Entomopathogenic fungi are a special group of soil-dwelling microorganisms that infects and kills insects and other arthropods through cuticle penetration. They are currently used as biocontrol agents against insect plant pests and play a vital role in their management. Regardless that entomopathogenic fungi are currently on the agriculture market, their full potential has not yet been utterly explored. Up to date substantial research has covered the topic revealing numerous uses in pest management but also on their ability as endophytes, assisting the plant host on growth and pathogen resistance. This article addresses the literature on entomopathogenic fungi through the years, noting their mode of action, advantages, potential applications, and prospects.

Entomopathogenic fungi (EPF) can colonize plant tissues and serve crops not only as biopesticides but also as biostimulants that promote plant growth and trigger defense mechanisms. In this context, field trials were conducted evaluating two commercial strains of the entomopathogen Beauveria bassiana (Hypocreales: Cordycipitaceae), GHA (Botanigard) and PPRI 5339 (Velifer^® ES) and a wild strain (AP0101) isolated from Achaia, Greece. The three strains were investigated in the field for their endophytic effects on melon Cucumis melo (Cucurbitales: Cucurbitaceae) and strawberry Fragaria sp. (Rosales: Rosaceae) plants and in particular for their ability to colonize plant tissues, control infestations of sucking insects Aphis gossypii (Hemiptera: Aphididae), Chaetosiphon fragaefolii (Hemiptera: Aphididae) and Frankliniella occidentalis (Thysanoptera: Thripidae), and improve plant growth parameters (plant height, number of flowers and fruits). All experimental fungal strains successfully colonized both plants. A significant decrease in the aphid and thrip populations was observed in the treated plants compared to the untreated control. As for plant growth, the number of flowers and fruits was significantly increased in plants treated with B. bassiana strains AP0101 and PPRI 5339. Our results clearly indicate that fungal endophytes can efficiently act as dual action agents demonstrating both insecticidal and growth-promoting effects.

The integration of semi-transparent photovoltaics into the roof of greenhouses is an emerging technique used in recent years, due to the simultaneous energy and food production from the same piece of land. Although shading in many cases is a solution to maintain the desired microclimate, in the case of photovoltaic installations, the permanent shading of the crop is a challenge, due to the importance of light to the growth, morphogenesis, and other critical physiological processes. In this study, the effect of shade from semi-transparent photovoltaics on a strawberry crop (Fragaria x ananassa Duch.) was examined, in terms of growth and quality (phenolic and flavonoid concentration of fruits). According to the results, in non-shaded plants, there was a trend of larger plants, but without a significant change in leaf number, while the total number of flowers was slightly higher at the end of the cultivation period. Moreover, it was found that the percentage change between the number of ripe fruits was smaller than that of the corresponding change in fruit weight, implying the increased size of the fruits in non-shaded plants. Finally, regarding the antioxidant capacity, it was clearly demonstrated that shading increased the total phenolic content, as well as the free-radical-scavenging activity of the harvested fruits. Although the shading from the semi-transparent photovoltaics did not assist the production of large fruits, it did not affect their number and increased some of their quality characteristics. In addition, the advantageous impact of the semi-transparent photovoltaics in the energy part must not be neglected.

There is ample evidence that entomopathogenic fungi can be used as alternative biological control agents for the management of insect pests in storage facilities. As the market demands more environmentally friendly methods and chemical insecticides become increasingly obsolete, more studies are being conducted to evaluate new strains of entomopathogenic fungi for their efficacy in storage facilities. In this context, we tested ten species of fungi isolated from soil, belonging to the genera Cladosporium, Condenascus, Lecanicillium, and Penicillium, for their long-term effects on economically important beetle species. Whole wheat was directly sprayed with a conidial suspension of 10⁸ spores/Ml of each of the tested fungi and then adults of Sitophilus granarius, S. oryzae, S. zeamais, Rhyzopertha dominica, and Trogoderma granarium were placed on the sprayed medium to study the mortality effects. Significantly higher mortality than the control was observed in all treatments. The lowest LT₅₀ (9.164 days) was observed in T. granarium infected with Penicillium goetzii. The isolate with the strongest results was L. dimorphum, which recorded remarkably low LT₅₀ values in S. oryzae (~11 days), R. dominica (~12 days), T. granarium (~10 days), and S. granarius (~13 days). However, for S. zeamais, it was more than 16 days. Our results confirm the existing literature on the efficacy of EPF on storage beetles, suggest the possible virulence of wild untested strains, and also highlight the importance of EPF specificity.

The cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a notorious agricultural pest with world-wide distribution, extreme polyphagy, high mobility and fecundity, facultative diapause, and significant resistance to chemical insecticides. Isolates from various Fusarium species were collected from soil, identified, and tested for their entomopathogenicity against H. armigera larvae in field experiments. Fungi of the genus Fusarium are ubiquitous and include phytopathogenic as well as entomopathogenic strains. Seven Fusarium species were identified and tested, including: F. algeriense, F. chlamydosporum var. chlamydosporum, F. fujikuroi, F. longifundum, F. pseudoanthophilum, F.solani, and F. tonkinense. All the collected fungi demonstrated a notable insecticidal effect on H. armigera larvae in field conditions, while some proved to be significantly lethal. The larval mortality of H. armigera ranged from 10 (10³ conidia/mL) to 91% (10⁸ conidia/mL) after 9 days (216 h). Larval survival time in treated plants ranged from 95 h (10⁸ conidia/mL) to 208 h (10³ conidia/mL). According to our results, F. solani isolate displayed the highest toxicity against H. armigera larvae and could be considered as a promising biocontrol agent of this serious pest.

Infestations of stored-product pests cause significant losses of agricultural produce every year. Despite various environmental and health risks, chemical insecticides are now a ready-to-use solution for pest control. Against this background and in the context of Integrated Pest Management research, the present study focuses on the potential insecticidal effect of caffeic acid at five different concentrations (250, 500, 750, 1500 and 3000 ppm), and their combination with Cydia pomonella Granulovirus (CpGV), Bacillus thuringiensis subsp. tenebrionis and Beauveria bassiana strain GHA on three major insect stored-product beetle species, Tribolium confusum (Coleoptera: Tenebrionidae), Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) and Trogoderma granarium Everts (Coleoptera: Dermestidae). Treatment efficacy was expressed as mortality in relation to exposure time and adult species number. Compared to the control, the results showed a clear dose-dependent pesticidal activity, expressed as significant adult mortality at a high-dose application, although some of the combinations of caffeic acid concentrations with the other substances acted positively (synergistically and additively) and some negatively. Based on our results, bioinsecticides can be combined with plant compounds such as caffeic acid and be integrated with other modern IPM tools in storage facilities.