Endophytic Fusarium oxysporum strain V5w2 has been suggested to offer the ecosystem service of suppressing Cosmopolites sordidus and other pests that attack tissue culture banana plants in agroecosystems. The effects of endophytic F. oxysporum V5w2 and nutrient supply on C. sordidus in potted tissue culture banana plants were investigated. In the screenhouse, rhizome damage by C. sordidus larvae was lower in F. oxysporum V5w2-inoculated plants than in non-inoculated ones. Banana plants inoculated with F. oxysporum V5w2 were larger and suffered less rhizome damage but with low chlorophyll content. Weights of C. sordidus larvae were not different between those reared on F. oxysporum V5w2-inoculated banana plants and the non-inoculated ones. Larval C. sordidus from nutrient-treated plants had lower weight than those that fed on plants that did not receive nutrients. In the field, fewer adult C. sordidus were found on F. oxysporum V5w2inoculated banana plants than on non-inoculated plants 12 h after insect release. The number of adult C. sordidus and their eggs did not vary between F. oxysporum V5w2-inoculated banana plants and controls at the end of the experiment. Adult C. sordidus did not discriminate between nutrient-treated banana plants and those without nutrient treatment. However, non-beneficial interactions between F. oxysporum V5w2 and plant-parasitic nematodes negate the chances of its application as an endophytic biological control agent. In conclusion, while F. oxysporum V5w2 is not quite viable for application as an endophytic biological control agent for C. sordidus and other banana pests, this fungus may still have some potential to offer alternative ecosystem services through the provisioning of pest-inhibitive organic compounds.

Plant parasitic nematodes (PPN) and fungi cause biotic stress and are responsible for considerable yield losses to different crops. PPN and fungi are very abundant microorganisms in soil and both interact with each other in multiple ways. PPN besides causing direct damage to plants, also possess capability to interact with fungi resulting into disease complexes. The PPN invasion in plant parts especially in root may enhance severity of fungal diseases in many instances. This review critically analyses the information on the combined nematode-fungus stress and economic losses caused by them. Combined PPN and fungal stress has been discussed which results into synergistic and additive interactions. Similarly, role of wounds created by nematode feeding, physiological changes in the host, modification in rhizosphere, breaking of host resistance and changes in the host plant due to combined interaction of PPN-fungus has been described. Role of PPN and fungus in antagonistic interaction has also been analysed. Role of microbial communities in the rhizosphere in influencing nematode-fungus interaction has also been discussed. Management of disease complexes using mixture of biocontrol agents and use of nanoparticles in integrated management has been suggested. Conclusion and future prospects have been discussed.