Evaluation of the Entomopathogenic Potential of Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea for Management of Cosmopolites sordidus Germar (Coleoptera: Curculionidae)

The banana weevil (BW), Cosmopolites sordidus, is the main coleopteran pest of banana, causing up to 100% yield loss. In this study, we screened 20 isolates of entomopathogenic fungi (EPF) for the management of BW. In the lab, eight Beauveria bassiana isolates caused >50% mortality of the adult BW, whereas Metarhizium anisopliae and Isaria fumosorosea isolates were less pathogenic. B. bassiana isolates ICIPE 648, ICIPE 660 and ICIPE 273 were the most pathogenic, killing ≥80% of adult BW. B. bassiana isolate ICIPE 622 yielded the highest spores per BW cadaver (1.84 × 108 spores), followed by ICIPE 660, ICIPE 273 and ICIPE 648—1.17 × 108, 3.8 × 107 and 3.6 × 107 spores, respectively. ICIPE 273 had the shortest LT50 (5.3 days) followed by ICIPE 648 (9.8 days) and 660 (11.1 days). Similarly, the LC50 values for the three isolates were 5.18 × 107, 5.49 × 107 and 5.2 × 107 spores mL−1, respectively. In the field, ICIPE 273 and ICIPE 648 had the highest (31.3%) and lowest (20.8%) pathogenicity, respectively. This study indicates that the B. bassiana isolates ICIPE 273, ICIPE 648 and ICIPE 660 are potential candidates for the environmentally sustainable management of BW.

Антагонистическая активность энтомопатогенных грибов в отношении фитопатогенных микромицетов

The researches on evaluation the influence of entomopathogenic fungi of the genuses Beauveria, Isaria and Lecanicillium influence on phytopathogenic microorganisms Alternaria solani, Botrytis ciner-ea, Sclerotinia sclerotiorum, Rhizoctonia solani, Fusarium solani, Phytophtora alni are presented. The antifungal peculiarities of tested strains – a potential basis of complex action biological preparations for plant protection are shown in vitro. The highest level of antagonistic activity has been revealed in strains Beauveria brongniartii МХ, Lecanicillium sp. аph and Isaria fumosorosea 21-2.

New Glycosylated Dihydrochalcones Obtained by Biotransformation of 2′-Hydroxy-2-methylchalcone in Cultures of Entomopathogenic Filamentous Fungi

Flavonoids, including chalcones, are more stable and bioavailable in the form of glycosylated and methylated derivatives. The combined chemical and biotechnological methods can be applied to obtain such compounds. In the present study, 2′-hydroxy-2-methylchalcone was synthesized and biotransformed in the cultures of entomopathogenic filamentous fungi Beauveria bassiana KCH J1.5, Isaria fumosorosea KCH J2 and Isaria farinosa KCH J2.6, which have been known for their extensive enzymatic system and ability to perform glycosylation of flavonoids. As a result, five new glycosylated dihydrochalcones were obtained. Biotransformation of 2′-hydroxy-2-methylchalcone by B. bassiana KCH J1.5 resulted in four glycosylated dihydrochalcones: 2′-hydroxy-2-methyldihydrochalcone 3′-O-β-d-(4″-O-methyl)-glucopyranoside, 2′,3-dihydroxy-2-methyldihydrochalcone 3′-O-β-d-(4″-O-methyl)-glucopyranoside, 2′-hydroxy-2-hydroxymethyldihydrochalcone 3′-O-β-d-(4″-O-methyl)-glucopyranoside, and 2′,4-dihydroxy-2-methyldihydrochalcone 3′-O-β-d-(4″-O-methyl)-glucopyranoside. In the culture of I. fumosorosea KCH J2 only one product was formed—3-hydroxy-2-methyldihydrochalcone 2′-O-β-d-(4″-O-methyl)-glucopyranoside. Biotransformation performed by I. farinosa KCH J2.6 resulted in the formation of two products: 2′-hydroxy-2-methyldihydrochalcone 3′-O-β-d-(4″-O-methyl)-glucopyranoside and 2′,3-dihydroxy-2-methyldihydrochalcone 3′-O-β-d-(4″-O-methyl)-glucopyranoside. The structures of all obtained products were established based on the NMR spectroscopy. All products mentioned above may be used in further studies as potentially bioactive compounds with improved stability and bioavailability. These compounds can be considered as flavor enhancers and potential sweeteners.

Fungal Biotransformation of 2′-Methylflavanone and 2′-Methylflavone as a Method to Obtain Glycosylated Derivatives

Methylated flavonoids are promising pharmaceutical agents due to their improved metabolic stability and increased activity compared to unmethylated forms. The biotransformation in cultures of entomopathogenic filamentous fungi is a valuable method to obtain glycosylated flavones and flavanones with increased aqueous solubility and bioavailability. In the present study, we combined chemical synthesis and biotransformation to obtain methylated and glycosylated flavonoid derivatives. In the first step, we synthesized 2′-methylflavanone and 2′-methylflavone. Afterwards, both compounds were biotransformed in the cultures of two strains of entomopathogenic filamentous fungi Beauveria bassiana KCH J1.5 and Isaria fumosorosea KCH J2. We determined the structures of biotransformation products based on NMR spectroscopy. Biotransformations of 2′-methyflavanone in the culture of B. bassiana KCH J1.5 resulted in three glycosylated flavanones: 2′-methylflavanone 6-O-β-d-(4″-O-methyl)-glucopyranoside, 3′-hydroxy-2′-methylflavanone 6-O-β-d-(4″-O-methyl)-glucopyranoside, and 2-(2′-methylphenyl)-chromane 4-O-β-d-(4″-O-methyl)-glucopyranoside, whereas in the culture of I. fumosorosea KCH J2, two other products were obtained: 2′-methylflavanone 3′-O-β-d-(4″-O-methyl)-glucopyranoside and 2-methylbenzoic acid 4-O-β-d-(4′-O-methyl)-glucopyranoside. 2′-Methylflavone was effectively biotransformed only by I. fumosorosea KCH J2 into three derivatives: 2′-methylflavone 3′-O-β-d-(4″-O-methyl)-glucopyranoside, 2′-methylflavone 4′-O-β-d-(4″-O-methyl)-glucopyranoside, and 2′-methylflavone 5′-O-β-d-(4″-O-methyl)-glucopyranoside. All obtained glycosylated flavonoids have not been described in the literature until now and need further research on their biological activity and pharmacological efficacy as potential drugs.

Response of Entomopathogenic Fungus Paecilomyces fumosoroseus on Drought Stress Factor

The entomopathogenic fungus Paecilomyces fumosoroseus (common name: Isaria fumosorosea) can utilize to control white fly population. Bemisia tabaci or white fly has become key pest in soybean cultivation. It reported became resistance due to chemical pesticide. Some of new strain has been emerge as chemical pesticide resultant However, to develop P. fumosoroseus as biopesticide hide a problem. The environmental drought factor (temperature and water stress) become major problem. This research aimed to determine effect of environmental factor like temperature and water stress to growth and effectivity of P. fumosoroseus, due to selection an isolat were persist to drought factor. In this research has been used two different isolat of P. fumosoroseus, that is Wirowongso 1 isolat and Mumbulsari 5 isolates. This research had been conducted with five different treatments. First is a growth test under temperature stress, in vitro germination test under temperature stress and in vitro germination test under water stress, and virulence test under temperature and under water stress. The result showed that the increase a temperature and of water stress, directly make decreased of growth, germination and effectively. That effect has made different effect to growth, germination and effectivity on both isolat. The results showed that the isolat WR 1 test result showed the isolat WR 1 more persist to each drought factor. It became more valuable to develop as biopesticide among other.Keywords: Bemicia tabaci, germination, isolat, Isaria fumosorosea, in-vivo.

Impact of Metarhizium robertsii on Adults of the Parasitoid Diachasmimorpha longicaudata and Parasitized Anastrepha ludens Larvae

Biological control of the Mexican fruit fly, Anastrepha ludens, is mainly carried out by releasing parasitoids, such as Diachasmimorpha longicaudata, and by applying entomopathogenic fungi (EPF), such as Metarhizium anisopliae, Beauveria bassiana, or Isaria fumosorosea, which can be applied to the soil or dispersed using infective devices. The combined use of two or more biocontrol agents could improve A. ludens control, but IGP between natural enemies, if it occurs, may have negative effects. We evaluated the effects of EPF on D. longicaudata. First, we determined the susceptibility of adults of D. longicaudata to strains of EPF (Metarhizium robertsii strain V3-160 and M. anisopliae strain MAAP1). We also evaluated the infection of these two fungi on A. ludens larvae parasitized by D. longicaudata. Finally, we determined sub-lethal effects on adults of D. longicaudata that emerged from larvae that had been exposed to low concentrations of M. robertsii. Both fungi caused moderate mortality to D. longicaudata adults. There were no adverse effects on the longevity of parasitoids that emerged from parasitized larvae exposed to M. robertsii. Based on these results, we argue that M. robertsii has the potential to be used for biocontrol of A. ludens, with limited risk to D. longicaudata adults.

Entomopathogenic nematodes and fungi to control Hyalesthes obsoletus (Hemiptera: Auchenorrhyncha: Cixiidae)

Hyalesthes obsoletus Signoret (Hemiptera: Auchenorrhyncha: Cixiidae) is a univoltine, polyphagous planthopper that completes its life cycle, including the subterranean nymph cryptic stage, on herbaceous weeds. In vineyards, it can transmit ‘Candidatus Phytoplasma solani’, an obligate parasitic bacterium associated with bois noir (BN) disease of grapevine, from its host plants to grapevine when occasionally feeding on the latter. The main disease management strategies are based on vector(s) control. Insecticide treatments on grapevine canopy are completely inefficient on H. obsoletus, due to its life cycle. Consequently, control of this planthopper focuses on the nymphs living on the roots of their host plants. Such practices, based on herbicide application and/or weed management, can reduce vector density in the vineyard but can impact the environment or may not be applicable, highlighting the necessity for alternative strategies. In this study, the efficacy of entomopathogenic nematodes (EPNs; Steinernema carpocapsae, S. feltiae, Heterorhabditis bacteriophora) and fungi (EPFs; Beauveria bassiana, Metarhizium anisopliae, Isaria fumosorosea, Lecanicillium muscarium) against H. obsoletus nymphs (EPNs) and adults (EPNs and EPFs) was assessed under laboratory and greenhouse conditions. The majority of examined EPNs and EPFs were able to kill H. obsoletus exhibiting a range of effectiveness. S. carpocapsae (among EPNs) and I. fumosorosea (among EPFs) were found to be the most effective biocontrol agents in all trials carried out. Advantages and limitations of such promising biocontrol agents were discussed. Ecological competency and conditions that can impede or enhance the EPNs and EPFs performance should be investigated to optimize their performance under field conditions.