Degrees Program of the European Commission under the PLANT HEALTH Project supported EC., Peer reviewed

Lobesia botrana (Lepidoptera: Tortricidae) is a crucial grapevine pest worldwide. Expanding the available biocontrol agents can provide new management strategies compatible with organic viticulture. Entomopathogenic nematode (EPN) potential as a biocontrol agent was demonstrated against various developmental stages of L. botrana. For its field application, we hypothesised that by selecting the best combination of EPN-adjuvant and identifying the best area/timing for their application, we will secure their effective implementation against L. botrana. The aim of this study was to determine the best ecological scenarios for their use against L. botrana. We investigate three EPN species naturally occurring in Riojan vineyards: Steinernema feltiae, S. carpocapsae, and Heterorhabditis bacteriophora. We evaluated (i) EPN viability, infectivity, and adherence on leaves combined with adjuvants (Multi-Us, Maximix, Dash HC, Nu-Film-17, and Adrex), (ii) EPN biocontrol against L. botrana larva on leaves and grapes and damage reduction, and (iii) EPN efficacy against L. botrana at 22°, 15°, and 10 °C. Overall, all the adjuvants were compatible with the EPN, except Adrex with Heterorhabditis bacteriophora. Compared with the no application, EPNs (steinernematids) alone or with Maximix increased L. botrana L3 mortality on grapes and leaves, thereby reducing the damage. Pupal mortality caused by steinernematids EPN (alone or with Maximix) decreased with temperature, from ∼60% at 22 °C to <30% at 10 °C. Overall, steinernematids EPN (alone or with Maximix) applied against L. botrana on leaves, grapes, or trunks reduced the damage and increased insect mortality. This study suggests the best-case scenario for the application of EPNs is at sunset during late spring/early autumn at mid-temperatures (22 °C-15 °C). Further field validation is necessary for their full implementation., We thank José Luis Ramos Sáenz de Ojer from the Government of La Rioja for their support in the selection of the adjuvants investigated in this study. We also thank Anna Gámez Sánz, Javier Villaro Tricio, and José Ramón Ramos Acedo for their technical support in some of the studies. The pre-doctoral contracts FPI-UR-2020, FPI-CAR-2022, and FPI-UR-2022 (University of La Rioja) support Ignacio Vicente-Díez, María del Mar González-Trujillo and Miguel Puelles, respectively. The Erasmus+ - KA1 Erasmus Mundus Joint Master Degrees Program of the European Commission under the PLANT HEALTH Project supported Elizabeth Carpentero's stage at ICVV. A postdoctoral internship from the Lituania government supported by EU funds (LMT-K-712-21-0098) was awarded to Rasa Cepulyte. This study was also funded by the Ministry of Science and Innovation, grant PID 2019-104112RB-I00 (MCIN/AEI/10.13039/50110001103)., Peer reviewed

Statistical data described in the article and the solfware SPSS. Repetition of all the experiments (two times eachs), check of the controls, assurance of good and reproducible conditions., Experiment performed in the lab, following details described in the publication: https://doi.org/10.1016/j.cropro.2023.106392. http://hdl.handle.net/10261/334329, Ministry of Science and Innovation, grant PID2019-104112RB I00 (MCIN/AEI/10.13039/50110001103). IVD was financed by a FPI-UR 2020 from University of La Rioja
MMGT was financed by a FPI-CAR-2022 from University of La Rioja
MP was financed by a FPI-UR-2022 from University of La Rioja
EC was financed by the Erasmus+ - KA1 Erasmus Mundus Joint Master Degrees Program of the European Commission under the PLANT HEALTH Project
RC was financed by EU funds (LMT-K-712-21-0098), Peer reviewed

Post-harvest fruit and vegetable rot produced by Botrytis cinerea (Helotiales: Sclerotiniaceae) causes significant reductions in food availability and drastically increases economic losses. The use of microbial-based tools for pathogen management holds promise. In particular, volatile organic compounds (VOCs) emitted by microbes (e.g., bacterial compounds) are becoming increasingly more frequent as an alternative to chemical and physical treatments. In this study, we performed three laboratory experiments to investigate the effects of VOCs emitted by two gram-negative entomopathogenic bacteria, Xenorhabdus nematophila, and Photorhabdus laumondii subsp. laumondii, on the infection and growth of the pathogenic mold B. cinerea on post-harvest red grapes and tomatoes. In addition, we evaluated the preventive effects of these bacterial VOCs against pathogens in post-harvest wounded and intact grapes. Overall, VOCs emitted by X. nematophila and P. laumondii limited the lesion area of B. cinerea to 0.5% and 2.2%, respectively, on the grapes. Similarly, VOCs emitted by X. nematophila and P. laumondii limited the lesion area of B. cinerea to 0.5% and 0.02%, respectively, in tomatoes. In addition, the emission of VOCs by both bacteria showed strong preventive fungal effects. In particular, VOCs emitted by P. laumondii reduced to 13% B. cinerea incidence in damaged grapes exposed to VOCs. Moreover, intact grapes exposed to VOCs emitted by X. nematophila and P. laumondii decreased B. cinerea incidence by 33%. This study provides insightful information about a potential novel bacteria-based tool that can be used as an alternative in the integrated control of post-harvest diseases., The authors thank Elisabet Vaquero Jiménez for her invaluable assistance in the laboratory, and members of Biovitis Lab and VitisGen (ICVV) for kindly sharing their equipment. The pre-doctoral contract FPI-UR 2021 (University of La Rioja) support IVD. Similarly, RCH received the Grant RYC-2016-19939 funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future”. This study was also funded by the Ministry of Science and Innovation, Grant PID2019-104112RB-I00 (MCIN/AEI/10.13039/50110001103)., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature., Peer reviewed

Experiment performed in the lab, following details described in the publication https://doi.org/10.1007/s10526-023-10212-7, Grant PID2019-104112RB I00 from Ministry of Science and Innovation (MCIN/AEI/10.13039/50110001103).

Grant RYC-2016-19939 funded by Ministry of Science and Innovation (MCIN/
AEI/ 10.13039/501100011033) and “ESF Investing in your future”.
The predoctoral contract FPI-UR 2021 (University of La Rioja) support IVD, Peer reviewed

Vineyards, covering over seven million hectares worldwide, holdsignificant socio-cultural importance. Traditionally reliant onconventional practices and agrochemicals, this agroecosystemfaces environmental challenges, including soil and water pollution.Sustainable viticulture, driven by eco-friendly practices and costreduction, has gained prominence, underlining the importance ofbiological control agents such as entomopathogenic nematodes(EPNs). EPNs naturally occurr in vineyard soils and play a crucial rolein controlling pest damage. Ensuring compatibility between EPNsand the commonly used vineyard fungicides is critical, as theseapplications constitute the predominant pest-management practiceduring the productive grapevine cycle.This study assessed the impact of authorized grapevinefungicides on EPNs, focusing on the survival of populations andsublethal effects on their virulence. We investigated the compatibilityof two EPN populations (Steinernema feltiae 107 and S. carpocapsae‘All’) with three organic production-approved products (Bacilluspumilus, sulfur, and copper oxychloride) and two synthetic chemicals(Trifloxystrobin and Mancozeb). Our findings revealed that the viabilityof S. feltiae 107 was reduced when exposed to sulfur and copperoxychloride, and its virulence was affected by copper oxychlorideand Mancozeb, although only two days after exposure and with nosignificant differences for larval mortality at five days.In contrast, S. carpocapsae ‘All’ exhibited full compatibilitywith all five fungicides, with no impact on its viability or virulence.Consequently, our results suggested that the evaluated fungicidescould be co-applied on both EPN populations if they were employedon the same day. However, further research on multi-targetinteractions is needed to ensure the successful implementation ofthis kind of co-application, The Erasmus+ - KA1 Erasmus Mundus Joint Master
Degrees Program of the European Commission under
the PLANT HEALTH Project supported Elizabeth
Carpentero’s stage at ICVV. The predoctoral contract
FPI-UR-2022 (University of La Rioja) supported Miguel
Puelles. This study was also funded by the Ministry of
Science and Innovation, grant PID 2019-104112RBI00
(MCIN/AEI/10.13039/50110001103). This study
forms part of the AGROALNEXT programme and
was supported by MCIN with funding from European
Union NextGenerationEU (PRTR-C17.I1)., Peer reviewed

Experiment performed in the lab, following details described in the publication:https://doi.org/10.2478/jofnem-2023-0057, Ministry of Science and Innovation, grant PID2019-104112RB I00 (MCIN/AEI/10.13039/50110001103).
AGROALNEXT programme, by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1).
MP was financed by a FPI-UR-2022 from University of La Rioja
EC was financed by the Erasmus+ - KA1 Erasmus Mundus Joint Master Degrees Program of the European Commission under the PLANT HEALTH Project, Peer reviewed

Ensuring global food security requires innovative tools for crop pest/diseases management. Beneficial microorganisms can protect plants from pests, enhancing disease resistance, and abiotic stress tolerance. Entomopathogenic bacteria are beneficial microorganisms with an obligate or facultative action against arthropods. Entomopathogenic bacteria perform on different host ranges and are well-known biological control agents. Their direct agricultural application requires a fine-tuned adjustment for several biotic and abiotic factors and a more profound knowledge of their infective mechanisms. The search for new natural products generated by entomopathogenic bacteria is an alternative for producing new antibiotic compounds with the potential for plant protection. The discovery and characterization of these new natural products can significantly contribute to advances in novel biotools that can cope with the urgent need for alternatives for farmers. This chapter summarizes the forefront research in these new areas and discusses the array of agricultural crop benefits and potential scopes produced by Xenorhabdus and Photorhabdus entomopathogenic bacteria., The authors thank the support of IVD by the pre-doctoral contract FPI-UR 2021 (University of La Rioja, Spain). The study presented is linked to the research performed in the frame of the national grant reference PID2019-104112RB-I00 from MCIN/AEI/10.13039/501100011033.

[Description of methods used for collection/generation of data] Experiment performed in the laboratory and semifield conditions, following details described in the publication., [Methods for processing the data] R software version 4.3.2 (R Core Team, 2023). All graphs were built using ggplot2 package., Viticulture is a global activity that annually yields over eighty million tonnes of grapes, 50 % used in winemaking. Traditional viticultural practices still rely on hazardous pesticides, posing environmental and health risks. Recently, Xenorhabdus and Photorhabdus, symbiotic bacteria of entomopathogenic nematodes, have arisen as eco-friendly solutions for pest and disease management in vineyards. However, whether their application can impact the quality attributes of grapes and their microbiota remains unexplored. To unravel the possible impact, we investigated (i) the impact of direct application on grapes' volatile composition and (ii) the combination with must and Saccharomyces cerevisiae fermentation. First, we applied unfiltered ferments (UFs) of Xenorhabdus nematophila and Photorhabdus laumondii to grapes of Vitis vinifera var. "Tempranillo". The volatile composition of the grapes was evaluated using solid-phase and gas chromatography-mass spectrometry (SPE-GC/MS). Second, microfermentations using reconstituted must media were supplemented (1:10) with the treatments (i) cell-free supernatants (CFS), (ii) UFs, and (iii) free-bacterial from X. nematophila and P. laumondii. No significant alterations in the total free volatile fraction were observed, although specific free volatiles (phenylethyl alcohol, hexanal and E-2-hexenal), exhibited significant variation under specific treatments. In the glycosidically bound fraction, phenylacetic acid concentrations increased markedly with X. nematophila UFs. In the fermentations, the treatments had no significant impact on CO2 production kinetics, only slightly affecting some fermentation parameters, underscoring their compatibility with yeast-driven fermentation processes. These findings suggest that Xenorhabdus and Photorhabdus can be safely integrated into vineyard pest management strategies without adversely affecting essential winemaking parameters or grape aroma quality., Ministry of Science and Innovation, grants PID2019-104112RB-I00 and PID2022-136487OB-I00 (MCIN/AEI/10.13039/50110001103)., Support for researchers: The predoctoral contract FPI-UR 2021 (University of La Rioja) support IVD., Peer reviewed