Jason Lee Furuie

The use of two or more microorganisms in a microbial consortium has been increasingly applied in the biological control of diseases and pests.Beauveria bassianais one of the most widely studied fungal species in biological control, yet little is known about its role in fungal consortiums. In a previous study, our group found that a consortium formed by two strains ofB.bassianahad significantly greater biocontrol potential against the polyphagous caterpillarsDuponchelia fovealis(Lepidoptera: Crambidae) than either strain on its own. In this study, we use GC-MS and LC-MS/MS to evaluate and discuss the metabolomics of the consortium. A total of 21 consortium biomarkers were identified, corresponding to 14 detected by LC-MS/MS and seven by GC-MS. Antioxidant and anti-inflammatory mechanisms are the main properties of the metabolites produced by the consortium. These metabolites can depress the insect’s immune system, increasing its vulnerability and, hence, the fungal virulence of the consortium. In light of these results, we propose an action model of insect mortality due to the metabolites secreted by the consortium. The model includes the inhibition of defense mechanisms such as pro-inflammatory interleukin secretion, cell migration, cell aggregation, Dif, Dorsal and Relish gene transcription, and JAK/STAT and JNK signaling pathways. It also promotes the cleaning of oxidative molecules, like ROS, NOS, and H₂O₂, and the induction of virulence factors.

The biological control (BC) is an efficient tool in helping to reduce pests in crops of economic interest. In addition to the efficiency, there are advantages in using biological control agents, such as human safety and other non-target organisms and decreasing pesticide residues. The general aim of this work was to evaluate in vitro the pathogenicity power of fifteen Beauveria bassiana strains aiming the biological control of Drosophila suzukii (Matsumura, 1931). Successful infection of entomopathogenic fungi depends primarily on the adherence and penetration ability of a fungus to the host integuments. In addition, scanning electron microscopy was realized. To verify the spore adherence after the spraying tests, insects were collected throughout the bioassays in order to confirm spore evolution on the insect cuticle. In this work, D. suzukii adults were not susceptible to the aqueous suspensions of conidia at concentrations of 108 spores·mL−1 of these strains. There wasn’t death confirmed by fungus extrusion after maintenance in humid chamber.

Lema bilineata Germar (Coleoptera: Chrysomelidae) was recently reported to damage Physalis peruviana crops in Brazil. Given the potential for inflicting damage on other Solanaceae species and the lack of alternatives for controlling this pest, we assessed the pathogenicity of 15 Beauveria isolates against L. bilineata adults in vitro. In addition, three of these isolates were tested for their ovicidal effect against L. bilineata eggs. Fungal strains were isolated from mummified corpses of L. bilineata collected in a non-commercial field in Paraná, Brazil. The isolates were identified as Beauveria bassiana using molecular markers. Lema bilineata adults were susceptible to conidial suspensions of all these isolates at a concentration of 10⁸ conidia mL⁻¹. Deaths caused by fungal extrusion were confirmed. Three strains were found to be more virulent against L. bilineata adults and showed ovicidal effects. This is the first study on entomopathogenic fungi isolated from dead insects collected from P. peruviana crops and tested against L. bilineata carried out in Brazil. The results obtained in the laboratory indicate the high potential of the use of three B. bassiana strains against L. bilineata as a biocontrol agent.

The use of entomopathogenic microorganisms represents a viable alternative in the management of the Duponchelia fovealis (Lepidoptera: Crambidae). In the present study, we evaluated the mortality of immature stages of D. fovealis caused by entomopathogenic fungi and commercial bioinsecticides. The most virulent strains were Beauveria bassiana 4485 and 4488, leading to mortality rates higher than 80% for the third instar. The mortality rates for these strains were higher than 50% in the first larval stages. However, a reduction to 8.31% and 32% for 4485 and 6.74% and 33% for 4488 was observed in the control of eggs and pupae, respectively. The most pathogenic commercial product was the one based on the HD-1 strain of Bacillus thuringiensis ( Bt ), with a mortality rate higher than 90%. This product decreased the survival rates of D. fovealis larvae more rapidly than B. bassiana strains, with a mean survival time of 85.52 h after seven days of exposure. The initial developmental stages of D. fovealis showed higher lethality, with a mortality rate of 91.75% for the first and 79.79% for the second instar. Our results show that B. bassiana strains 4485 and 4488 and the HD-1 Bt-based product represent a viable management strategy to control D. fovealis , therefore contributing to a more sustainable strawberry production in Brazil.

Increased production of the Cape gooseberry (Physalis peruviana L.) in Brazil has given rise to interest in identifying the phytophagous species that might damage this crop to inform preventive control and integrated pest management strategies. In this study, we report the occurrence and describe the damage that larvae and adults of Lema bilineata Germar (Coleoptera: Chrysomelidae) cause in P. peruviana. The number of L. bilineata individuals, both larvae and adults, significantly affected the total consumption of P. peruviana leaves. We also report, for the first time, three natural enemies, including a fungus, a fly, and an ant, which are associated with this pest in Brazil and may play a role in biological control strategies.

Ochratoxin A (OTA) is a mycotoxin found in several agricultural commodities. Produced by Aspergillus spp., it is nephrotoxic and hepatotoxic and can be carcinogenic. Preventive measures are preventing fungal growth and OTA production. In this study, fungal strains (Rhizopus oryzae, Lichtheimia ramosa, Aspergillus westerdijkiae, Aspergillus niger, Aspergillus tamarii, Aspergillus sp., and Aspergillus fumigatus) isolated from coffee beans were identified for their abilities to inhibit the growth of Aspergillus ochraceus, Aspergillus westerdijkiae, Aspergillus carbonarius, and Aspergillus niger, and OTA production. All fungi strains tested were able to inhibit growth of the four Aspergillus species and OTA production, where A. niger showed the best results in both tests. L. ramosa showed the lowest growth-reducing potential, while the other fungal strains had a growth-reducing potential higher than 70% against all Aspergillus species tested. Regarding OTA production, L. ramosa and Aspergillus sp. completely inhibited the mycotoxin production by A. ochraceus and non-toxigenic strain A. niger completely inhibited OTA production by A. niger. Our findings indicate that the strains tested can be used as an alternative means to control growth of OTA-producing fungi and production of the mycotoxin in coffee beans.