Formulations Of Entomopathogenic Fungi Research Articles

Laboratory evaluation of 15 entomopathogenic fungal spore formulations on the mortality of Drosophila suzukii (Diptera: Drosophilidae), related drosophilids, and honeybees

Abstract The drosophilids Drosophila suzukii (Matsumura), Drosophila melanogaster Meigen and Zaprionus indianus Gupta (Diptera: Drosophilidae), are common pests of Mexican berry plantations. Attract-and-infect-based application strategies using entomopathogenic fungi (EPF), which are more environmentally friendly than synthetic chemical pesticides, are currently under evaluation for their potential at controlling insect pests, as compared to synthetic pesticides. In this study, we evaluated 15 EPF formulations against D. suzukii adults to determine which formulations would work best in an attract-and-infect device in terms of spore accumulation, pathogenicity, and mortality. Formulations of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae), Cordyceps javanica (Friederichs & Bally) (Hypocreales: Cordycipitaceae), and Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) spores exhibited the highest levels of conidia attachment, pathogenicity, and virulence, making them effective against D. suzukii. In a subsequent experiment, these formulations were evaluated against D. melanogaster, Z. indianus, and the honey bee, Apis mellifera L. (Hymenoptera: Apidae). Our results revealed that the formulations containing C. javanica and M. anisopliae were highly virulent not only against D. suzukii, but also against D. melanogaster and Z. indianus, with minimal impact on honey bees. Our results showed that spore formulations of M. anisopliae and C. javanica were the most promising entomopathogens for further testing of attract-and-infect devices to manage D. suzukii, D. melanogaster and Z. indianus in berry crops.

Entomopathogenic fungi and their relevance in sustainable agriculture: A review

The use of entomopathogenic fungi (EPF) like Beauveria, Metarhizium, Lecanicillium, and Isaria is upsurging in recent years for the management of crop insect pests. EPF are considered better than synthetic insecticides as they are safe for humans, sustainable to the environment, and target-specific in nature. Many of these EPF are pathogenic to economically important insect pests and thus are capable of controlling them. They are cheaper in long run, show lesser residual effects, and are able to overcome the problem of resistance. EPF degrades the host cuticle and proliferates in hemolymph as hyphal bodies, secreting the toxins responsible for the death of host insects. The later saprophytic growth leads to the production of fungal spores capable of reinfecting other hosts. Different commercial formulations of EPF are available globally such as liquid formulation, wettable powder, suspensible granules, and so on. These available formulations under different trade names can be used for several crops and pests at the recommended dosage to obtain optimum results. The storage conditions should be maintained to retain the viability of EPF. Modern biotechnological interventions could be vital in enhancing the efficacy of these entomopathogens by manipulating their traits. Specialized researches are necessary to understand the interaction between EPF, host insects, crops, and their environment in order to explore the best formulation of mycoinsecticides. This review explores the overview of EPF, its mode of action, significance, commercial formulations, future prospects, and the summary of recent findings. Readers could realize the essence of EPF in sustainable agriculture through this review.

Comparative Study of The Efficacy Between Some Formulations of Entomopathogenic Fungi with Botanical and Chemical Pesticides Against Onion Thrips, Thrips tabaci Lind)

Comparative Study of The Efficacy Between Some Formulations of Entomopathogenic Fungi with Botanical and Chemical Pesticides Against Onion Thrips, Thrips tabaci Lind)

Suitability of Formulated Entomopathogenic Fungi Against Hibiscus Mealybug, Nipaecoccus viridis (Hemiptera: Pseudococcidae), Deployed Within Mesh Covers Intended to Protect Citrus From Huanglongbing

Mesh exclusion bags are increasingly being adopted by Florida citrus growers to protect young citrus trees from Asian citrus psyllid, Diaphorina citri Kuwayama, and Huanglongbing disease. These mesh bags exclude larger insects such as D. citri but may allow entry of minute insects. Hibiscus mealybugs, Nipaecoccus viridis (Newstead), have been observed thriving in the micro-habitat created by these covers on trees. Entomopathogenic fungi (EPF) and insect growth regulators (IGRs) are effective against several mealybug species under various growing conditions, but their efficacy against N. viridis or within the microclimate within exclusion bags is unknown. Therefore, we evaluated various formulations of entomopathogenic fungi with and without IGR against N. viridis using laboratory bioassays. We then conducted semifield bioassays to determine effectiveness of EPF formulations alone and in combination with an IGR applied to citrus trees enveloped within mesh bags under field conditions. Survival probabilities of N. viridis nymphs exposed to all Beauveria bassiana-based products tested were comparable to malathion under laboratory conditions and reduced survival as compared to controls (water only). Under field conditions, mortality of N. viridis nymphs on leaves sprayed with each fungal formulation tested was significantly greater than on control treatments (Water, Suffoil X, 435 oil) up to four weeks post application. There were no differences in the colony forming units per leaf area amongst all fungal treatments. Formulated B. bassiana-based products applied alone or combined with an IGR should be effective tools for managing N. viridis populations on young citrus trees protected with mesh exclusion bags.

Management of the grape mealy bug, Maconellicoccus hirsutus (Green), using entomopathogenic fungi and botanical oils: a laboratory study

BackgroundLaboratory experiments were conducted to evaluate the bio-efficacy and cumulative effect of entomopathogenic fungi (EPF), viz., Lecanicillium lecanii (Zimmermann) Zare and Gams, and Beauveria bassiana (Balsamo) Vuillemin and different botanical oils against grape mealy bug, Maconellicoccus hirsutus (Green). M. hirsutus infestation during berry formation has left no option other than chemical management. However, the pesticide application during this stage leads to residues. Thus, safer and sustainable biological need was tested for their effectiveness against M. hirsutus.ResultsDipping bioassay technique was used to determine the cumulative mortality. When L. lecanii was used as sole (at 6 and 4 g/l), significant mortality was observed (51.63 and 50.18%). However, the maximum cumulative nymphal mortality was achieved when the combination of EPF formulations was used, i.e., 57.64% with B. bassiana + L. lecanii (6 g/l + 6 g/l). Their effectiveness was at par with the same combination but with minimal concentration, i.e., 4 g/l + 4 g/l (56.29%). Concerning the botanical oils evaluated, neem oil at 15 ml/l achieved a higher mortality of 81.36%. Consecutive effective treatment was a combination of neem oil and pongamia oil (at 10 + 10 ml/l) with 79.65% mortality. However, the standard dosage of neem oil (at 10 ml/l) and IIHR neem soap (at 10 g/l) also recorded the significant mortality of 78.09 and 77.67%, respectively. When compared, the neem oil was found significantly superior in sole and compatible combination than pongamia oil.ConclusionsLecanicillium lecanii and neem oil (sole and in combination with other compatible bioagents) proved significantly better for the management against M. hirsutus with an efficacy of 90.21 and 96.67 % mortality, respectively against the standard chemical control (more than 97%).

Endophytic colonization of tomato plants by the entomopathogenic fungus Beauveria bassiana for controlling the South American tomato pinworm, Tuta absoluta

BackgroundThe deployment of entomopathogenic fungi (EPF) for the control of crop pests is an important alternative to synthetic pesticides. Despite recent advances in EPF formulations and application techniques, their efficacy is still limited by abiotic and biotic factors. Entomopathogenic fungi naturally colonize plant tissues or they can be artificially inoculated, protecting the plants from insect attack. Beauveria bassiana is the most widely used fungal biological control agent and has potential as an endophyte to protect a range of crops. Although B. bassiana is known to be pathogenic to the South American tomato pinworm, Tuta absoluta (Meyrick), this fungus could be more efficient when deployed as an endophyte to protect tomato plants from attack.MethodsThree B. bassiana isolates were screened for virulence against T. absoluta larvae by application of conidia to leaf surfaces. Following confirmation of virulence, tomato plants were then exposed to conidial suspensions using a forced uptake technique. Only one isolate, LPP139, colonized the leaves. Seedlings were then inoculated with LPP139 and the presence of the fungus in different plant tissues was monitored over 30 days. Possible effects of B. bassiana endophytic colonization on plant development were also evaluated. Following confirmation of endophytic colonization of leaf tissues, T. absoluta 2nd or 3rd instar larvae were offered leaves and survival was monitored over a 7-day period.ResultsAll three B. bassiana isolates were virulent to T. absoluta, with approximately 90% mortality over 10 days when conidia had been applied to leaf surfaces. Various plant inoculation techniques were tested but only seedling inoculation was successful. LPP139 successfully colonized all of the plant tissues. High percentages of colonization were observed in roots, stems and leaves up to 30 days after inoculation, with no negative effects on plant growth. When T. absoluta larvae were exposed to B. bassiana colonized leaves, survival was reduced to zero over a 7-day period.ConclusionsThe endophytic colonization of tomato plants with EPF is a promising method of controlling the South American tomato pinworm. The fungus was detectable for up to 30 days, longer than has been previously observed for tomato plants. Seedling inoculation could be a viable commercial option for marketing pre-colonized tomato plants.

Management of the aphid, Myzus persicae (Sulzer) and the whitefly, Bemisia tabaci (Gennadius), using biorational on capsicum under protected cultivation in India

The peach aphid, Myzus persicae (Hemiptera: Aphididae) and silver leaf whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) are the major pests of capsicum under protected cultivation. The entomopathogenic fungi (EPF) are environmentally safe than the chemical pesticides. In the present study, different EPF formulations, Beauveria bassiana Balsamo (Vuillemin), Lecanicillium lecanii (Zimmerman) Viegas, Metarhizium anisopliae (Metschnikoff) Sorokin, were evaluated along with Azadirachtin 1% for the management of the aphid and the whitefly on capsicum under protected conditions. Result showed that talc formulation of L. lecanii MTCC 956 at 10 and 12 g/l caused 60.5 and 61.6% population reduction for aphid and 60.0 and 61.6% population reduction for whitefly, whereas Azadirachtin 1% at 4 and 5 ml/l caused 71.2 and 74.7% population reduction for aphid and 68.5 and 71.0% population reduction for whitefly after 3rd spray, respectively and were effective in reducing aphid and whitefly populations on capsicum recommending its organic production under protected cultivation and could be a part of integrated pest management program.

Pathogenicity of some commercial formulations of entomopathogenic fungi on the tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a major threat to tomato production in Rwanda. Laboratory bioassays were conducted to evaluate some commercial entomopathogenic fungi (EPF) formulations on T. absoluta larvae. The larvae, inside the leaf galleries, were obtained from the established tomato field. Commercial EPF: Metatech® WP [Metarhizium anisopliae (Metschn.) Sorok, Strain FCM Ar 23B3], Beauvitech® WP [Beauveria bassiana (Bals.) Vuill., Strain J25], and Botanigard ES [B. bassiana (Bals.), Strain GHA] were tested in Petri dishes against T. absoluta larvae at a concentration of 108 spores/ml. A synthetic insecticide, imidacloprid was included for comparison as a positive control, while water was used as a negative control. All the tested commercial EPF formulations were pathogenic to T. absoluta larvae in all conducted bioassays. Mortality rates increased with an increase in time (days). However, the insignificant difference was observed in the mortality of T. absoluta larvae treated with the commercial EPF during the first 3 days in all bioassays. Highly significant differences (p < 0.01) in pathogenicity among treatments were observed from the 4th to 6th days after inoculation. Metatech® WP and Beauvitech® WP recorded the highest mortality rates (82.8 and 60.8%) with the LT50 values of 3.9 and 5.2 days, respectively, while imidacloprid caused the least larval mortality. Since the EPF demonstrated high virulence level against the target pest, the efficacy of Metatech® WP and Beauvitech® WP should be advanced to field evaluation to determine their potential as alternatives to the synthetic insecticides.

Oviposition Deterrence and Immature Survival of Filth Flies (Diptera: Muscidae) When Exposed to Commercial Fungal Products

Filth flies are pests of livestock, and can transmit pathogens that cause disease to animals and their caretakers. Studies have shown successful infection of adult filth flies following exposure to different strains and formulations of entomopathogenic fungi. This study aimed to examine the effects of commercial formulations of Beauveria bassiana (Balsamo) (Moniliales: Moniliaceae) (i.e., BotaniGard ES, Mycotrol O, balEnce), and Metarhizium brunneum (Metsch.) (Ascomycota: Hypocreales) (i.e., Met52 EC), on filth fly oviposition and immature fly survival after exposure. House flies, Musca domestica L., laid significantly fewer eggs on Met52 EC-treated surfaces than on surfaces treated with all other products and the control. Similar numbers of eggs were laid on surfaces treated with all B. bassiana products, but egg production was half of the control. Stable flies, Stomoxys calcitrans (L.), laid the fewest eggs on Met52 EC- and Mycotrol O-treated surfaces. This species did not distinguish between the remaining products and the control. In a second experiment, house fly eggs were placed on treated cloths so that hatched larvae contacted the treatment prior to development. Met52 EC had the greatest effect on immature survival with a significant reduction in recovered pupae at the medium and high doses of fungi. Overall, Met52 EC, containing M. brunneum, had the greatest effect on house fly and stable fly oviposition deterrence and immature development of house flies. Management implications are discussed.

Biocontrol agents against the leafminer, Liriomyza trifolii in faba bean fields

Effect of entomopathogenic fungi formulations, Beauveria bassiana, Verticillium lecanii, Metarhizium anisopliae and Paecilomyces fumosoroseus, in controlling Liriomyza trifolii (Burg.) (Diptera: Agromyzidae), compared with botanical insecticide, Nimbecidine against L. trifolii was studied. Investigated compounds were applied twice at 15 days interval between sprays. The percentage reduction in larvae population and crop yield was estimated. Results showed that M. anisopliae was the most efficient compound among the other entomopathogenic fungi. Also, there were no significant differences between Nimbecidine and Bio-Magic (M. anisopliae). However, Nimbecidine and Bio-Magic caused 69.9 and 68.9% reduction in live larvae population after two applications. Also, Nimbecidine and Bio-Magic plots achieved 14.7 and 10.0 kg dry weight seeds/100 plants, respectively, compared to 5.7 kg dry weight seeds/100 plants in control plots. Nimbecidine and Bio-Magic were considered promising compounds in controlling L. trifolii and it could be exploitation in the integrated pest management programme of faba bean crop.

Efficiency of Nimbecidine and certain entomopathogenic fungi formulations against bean aphids, Aphis craccivora in broad bean field

This study investigates the effect of certain entomopathogenic fungi formulations (Beauveria bassiana, Verticillium lecanii, Metarhizium anisopliae and Paecilomyces fumosoroseus) compared with a botanical insecticide, Nimbecidine against Aphis craccivora in broad bean field. Bio-Catch (Verticillium lecanii) was the most effective insecticide to achieve 73.3% reduction followed by Nimbecidine (67.7%), Bio-Magic (61.6%), Priority (50.3%) and the least effective was Bio- Power (Beauveria bassiana) which caused 45.5% reduction in individual aphid populations after two sprayings at 15 days interval between the first and the second sprayings. Bio-Catch and Nimbecidine had promise compounds in controlling Aphis craccivora in faba bean fields.

Control of Main Stored-Grain Insects with New Formulations of Entomopathogenic Fungi in Diatomaceous Earth Dusts

The present research is aimed at a formulation of the entomopathogenic fungi, Beauveria bassiana (Bal.) Vuillemin and Metarhizium anisopliae (Metch.) Sorokin, in two types of diatomaceous earth dusts, fossil shield and Silico-Sec, are then applied against the adults of three species of stored-grain insects: Sitophilus oryzae L., Rhyzopertha dominica Fab. and Tribolium castaneum Herbs. Effect of the treatment was assessed by comparing the mortality percentage of the adults of the three insect species exposed to the formulated fungi with that of the adults exposed to the unformulated fungi or the diatomaceous earth dusts or the undisturbed control. Results obtained from these exposures have indicated that treatment of the adults with the formulated fungi resulted in a significantly higher mean mortality percentage compared to the treatment with the unformulated fungi or the diatomaceous earth dusts or the undisturbed control. A synergistic interaction between the effect of fungal species and the diatomaceous earth dusts was shown. Viability of conidia of both fungal species in diatomaceous earth dusts was assessed by calculating the germination percentage of the conidia over time. Results indicated a small loss of mean germination percentage for formulated conidia of both fungal species versus a high loss of mean germination percentage for the unformulated conidia, thus the diatomaceous earth dusts used in the formulation of both fungi demonstrated a negligible effect on the viability of formulated conidia compared to the unformulated.