“There are several commercial microorganisms (bacteria and fungi), as well as entomopathogenic viruses used in the management of insect and mite pests…”
Nathalie Prado Maluta is a postdoctoral researcher at the Laboratory of Insect Vectors of Phytopathogens at ESALQ-USP, has a degree in agronomic engineering from UEL, a M.Sc. and Ph.D. in Entomology from Esalq/USP, a postdoctoral degree in Plant Health from IAC and in Entomology from SPARCBio.
Nathalie Maluta, postdoc at ESALQ-USP
AgriBrasilis – What are entomopathogenic fungi?
Nathalie Maluta – They are microorganisms that cause diseases in insects and mites, colonizing them, affecting their behavior and leading to their death.
AgriBrasilis – What are the agricultural uses of the Cordyceps javanica fungus?
Nathalie Maluta – This fungus is used in agriculture to control citrus pest insects and mites such as the citrus Asian psyllid, Brevipalpus phoenicis, and Phyllocoptruta oleivora, as well as to control corn leafhoppers (Dalbulus maidis), and has a great potential to control other pests in different crops.
“Biological control using entomopathogenic microorganisms is another tool in Integrated Pest Management (IPM), which has demonstrated excellent results in pest control”
AgriBrasilis – SPARCBio has just identified the mechanism by which the fungus acts against the corn leafhopper (Dalbulus maidis). What were the conclusions? How does the fungus affect the insect’s behavior?
Nathalie Maluta – The study showed that the fungus C. javanica (previously called Isaria fumosorosea or Cordyceps fumosorosea) begins to affect the behavior of the corn leafhopper 48 hours after the spraying of the bioinsecticide, reducing the insects’ feeding activity, mainly in the phloem vessels of corn plants, where the transmission of phytopathogens by this species of leafhopper occurs, indicating a decrease in disease transmission and direct damage to the crops.
The results were published in the journal Scientific Reports (www.nature.com/articles/s41598-023-48779-x).
AgriBrasilis – What methodology was used for identification? Could this method have other applications in agriculture?
Nathalie Maluta – The Electrical Penetration Graph (EPG) technique was used, which consists of connecting the insect and plant to an electrical circuit, allowing the association of waveforms – produced by the insect’s feeding activity directly on the computer monitor – with biological activities within the plant tissues.
This technique is used to evaluate the feeding behavior of sucking insects (whiteflies, leafhoppers, psyllids, aphids, etc.) and can be applied to evaluate the resistance of plant varieties to insects, the effect of chemical and biological insecticides on feeding behavior; in studies involving the transmission of phytopathogens by vectors, etc.
AgriBrasilis – How are C. javanica-based products applied?
Nathalie Maluta – The products are sprayed in the same way as traditional insecticides, mixed in the phytosanitary solution, following the recommendations of the manufacturing company.
AgriBrasilis – How long after the application is completed are effects observed on the targets?
Nathalie Maluta – The effects of Cordyceps javanica-based products depend on the target, and may vary both in terms of how the effects are verified and in terms of the time it takes for the fungus to act on the targets.
In insects such as the Diaphorina citri, the effects on feeding behavior were evident a few hours after spraying, while in the case of Dalbulus maidis, the effects on feeding behavior were evident 48 hours after application.
AgriBrasilis – How efficient is pest control through the use of fungus?
Nathalie Maluta – Biological control using entomopathogenic microorganisms is another tool in Integrated Pest Management (IPM), which has demonstrated excellent results in pest control and in helping to manage resistance to agrochemicals in different crops. However, like all control methods, it should only be used when necessary and following the manufacturer’s recommendations.
AgriBrasilis – What other entomopathogenic fungi are used in agriculture and for what purposes?
Nathalie Maluta – There are several commercial microorganisms (bacteria and fungi), as well as entomopathogenic viruses used in the management of insect and mite pests. Among the fungi, the most used are Beauveria bassiana and species of the genus Metarhizium, in addition to Cordyceps javanica.
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