Paraisaria gracilis

Paraisaria gracilis is an entomopathogenic fungus known for its role as a biological agent that causes lethal mycoses in various insect species. In the context of agronomy, it is categorized as a beneficial microorganism that helps regulate pest populations by infecting insects residing in soil or organic debris.

The causative agent belongs to the Cordycipitaceae family. It functions by penetrating the host's cuticle, colonizing its internal tissues, and effectively killing the insect through a combination of physical structural damage and toxic metabolic byproducts.

The fungus affects a variety of pest species, particularly those belonging to the orders Lepidoptera, Coleoptera, and Hymenoptera. It is highly effective against larvae and pupae that remain in the topsoil, where the fungus thrives, potentially reducing the necessity for synthetic pesticides during early growth stages.

Symptoms of the infection include:

• Gradual loss of mobility in the infected insect;
• Development of a distinct white, fuzzy mycelium on the exterior of the host;
• Mummification of the host body;
• Emergence of fungal fruiting bodies once the host has perished.

Development and spreading are heavily dependent on environmental factors, primarily high humidity and temperate conditions. To preserve and encourage the presence of this beneficial fungus, farmers should avoid the excessive use of broad-spectrum fungicides that negatively impact the soil microbiome and favor sustainable soil management practices.