Soil-dwelling phages have enormous biocontrol potentials and very little has been documented on the use of phages to enhance soil fertilization with the aim of achieving sustainable plant protection and crop yield. To the best of our knowledge, previous reports on phage therapy and phage biocontrol of plant-related diseases do not focus on assessing the potential of phages in manipulating microbial communities in soils through the application of organic fertilizer. Key methods that have been used to control plant pathogens comprise the foliar application of phages and soil drenching. However, these approaches provide limited biocontrol results. Phage introduction into the soil via soil drench is limited by phage adsorption to clay particles and foliar application potency is impaired by UV radiation inactivation of the phages. This review provides a critical perspective on the sustainability of manipulating physical, chemical, and biological properties of the soil through phage-directed fertilization with the aim of increasing phage abundance, infectivity, and survival within different soil environments.

Recent outbreaks of the invasive alien species Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae) have led to the widespread loss of boxwoods in Europe. Although details on its biology are not fully unraveled, the box tree moth (BTM) can be considered a major pest, severely damaging its primary host, Buxus sempervirens, ultimately affecting the associated coenosis. In European environments, box trees form the Habitat 5110, and BTM outbreaks are seriously endangering its long-term survival.The effectiveness of microbiological treatments with Bacillus thuringiensis var. kurstaki (Btk) on the survival of BTM was evaluated in field and controlled conditions. Given the scant specificity of Btk action, an in-depth survey of its potential impact on non-target diurnal Lepidoptera has been conducted by monitoring their communities’ changes in treated and control areas.Btk spraying was highly effective in the field, and five days after treatments larval density reduction was over 90% in all sites and years, with similar mortality trends achieved in controlled conditions.No significant short-term effects were detected either on non-target diurnal lepidopterans’ abundance or species richness.These results can be combined with the outcomes of spatially explicit models to overcome issues that, up to now, have caused the failure of appropriate strategies to control C. perspectalis. Even if no impact has been observed on non-target Lepidoptera, a rigorous plan for the application, detection and surveillance of the potential effects of microbiological treatments needs to be established.

Non-native invasive arthropod species threaten biodiversity and food security worldwide, resulting in substantial economic, environmental, social and cultural costs. Classical biological control (CBC) is regarded as a cost-effective component of integrated pest management programmes to manage invasive arthropod pests sustainably. However, CBC programmes are traditionally conducted once a pest has established in a new environment, and invariably all research needed to achieve approval to release a biological control agent can take several years. During that time, adverse impacts of the pest accelerate. A pre-emptive biocontrol approach will provide the opportunity to develop CBC for invasive pests before they arrive in the country at risk of introduction and therefore enhance preparedness. A critical aspect of this approach is that risk assessment is carried out in advance of the arrival of the pest. Implementing pre-emptive biocontrol risk assessment means that natural enemies can be selected, screened in containment or abroad and potentially pre-approved prior to a pest establishing in the country at risk, thus improving CBC effectiveness. However, such an approach may not always be feasible. This contribution defines the fundamental prerequisites, principles, and objectives of pre-emptive biocontrol risk assessment. A set of guidelines and a decision framework were developed, which can be used to assess the feasibility of conducting a pre-emptive risk assessment for candidate biological control agents against high-risk arthropod pests.

Fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum is a serious fungal, soil-borne disease that has a dramtic negative impact on the yield and quality of cucumber. In this study, isolates of endophytic bacteria isolated from healthy cucumber plants were evaluated for their ability to inhibit Fusarium wilt. Results indicated that 6 out of 100 of the obtained endophytic bacterial isolates exhibited significant inhibitory activity against mycelial development of F. oxysporum f. sp. cucumerinum, with an inhibition rate > 60 % in dual culture assays. Among the active isolates, strain hg18 exhibited the strongest activity with a 69.57 % rate of inhibition. Strain hg18 was identified as Paenibacillus polymyxa based on morphological, physiological, and biochemical traits, as well as a phylogenetic tree that was constructed using 16S rRNA and rpoB gene sequences. Biological and PCR assays demonstrated that strain hg18 can secrete IAA, a siderophore, hydrolytic enzymes, including protease, cellulase and glucanase, and antimicrobial compounds, such as iturin, fengycin, and non-ribosomal polypeptide synthase, as well as fix nitrogen. Strain hg18 decreased the disease index of cucumber Fusarium wilt and promoted cucumber growth in non-diseased plants in greenhouse experiments, compared to a water treatment. These findings demonstrate the potential of using P. polymyxa hg18 as a biocontrol agent for controlling Fusarium wilt in cucumber.