Application of the Spores of the Entomopathogenic Fungus Lecanicillium Muscarium for Control of Adelgids on Conifers in the Peter the Great Botanical Garden

This article discusses the possibility of using the entomopathogenic fungus Lecanicillium muscarium R. Zare & W. Gams (Ascomycota: Hypocreales) against the fir adelgid Adelges pectinatae pectinatae (Cholodkovsky, 1888) and Siberian cedar adelgid Pineus cembrae (Cholodkovsky, 1888) on the Siberian fir Abies sibirica Ledeb., and pines Pinus sibirica Du Tour and Pinus banksiana Lamb. The blastospores of the entomopathogenic fungus L. muscarium strain G-033 VIZR, in the concentration of 5x107 spores/ml, showed a high efficiency on both of the species of adelgid. On the 17th day, the mortality of P. cembrae was 73% on P. sibirica and 61% on P. banksiana, and the mortality of the species A. pectinatae pectinatae on A. sibirica was 74%. The effect of the spore application had a prolonged effect over the next month on all treated trees. Keywords: entomopathogenic fungi, Lecanicillium muscarium, adelgid, conifers

Symbiont-Mediated Protection of Acromyrmex Leaf-Cutter Ants from the Entomopathogenic Fungus Metarhizium anisopliae

In some plants and animals, beneficial microbes mediate host immune response against pathogens, including by serving as defensive symbionts that produce antimicrobial compounds. Defensive symbionts are known in several insects, including some leaf-cutter ants where antifungal-producing Actinobacteria help protect the fungal mutualist of the ants from specialized mycoparasites.

Season-long infection of diverse hosts by the entomopathogenic fungus Batkoa major

Populations of the entomopathogenic fungus Batkoa major were analyzed using sequences of four genomic regions and evaluated in relation to their genetic diversity, insect hosts and collection site. This entomophthoralean pathogen killed numerous insect species from 23 families and five orders in two remote locations during 2019. The host list of this biotrophic pathogen contains flies, true bugs, butterflies and moths, beetles, and barkflies. Among the infected bugs (Order Hemiptera), the spotted lanternfly ( Lycorma delicatula ) is a new invasive planthopper pest of various woody plants that was introduced to the USA from Eastern Asia. A high degree of clonality occurred in the studied populations and high gene flow was revealed using four molecular loci for the analysis of population structure. We did not detect any segregation in the population regarding host affiliation (by family or order), or collection site. This is the first description of population structure of a biotrophic fungus-generalist in the entomopathogenic Order Entomophthorales. This analysis aimed to better understand the potential populations of entomopathogen-generalists infecting emerging invasive hosts in new ecosystems.

Biological control of gypsy moth (Lymantria dispar) by the entomopathogenic fungus Entomophaga maimaiga in Bulgaria in 2021

In 2021, biological control programme against gipsy moth (Lymantria dispar) populations was carried out by introduction of the entomopathogenic fungus Entomophaga maimaiga on the territory of four State Forest Enterprises: Municipal Enterprise (ME) ‘Management of Municipal Forests, Agriculture and Forestry’, Nessebar; State Game Enterprises (SGE) Nessebar and Balchik; State Forestry (SF) Vidin. The pathogen was introduced during the period 15-26.03.2021 in 34 localities - five in ME Nessebar, eight in SGE Nessebar, ten in SGE Balchik and eleven in SF Vidin. The average number of gypsy moth population density in the locations of introduction was relatively high, ranging between 0.4-15.9 egg mass/tree in the area of ​​SGE Balchik and 11.9-65.0 egg mass/tree in the area of ​​ME Nessebar. The average mortality of young gypsy moth caterpillars (first-third instar) due to E. maimaiga varied between 2.6% (SGE Balchik) and 13.0% (SF Vidin), and of caterpillars in later fourth-sixth instar - between 20.7% (SF Vidin) and 52.4% (ME Nessebar). The overall mortality of the gipsy moth caterpillars due to E. maimaiga was lowest in the region of SGE Balchik (26.1%), followed by SF Vidin (33.7%), SGE Nessebar (48.5%) and ME Nessebar (55.9%). As a result of the introduction, gipsy moth severe outbreaks in the region of Nessebar was significantly suppressed. The high number of E. maimaiga resting spores persists in the surface layers of the soil in the other two areas (Vidin and Balchik) has the potential to suppress L. dispar attacks in next years.

Influence of the composition of nutrient media on the productivity and biological activity of the strain of entomopathogenic fungus Beauveria bassiana

The productivity and biological activity of the entomopathogenic fungus Beauveria bassiana (F-145) strain during the liquid-phase cultivation on various substrates for developing a biopesticide in its native form was analyzed (the research was carried out in 2019). For submerged cultivation, by-products from dairy and beer production (milk whey and brewing spent grain liquor) were used as components of the nutrient medium with addition of diesel fuel (DF) and Tween-80 as inducers of biological activity. It has been established, that the productivity of the strain on industrial by-product substrates was 1.5-2 times higher than on the Czapek medium. A high yield of a mycelial biomass with a titer of 108 -1010 CFU/ml was shown in a 5-day suspension based on a mixture of milk whey and brewing spent grain liquor. The biological activity of the culture suspension of the strain was determined. It was shown that the nematicidal activity of Beauveria bassiana strain with regard to nematodes of the Rhabditis sp. was largely manifested in a suspension obtained on a mixed medium with the addition of inducers. Ninety per cent death at mobile nematode stages was registered within one or two days of test-organism incubation. A complex nutrient medium composition containing by-products and inducers contributed to the preservation of the biological activity of the strain. The strain nematicidal activity was established at the level of 67-80 per cent with a titer of 106 -107 CFU/ml when the suspension was stored for 67 days.

Differential Responses of Ceratitis Capitata to Infection by the Entomopathogenic Fungus Purpureocillium Lilacinum.

Ceratitis capitata (medfly), is one of the most injurious pests of fruits with quarantine importance because of its extremely wide host range. The use of entomopathogenic fungi constitutes a promising approach for potential applications in integrated pest management. Nonetheless, developing methods of insect control can also involve the use of fungal machinery to produce metabolic disturbance that can increase its effectiveness by producing a detrimental effect on insect development. Insect species, such as Ceratitis capitata, depend on reproduction potential, nutrient reserves, metabolic activities and immune response for their survival. Accordingly, the purpose of this study is to use the entomopathogenic fungus Purpureocillium lilacinum to investigate, its sublethal effects on Ceratitis capitata. Laboratory bioassays were conducted on medfly V8 strain. The bioassays were monitored to determine the virulence of P. lilacinum on the fruit fly. P. lilacinum was tested against 5 days-old males and females, through abdominal topical applications. Following the fungal inoculation, we showed (i) a significant increase of sugar amount in tissues, (ii) a significant decrease in carbohydrase activities, digestive glycosyl hydrolase and proteinase activities in whole midguts of treated flies, (iii) an over-expression of Takeout and Attacin-A genes induced by infection. Moreover, the up-regulations observed for relish, cecropin 1, ceratotox-A and defensin genes are due to physiological mechanisms occurring during infection.