Development of Mycoinsecticides: Advances in Formulation, Regulatory Challenges and Market Trends for Entomopathogenic Fungi

Abstract

Bioinsecticides offer eco-friendly alternatives to chemical insecticides and thereby meet the need for sustainable pest control. Entomopathogenic fungi (EPF) represent one of the core classes of microbial insecticides, distinguished by their advantageous contact-based mode of action. Several products have been successfully commercialized, and with continuing improvements to the technology, the market size for EPF continues to grow. The translation of EPF into reliable field performers relies upon formulation technologies that ensure product quality, stability, virulence, and cost-effectiveness. Current formulations comprise diverse solid and liquid states (e.g., wettable powders, oil dispersions) that deliver a range of propagules (conidia, blastospores, microsclerotia). While advanced approaches like nanoparticle encapsulation show promise, some limitations hinder their widespread use. Major constraints include maintaining fungal viability during storage/transport and protecting propagules from harsh environmental factors post-application. Regulatory requirements also present significant barriers to widespread uptake. Addressing these formulation challenges through continued research is essential for advancing mycoinsecticide technology and increasing their contribution to integrated pest management. This review aims to present the latest scientific advances in EPF formulation technologies and application strategies, alongside an overview of current regulatory frameworks and an up-to-date analysis of registered microbial biopesticide products in some of the world's largest markets.

Keywords: entomopathogenic fungi; formulation; microbial control; mycoinsecticides.

Figure 1

General infection cycle of a hypocrealean entomopathogenic fungus. The cycle begins with conidial attachment to the host cuticle via hydrophobic interactions. Under favorable conditions (e.g., temperature, humidity, nutrient availability), conidia germinate, potentially forming specialized structures (e.g., appressoria) to breach the cuticle. The fungus then penetrates the host using mechanical pressure and enzymatic degradation (e.g., proteases, chitinases, lipases), reaching the hemocoel. Within the host, the fungus differentiates into hyphal bodies and blastospores, consuming nutrients in the hemolymph, colonizing tissues through vegetative growth, and producing insecticidal, immunosuppressive, and antibiotic secondary metabolites, ultimately causing host death. Under suitable conditions, the fungus emerges from the cadaver, forms conidiophores and produces new conidia, which are dispersed (via wind, rain, animal vectors) and can infect new hosts. Adapted from Mascarin and Jaronski [23].

Figure 2

Several types of ingredients (gray boxes) can be incorporated into formulations, providing different benefits (pink boxes). The most common types of formulations of entomopathogenic fungi are shown in the yellow boxes.

Figure 3

Innovative formulation strategies for entomopathogenic fungi (EPF). (A) Biopolymer encapsulation commonly utilizes alginate, chitosan or starch, although other biopolymers can also be employed (Section 3.1). (B) Encapsulation for attract-and-kill strategies, where components may be co-encapsulated or separately encapsulated into “attract” (e.g., baker’s yeast and nutrients) and “kill” (EPF and nutrients) beads for co-application. (C) Oil-in-water Pickering emulsion, with a capsule containing a single conidium.