Formulation Strategies for Fungal Biocontrol of Gastrointestinal Helminths in Domestic Animals and Plant-Parasitic Nematodes: A Review

Although microbial biopesticides are expanding rapidly, transforming nematophagous fungi into consistent and shelf-stable products remains a challenge. A key limitation is that fungal propagules must remain viable throughout production, storage, and delivery to ensure their efficacy in the field. This review examines formulation strategies that improve the stability, deployment, and performance of fungal biocontrol agents against gastrointestinal helminths in domestic animals and plant-parasitic nematodes. In veterinary systems, predatory fungi such as Duddingtonia flagrans primarily target infective larvae after surviving gastrointestinal transit and germination in feces. In contrast, ovicidal fungi, including Pochonia chlamydosporia, Purpureocillium lilacinum, Trichoderma spp., and Mucor spp., primarily act against helminth eggs and coccidian oocysts. This functional complementarity highlights the potential of combined fungal formulations to improve their control efficacy. We also discuss the currently available D. flagrans-based commercial products, BioWorma® and Bioverm®, and the practical challenges associated with dosing, administration, and farm adoption. In agriculture, we show that the Brazilian market is dominated by solid fungal nematicides designed to reduce water activity and prolong shelf life, although liquid- and oil-based systems remain relevant for specific applications. Across both sectors, the review identified formulation design, rather than fungal species alone, as a critical determinant of product performance. Emerging advances, such as microencapsulation, UV-protective matrices, improved seed-coating biopolymers, nanobiotechnology, and fungal-derived bioactive products, indicate that future progress will depend on target-oriented formulations capable of increasing stability, controlled release, and resilience under environmentally variable conditions, including those imposed by climate change.