Multifaceted and Other Insect-Related Fungi.

Since Agostino Bassi first isolated the fungal pathogenic agent of the white muscardine in insects (later named in his honor), and Ilya Mechnikov cultivated as a first approach to use fungi as pest control agents, many other entomopathogenic fungi have been studied over the last two centuries [...

and Mix Suppresses Rhizoctonia Disease and Improves Rhizosphere Microbiome, Growth and Yield of Potato ( L.).

Black scurf and stem canker caused by is a significant disease problem of potatoes. Currently, chemical methods are the primary means of controlling this pathogen. This study sought to explore an alternative approach by harnessing the biocontrol potential of a bacterial mix of and against black scurf, and to determine their effect on rhizosphere microorganisms of soil microbiota.

Entomopathogenic Fungi in Biological Plant Protection: The Machinery of Multicomponent System Interactions.

Plant protection faces a growing number of challenges, partly stemming from intensification of plant cultivation to ensure food security for a rapidly growing global population [...

Virulent and necrotrophic strategies of Bacillus thuringiensis in susceptible and resistant insects, Galleria mellonella.

Bacillus thuringiensis (Bt) is one of the most common entomopathogenic bacteria used as a biopesticide, and source of endotoxin genes for generating insect-resistant transgenic plants. The mechanisms underpinning an insect's susceptibility or resistance to B. thuringiensis are diverse.

Polygenic adaptation contributes to the invasive success of the Colorado potato beetle.

How invasive species cope with novel selective pressures with limited genetic variation is a fundamental question in molecular ecology. Several mechanisms have been proposed, but they can lack generality. Here, we addressed an alternative solution, polygenic adaptation, wherein traits that arise from multiple combinations of loci may be less sensitive to loss of variation during invasion.

The Effect of Silicon Dioxide Nanoparticles Combined with Entomopathogenic Bacteria or Fungus on the Survival of Colorado Potato Beetle and Cabbage Beetles.

Three types of modified silicon dioxide nanoparticles (SiO2, 10−20 nm) with additives of epoxy, silane and amino groups, used independently and in combination with the entomopathogenic bacteria Bacillus thuringiensis subsp. morrisoni and fungus Metarhizium robertsii were tested against Colorado potato beetle (Leptinotarsa decemlineata) and cabbage beetles (Phyllotreta spp.).

Spores and Cry3A Toxins Act Synergistically to Expedite Colorado Potato Beetle Mortality.

The insect integument (exoskeleton) is an effective physiochemical barrier that limits disease-causing agents to a few portals of entry, including the gastrointestinal and reproductive tracts. The bacterial biopesticide (Bt) enters the insect host via the mouth and must thwart gut-based defences to make its way into the body cavity (haemocoel) and establish infection. We sought to uncover the main antibacterial defences of the midgut and the pathophysiological features of Bt in a notable insect pest, the Colorado potato beetle (CPB).

RNAi-mediated suppression of insect metalloprotease inhibitor (IMPI) enhances Galleria mellonella susceptibility to fungal infection.

The co-evolutionary arms race between disease-causing agents and their insect victims is ancient and complex - leading to the development of specialised attack and defence strategies. Among such strategies is the capacity of fungal and oomycete pathogens to deploy degradative enzymes, notably proteases, to facilitate infection directly across the integument. To counter these proteases, insects such as the greater wax moth Galleria mellonella release metalloprotease inhibitors and other immune factors to thwart the invading fungus.

Host-Pathogen Interactions: Insects vs. Fungi.

Although many insects successfully live in dangerous environments exposed to diverse communities of microbes, they are often exploited and killed by specialist pathogens [...

Effect of Juvenile Hormone on Resistance against Entomopathogenic Fungus Differs between Sexes.

Juvenile hormone has been suggested to be a potential mediator in the trade-off between mating and insects' immunity. Studies on various insect taxons have found that juvenile hormone interferes with humoral and cellular immunity. Although this was shown experimentally, studies using highly virulent parasites or pathogens are lacking so far.

infection dynamics differ at the cuticle interface of susceptible and tolerant morphs of .

In order for entomopathogenic fungi to colonize an insect host, they must first attach to, and penetrate, the cuticle layers of the integument. Herein, we explored the interactions between the fungal pathogen ARSEF 4556 and two immunologically distinct morphs, melanic (M) and non-melanic (NM), of the greater wax moth . We first interrogated the cuticular compositions of both insect morphs to reveal substantial differences in their physiochemical properties.

Greater wax moth Galleria mellonella (Lepidoptera: Pyralidae) as a resistant model host for Nosema pyrausta (Microsporidia: Nosematidae).

Galleria mellonella fed 3 million Nosema pyrausta spores per larva showed 0 and 5% infestation rate at 30 °C and 24 °C, respectively. N. pyrausta virulence did not increase after passage through G.

Maintenance of redox balance by antioxidants in hemolymph of the greater wax moth Galleria mellonella larvae during encapsulation response.

The lipid peroxidation process in hemocytes, activities of phenoloxidase and key enzymatic antioxidants (superoxide dismutase, glutathione-S-transferase, catalase) and nonenzymatic antioxidants (thiols, ascorbate) in hemolymph of the greater wax moth Galleria mellonella L. (Lepidoptera: Pyralidae) were studied during the encapsulation process of nylon implants. It has been established that as soon as 15 min after piercing a cuticle with the implant, a capsule is formed on its surface.

Bacterial and fungal infections induce bursts of dopamine in the haemolymph of the Colorado potato beetle Leptinotarsa decemlineata and greater wax moth Galleria mellonella.

Dopamine (DA) is known as a hormone neurotrasnmitter molecule involved in several stress reactions in both vertebrates and invertebrates. Following infections with the fungi Metarhizium robertsii or Beauveria bassiana and the bacterium Bacillus thuringiensis, dopamine the concentration was measured at different time points in the haemolymph of the Colorado potato beetle, Leptinotarsa decemlineata and the larvae of the greater wax moth Galleria mellonella. The infection with M.

The activity of phenoloxidase in haemolymph plasma is not a predictor of Lymantria dispar resistance to its baculovirus.

Host innate immunity is one of the factors that determines the resistance of insects to their entomopathogens. In the research reported here we studied whether or not phenoloxidase (PO), a key enzyme in the melanogenesis component of humoral immunity of insects, plays a role in the protection of Lymantria dispar larvae from infection by L. dispar multiple nucleopolyhedrovirus.

Phenological asynchrony between host plant and gypsy moth reduces insect gut microbiota and susceptibility to .

The phenological synchrony between the emergence of overwintering herbivorous insects and the budding of host plants is considered a crucial factor in the population dynamics of herbivores. However, the mechanisms driving the interactions between the host plant, herbivores, and their pathogens are often obscure. In the current study, an artificially induced phenological asynchrony was used to investigate how the asynchrony between silver birch and gypsy moth affects the immunity of the insect to bacteria, its susceptibility to the entomopathogenic bacteria , and the diversity in its midgut microbiota.

Fungal infection dynamics in response to temperature in the lepidopteran insect Galleria mellonella.

This study examines how the dynamics of fungus-insect interactions can be modulated by temperature. The wax moth, Galleria mellonella, is a well-studied and important model insect whose larvae in the wild develop optimally at around 34 °C in beehives. However, surprisingly little research on wax moths has been conducted at relevant temperatures.

Immunological mechanisms of synergy between fungus Metarhizium robertsii and bacteria Bacillus thuringiensis ssp. morrisoni on Colorado potato beetle larvae.

The synergistic effect between the entomopathogenic fungus Metarhizium robertsii and a sublethal dose of the bacterium Bacillus thuringiensis ssp. morrisoni var. tenebrionis was studied in terms of immune defense reactions and detoxification system activity of the Colorado potato beetle, Leptinotarsa decemlineata, fourth instar larvae.

Immune-physiological aspects of synergy between avermectins and the entomopathogenic fungus Metarhizium robertsii in Colorado potato beetle larvae.

The interaction between the entomopathogenic fungus Metarhizium robertsii and natural avermectin metabolites of the actinomycete Streptomyces avermitilis were investigated on Colorado potato beetle larvae. A synergy in the mortality of larvae was detected after simultaneous treatment with half-lethal doses of avermectins (commercial name actarophit) 0.005% and fungus (5×10conidia/ml).

Immuno-physiological adaptations confer wax moth Galleria mellonella resistance to Bacillus thuringiensis.

Microevolutionary mechanisms of resistance to a bacterial pathogen were explored in a population of the Greater wax moth, Galleria mellonella, selected for an 8.8-fold increased resistance against the entomopathogenic bacterium Bacillus thuringiensis (Bt) compared with a non-selected (suspectible) line. Defense strategies of the resistant and susceptible insect lines were compared to uncover mechanisms underpinning resistance, and the possible cost of those survival strategies.

Asynchrony between Host Plant and Insects-Defoliator within a Tritrophic System: The Role of Herbivore Innate Immunity.

The effects of asynchrony in the phenology of spring-feeding insect-defoliators and their host plants on insects' fitness, as well as the importance of this effect for the population dynamics of outbreaking species of insects, is a widespread and well-documented phenomenon. However, the spreading of this phenomenon through the food chain, and especially those mechanisms operating this spreading, are still unclear. In this paper, we study the effect of seasonally declined leafquality (estimated in terms of phenolics and nitrogen content) on herbivore fitness, immune parameters and resistance against pathogen by using the silver birch Betula pendula--gypsy moth Lymantria dispar--nucleopolyhedrovirus as the tritrophic system.

Leaf surface lipophilic compounds as one of the factors of silver birch chemical defense against larvae of gypsy moth.

Plant chemical defense against herbivores is a complex process which involves a number of secondary compounds. It is known that the concentration of leaf surface lipophilic compounds (SLCs), particularly those of flavonoid aglycones are increased with the defoliation treatment of silver birch Betula pendula. In this study we investigated how the alteration of SLCs concentration in the food affects the fitness and innate immunity of the gypsy moth Lymantria dispar.

Can insects develop resistance to insect pathogenic fungi?

Microevolutionary adaptations and mechanisms of fungal pathogen resistance were explored in a melanic population of the Greater wax moth, Galleria mellonella. Under constant selective pressure from the insect pathogenic fungus Beauveria bassiana, 25(th) generation larvae exhibited significantly enhanced resistance, which was specific to this pathogen and not to another insect pathogenic fungus, Metarhizium anisopliae. Defense and stress management strategies of selected (resistant) and non-selected (susceptible) insect lines were compared to uncover mechanisms underpinning resistance, and the possible cost of those survival strategies.

The effects of defoliation-induced delayed changes in silver birch foliar chemistry on gypsy moth fitness, immune response, and resistance to baculovirus infection.

We tested the effects of defoliation-induced changes in silver birch, Betula pendula, foliar chemistry (delayed induced resistance, DIR) on the fitness and immune defense of the gypsy moth, Lymantria dispar. We measured larval developmental time, pupal weight, rate of survival to the adult stage, and five characteristics of larval immune defense: (1) encapsulation response; (2) phenoloxidase activity; (3) hemocyte concentration and (4) lysozyme-like activity in the hemolymph; and (5) resistance to infection by L. dispar nucleopolyhedrovirus (LdMNPV).