Entomopathogenic Fungus Metarhizium Anisopliae Research Articles

An antifungal compound secreted by termite workers, phenylacetic acid, inhibits the growth of both termite egg-mimicking fungus and entomopathogenic fungi

AbstractSocial insects live in closely related family groups but face risks of intrusion and infection by pathogenic and parasitic microbes. To cope with the microbes invading their nests and feeding sites, social insects produce various types of antimicrobial substances. Subterranean termites occupy microbe-rich decaying wood and soil at high density, expanding their nest area by exploring and feeding on wood outward from the royal chamber (room for kings and queens). Although antimicrobial agents have been identified in many termite species, few studies have investigated those used by foraging workers in decaying wood under development, which is richer in microbes than the well-sterilized royal chamber and its surroundings. Here, we report that phenylacetic acid, an antifungal aromatic compound, is secreted by foraging workers of the Japanese subterranean termite Reticulitermes speratus. The compound was detected by gas chromatography–mass spectrometry analysis of ethyl acetate extracts of shelter papers infested with the workers, and antimicrobial tests demonstrated that it inhibits the germination and/or mycelial growth of the entomopathogenic fungi (Metarhizium anisopliae and Beauveria bassiana) and the termite egg-mimicking fungus Athelia termitophila. Our study provides new insights into the antimicrobial defense mechanisms of termites, including by combining different types of antimicrobial substances secreted by different castes, and thus the survival strategy of entomopathogenic and parasitic fungi in termite nests.

Different strategies between queens and workers against fungal pathogens in the termite Reticulitermes chinensis

AbstractSocial insects are prone to pathogen infection because of high exposure rates from social interactions. However, it remains unclear whether queens have enhanced pathogen resistance, because reproduction is largely confined to queens. Here, we used a natural host–pathogen system, the subterranean termite Reticulitermes chinensis and the entomopathogenic fungus Metarhizium anisopliae, to investigate the differences in allogrooming, locomotion, and immune gene expression between queens and workers against pathogen infection. We found that fungal infection significantly reduced survival in both queens and workers. Infected queens received significantly more grooming time from sanitary nestmates than infected workers, but they returned much less grooming time to sanitary nestmates than infected workers. Infection resulted in a reduction in the average locomotion speed and distance of queens but had no effect on worker locomotion. Infection resulted in upregulated expression of two immune genes (termicin and transferrin), two antioxidant genes (CAT and SOD), and phosphate genes CYP450 in queens but not in workers. Our results indicated that eusocial termites evolved strategies that prioritize the reproductive castes' welfare in defending against the pathogen infection to ensure continued reproduction and colony persistence.

Managing Super Pests: Interplay between Pathogens and Symbionts Informs Biocontrol of Whiteflies.

Bemisia tabaci is distributed globally and incurs considerable economic and ecological costs as an agricultural pest and viral vector. The entomopathogenic fungus Metarhizium anisopliae has been known for its insecticidal activity, but its impacts on whiteflies are understudied. We investigated how infection with the semi-persistently transmitted Cucurbit chlorotic yellows virus (CCYV) affects whitefly susceptibility to M. anisopliae exposure. We discovered that viruliferous whiteflies exhibited increased mortality when fungus infection was present compared to non-viruliferous insects. High throughput 16S rRNA sequencing also revealed significant alterations of the whitefly bacterial microbiome diversity and structure due to both CCYV and fungal presence. Specifically, the obligate symbiont Portiera decreased in relative abundance in viruliferous whiteflies exposed to M. anisopliae. Facultative Hamiltonella and Rickettsia symbionts exhibited variability across groups but dominated in fungus-treated non-viruliferous whiteflies. Our results illuminate triangular interplay between pest insects, their pathogens, and symbionts-dynamics which can inform integrated management strategies leveraging biopesticides This work underscores the promise of M. anisopliae for sustainable whitefly control while laying the groundwork for elucidating mechanisms behind microbe-mediated shifts in vector competence.

Effect of entomopathogenic fungi on behavior and physiology of Solenopsis invicta(Hymenoptera,Formicidae).

In an ant colony, a large number of nestmates with a similar gene pool coexist, making them more vulnerable to pathogenic attacks. These pathogens influence the behavior and physiology of the fire ant Solenopsis invicta Buren. Here, we evaluated the impact of entomopathogenic fungi (EPF) Metarhizium anisopliae on the behavior (locomotion and foraging) and physiology (biological molecules, anti-fungal activity, and survival) of S. invicta. Distance traveled and velocity significantly decreased, while turn angle and angular velocity significantly increased in ants exposed to a higher concentration of M. anisopliae compared to ants exposed to control after 36h, which showed disturbed locomotion. Fungus infection significantly affected the foraging behavior of ants. Fungus-exposed ants spent significantly less time in the food zone (area with food) than in the inner zone (area without food). The activities of 4 enzymes, peroxidase, glutathione-S-transferase, hydrogen peroxide (H2O2), and carboxylesterase were significantly decreased. In contrast, catalase and anti-fungal activities were increased after fungal exposure compared to the control. The activity of acetylcholinesterase, which hydrolyses the important neurotransmitter acetylcholine, also decreased after fungal application compared to the control. Survival of ants was also significantly reduced after fungus infection compared to the control. Our findings help to understand the influence of M. anisopliae on the behavior and physiology of S. invicta, which will help in the management of S. invicta using the EPF M. anisopliae.

Pesticidal activity of extra cellular metabolites extracted from the green muscardian fungi Metarhizium anisopliae

AbstractThe present study was undertaken to screen the pesticidal activity of extra cellular metabolites derived from entomopathogenic fungus Metarhizium anisopliae against Spodoptera litura and Aphis crassivora an important aphid pest under laboratory and pot culture condition. Fungal strain used in the study was isolated from the soil by serial dilution technique. Isolated fungal strain was mass multiplied in a liquid medium sabouraud maltose yeast extract broth under optimum condition (28°C). Culture filtrate and the collected culture derived from the medium was used for the source of metabolites. The culture filtrate was extracted with ethyl acetate, acetone and the concentrated extract was screened for pesticidal activity against Spodoptera litura and Aphis crassivora adopting leaf disc and pot culture assay respectively. Extracted metabolites showed pesticidal activity against both insect pests. However, notable effect was recorded in ethyl acetate derived metabolites. The ethyl acetate extract treatment recorded 91.2% mortality at a concentration of 100 μg against Spodoptera litura and 100% mortality at a concentration of 100 μg against Aphis crassivora. Phytotoxicity was determined by measuring the germination index (GI) of groundnut seeds by exposing it to the crude metabolites extracted in ethyl acetate and acetone. The results showed that the germination index was high on ethyl acetate extract which was recorded to be 98.0% and germination index of acetone extract was found to be 90.0%. Production of insecticidal metabolites from M. anisopliae under laboratory condition proposed the possible utilization of metabolites as an effective, safe pesticidal agent against economic important insect pests. No impact on the seedling emergence revealed non phytotoxic effect of the metabolites.

Dos inseticidas ao controle biológico de pragas na cana-de-açúcar: uma experiência de meio século na Venezuela

Biological control has been established as a unique measure for managing borers of the genus Diatraea and the candelilla Aeneolamia spp., both of which are key pests of sugarcane in Venezuela. Optimal results have been achieved with the use of parasitoids and entomopathogens. Systematic releases of the Amazonian fly Lydella minense from the mid-20th century and the establishment of the braconid wasp Cotesia flavipes from 1987 led to effective control of borers. In the case of Aeneolamia varia, a pest formerly controlled with frequent insecticide applications, an efficient solution was the introduction of the entomopathogenic fungus Metarhizium anisopliae in 1977. This measure has been established as efficient in controlling adult Aeneolamia, though nymphs were less controlled. This issue was effectively addressed in 2004 with the introduction of the entomopathogenic nematode Heterorhabditis bacteriophora, which has been widely used as a biological measure to avoid the application of insecticides. To illustrate this, we can consider the case of Azucarera Río Turbio. Despite experiencing a reduction in cultivated areas in recent harvests due to various factors, this establishment has witnessed a significant decline in Diatraea infestations over the past 58 years. Infestation rates have decreased from 15% to 3.18%, resulting in a saving of 170,552.62 metric tons valued at USD 49,196,045. The cost of implementing biological control measures amounts to USD 1,187,189, translating into a favorable benefit-cost ratio of USD 41.44. Before the adoption of biological control methods, Aeneolamia infestations were exclusively controlled using chemical insecticides applied to both the foliage for adults and the soil for nymphs. Concurrently, since then, entomopathogenic fungus M. anisopliae, produced by national companies, has been deployed across 87,000 hectares between 1986 and 1990. Moreover, since 2004, the use of entomopathogenic nematodes to control Aeneolamia nymphs has been integrated into pest management practices.

Entomopathogenic fungi based microbial insecticides and their physiological and biochemical effects on Spodoptera frugiperda (J.E. Smith).

'The fall armyworm, Spodoptera frugiperda', represents a significant threat to maize production, a major staple crop in Asian countries. In pursuit of more effective control of this insect pest, our study assessed the physiological and biochemical effects of the entomopathogenic fungus Metarhizium anisopliae against the larvae of S. frugiperda. Results revealed that, following nine days of treatment, a high concentration of conidia (1.5x107 conidia/mL-1) was toxic to all stages of larvae (second to fifth instar), resulting in 97% mortality of the second instar, 89% mortality of the third instar, 77% mortality of the fourth instar, and 72% mortality of fifth instar. All larval instars were found to have dose-dependent mortality effects. Treated S. frugiperda larvae further displayed significant physiological, morphological, and behavioral changes. Here, treated larvae displayed significantly lower levels of acetylcholinesterase, α-carboxylesterase, and β-carboxylesterase enzyme activity when compared to control groups. Treated larvae underwent an outward morphological change as the result of a decrease in the exterior cuticle of the anal papillae and a demelanization of the interior cuticle. Treated larvae also exhibited abnormal feeding behaviors as a consequence of the negative impact of conidia treatment on the neuromuscular system. Investigation into the effect of M. anisopliae on the non-target organism, the earthworm Eudrilus eugeniae, revealed that M. anisopliae conidia did not produce significant pathogenicity following three days of treatment. Furthermore, histological analysis revealed no significant effect of the entomopathogenic fungi on the gut tissue of the non-target organism. This study highlights the potential of M. anisopliae in the control of S. frugiperda.

Перспективы применения энтомопатогенных грибов для борьбы с постельными клопами

A literature review on the effectiveness of the use of entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana for the destruction of bed bugs is given. Bed bug resistance to pyrethroids does not result in cross-resistance to infection with B. bassiana spores. Insect mortality is highly dependent on the concentration of fungal conidia, which is critical to induce horizontal transfer capable of increasing insect population mortality without the need for direct contact between bed bugs and the inoculated substrate. Pyrethroid residues on treated surfaces significantly reduce the germination of B. bassiana spores. At present, resistance of insects to mycoinsecticides in the field has not been revealed, however, it has been shown that in laboratory conditions its occurrence is possible. Keywords: entomopathogenic fungi, Metarhizium, Beauveria, biopesticides, bed bug, resistance.

Bacterial microbiota associated with the leaf‐cutting ant Atta cephalotes (Hymenoptera: Myrmicinae): Dynamics during development and potential role in defence

AbstractThe biological complexity of leaf‐cutting ants is determined in part by both positive and negative associations with microorganisms. These ants constantly face microorganisms that can compromise workers’ survival and the integrity of their symbiont fungus. The ability to produce antimicrobial compounds within the colony, both by the workers and by associated microorganisms, is an adaptive response that protects against these natural enemies. Atta cephalotes (Linnaeus, 1758) is an ecologically successful species with a great capacity to overcome pathogenic microorganisms. In contrast to the Acromyrmex genus, the evidence suggests that it does not maintain an association with antibiotic‐producing actinobacteria raising the question of whether this species maintains associations with bacterial communities that can potentially protect the colony against prejudicial microorganisms. In this direction, the diversity and composition of the culturable bacterial microbiota associated with A. cephalotes developmental stages were evaluated, as well as their potential to inhibit the growth of the entomopathogenic fungus Metarhizium anisopliae and the mycoparasite Trichoderma sp. Six nests were collected, of which a total of 900 larvae, 900 pupae and 900 adult workers were analysed. Culture‐dependent and molecular methods were used to identify the strains to genus level. To determine differences in bacterial composition in the development stages, analysis of the contribution to dissimilarity (SIMPER) were performed. Seventy‐seven strains corresponding to 18 genera were documented. Acinetobacter was the dominant one. On the other hand, Acinetobacter, Bacillus, Enterobacter, Serratia and Microbacterium were maintained from the larval to the adult stage. Furthermore, except for Acinetobacter, different strains of these bacterial groups significantly inhibited pathogenic fungi growth. The results suggest the existence of a persistent association of A. cephalotes with strains of these bacterial genera and a potential role in defence at the collective level.

Caste composition contributes to improve the social immunity in a nasute termite species exposed to entomopathogenic fungus

Abstract The evolution of a reproductively altruistic caste contributed to the success of eusociality through the division of labour. In termites, the proportion of soldiers in the colonies increased throughout the group's evolution. In Nasutitermitinae, soldiers have a crucial role in defence, resource selection and foraging. However, the role of soldiers and workers in colony immunity is still poorly understood. Here, we evaluated the role of mixed caste groups in the social immunity of Nasutitermes corniger (Termitidae: Nasutitermitinae) exposed to the entomopathogenic fungi Metarhizium anisopliae (Metsch.). We tested the hypothesis that the presence of workers and soldiers optimizes defence against pathogens, and this defence is increased when the soldier ratio is closer to what naturally occurs in colonies. Our results showed that mixed caste groups of N. corniger exposed to M. anisopliae survive longer compared to groups with only one caste. In addition, termite groups that died from fungi were less likely to show fungal infection in mixed caste groups. The behavioural observations suggest that in the natural proportion of soldiers, allogrooming and trophallaxis play a crucial role in the control of disease and its death hazard in termites. Soldiers may play an important role in colony immunity, being able to start the alarm signal indicating the threat of pathogens. Our results show that the presence of the two castes promotes possible mechanisms for socially mediated immunity. This study may help in the understanding of the function of the soldiers and workers and the significance of pathogens in termite eusocial evolution.

Effectiveness test the entomopathogenic fungus Metarhizium anisopliae (Metch) at various concentrations against Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae) larvae in the laboratory

Spodoptera frugiperda is one of the most important major pests of maize in the world. Armyworms are polyphagous, the main target is corn, pests can move to other hosts if there is no primary host so that these pests can survive and maintain their populations throughout the year. S.frugiperda is also considered a serious insect pest because it reproduces in several generations per year and adults can fly up to 100 km per night, giving it the potential to spread widely in a short time. This study aim to determine the effectiveness of the entomopathogenic fungus Metarhizium anisopliae (match) at various concentrations against S. Frugiperda. This study was conducted in laboratory conditions, using a completely randomized design using four treatments and five replications. Each replicates used 20 test larvae. the treatments were: control, concentration of M. anisopliae 107, M. anisopliae 108, and of M. anisopliae 109. The larvae used as test larvae were instar 2 larvae, and observations were made every day to see the mortality of the test insects and record the symptoms that appeared in larvae after the application of M. anisopliae. The results showed that there was an effect of mortality on the test insects seen in treatment 108 showing the highest treatment of 9.15 days after application compared to all treatments. at 14 days post-application. The results of this study indicate the need for proper development for the purpose of effective pest control in crop cultivat.

Enhancing Red Ginger Plant Growth through Eco-Friendly Pest Management: Synergistic Effects of Metarhizium anisopliae and Imidacloprid

This study explores the potential of a more environmentally friendly pest management approach for enhancing the vegetative growth of red ginger plants (Zingiber officinale Rosc.) by mitigating the damage caused by Lepidiota stigma (white grub) larvae. The study was conducted at the Experimental Garden of the Faculty of Agriculture, UPN “Veteran” Yogyakarta from April to August 2022, utilizing a factorial Completely Randomized Design. The application of the entomopathogenic fungus Metarhizium anisopliae at varying doses (0 g, 10 g, 20 g, and 30 g per 3 kg of planting media) and the systemic insecticide Imidacloprid (either absent or at a dose of 0.02 g per 3 kg of planting media) were the primary factors studied. Each treatment combination, executed on ten plants each infested with one larvae, was repeated thrice. The findings demonstrate that a combined application of M. anisopliae and Imidacloprid could significantly reduce the intensity of white grub damage to red ginger plants and improve their vegetative growth. Notably, a dose of M. anisopliae of 20 g per 3 kg of planting media maximized the plant height, leaf number, and tiller count. The findings highlight the potential of integrating biological and chemical controls for sustainable pest management and crop yield improvement, with broad implications for other similar agricultural contexts.

Efektivitas Beauvaria bassiana dan Metarhizium anisopliae terhadap Pengendalian Hama Thrips sp. (Thysanoptera: Tripidae) pada Tanaman Cabai Besar (Capsicum annuum L.)

The productivity of chili plants can be reduced due to the disturbance of various Plant Pest Organisms (OPT), one of which is insect pests from the Order Thysanoptera, family Thripidae or better known as Thrips sp. Thrips pests attack plants by sucking the liquid on the leaf surface, especially the young leaves. Symptoms that appear are silvery spots then change color to copper brown, the leaves curl or wrinkle and eventually the plant dies. Control measures that can be used to control or suppress Thrips sp. pest populations. other than using insecticides, namely by utilizing Biological Control Agents (APH) such as the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana. The fungus B. bassiana infects host insects through physical contact by attaching conidia to the integument. M. anisopliae infection begins with the attachment of M. anisopliae spores to the cuticle of the insect and then the spores of M. anisopliae germinate and penetrate into the insect's body. This study used a field experiment method arranged in a Factorial Completely Randomized Design (CRD) with 2 factors and 4 replications. The first factor was the type of entomopathogenic fungus which consisted of two levels, A1 = Beauveria bassiana, A2 = Metarhizium anisopliae. The second factor was the density of conidia which consisted of 4 types: K1 = 105/ml, K2 = 106/ml, K3 = 107/ml, K4 = 108/ml. The observed data is quantitative data, then it will be analyzed statistically using ANOVA analysis of variance, if there is a significant difference then a follow-up test will be carried out using the DMRT. The effect of factor A1 (B. bassiana) is better than the effect of factor A2 (M. anisopliae) on the mortality of Thrips sp. and the best effect of factor K is on K4 (spore density 108/ml). So it is recommended to use the A1K4 treatment because it is effective on the mortality of Thrips sp. and the effect of factor K4 (spore density of 108/ml) was better than the effect of factors K1 (spore density of 105/ml), K2 (spore density of 106/ml), and K3 (spore density of 107/ml) on the intensity of attack of Thrips sp. So it is recommended to use the K4 treatment because it is effective against the intensity of attacks of Thrips sp.

Infection with a novel polymycovirus enhances growth, conidiation and sensitivity to UV-B irradiation of the entomopathogenic fungus Metarhizium anisopliae.

Metarhizium anisopliae is a well-studied entomopathogenic fungus that is widely used in biological control programs. The presence of polymycoviruses in this fungus is common, but their effects on fungal development and stress tolerance are not well understood. In this study, we report the discovery of a novel double-stranded RNA virus, named Metarhizium anisopliae polymycovirus 1 (MaPmV1), which comprises four dsRNAs ranging from 2.4 to 1.4 kbp in length. Phylogenetic analysis revealed that MaPmV1 belongs to the Polymycoviridae family. Biological comparison between MaPmV1-infected (Vi) and -free (Vf) isogenic lines showed that MaPmV1 remarkably enhances the growth rate and conidiation of the host fungus. The upregulation of growth- and conidiation-related genes in Vi strains supports this finding. In addition, MaPmV1 increases the sensitivity of the host to UV-B irradiation, which is evidenced by the downregulation of DNA damage repair genes in Vi strains. However, MaPmV1 does not appear to have any significant impact on the virulence of M. anisopliae. Furthermore, overexpression of individual viral proteins in M. anisopliae did not result in any significant phenotypic alterations, indicating that MaPmV1-mediated changes are not related to a single viral protein. Overall, our findings suggest that mycoviruses can be exploited to enhance fungal development in entomopathogenic fungi, which may lead to improved conidium production on a large scale.

Storability of the Entomopathogenic Fungus Metarhizium anisopliae

The present investigation on storability of the entomopathogenic fungus Metarhizium anisopliae was carried out at Biocontrol Laboratory, Agricultural Entomology Section, College of Agriculture, Dhule during Jan 2018 to Dec 2018. The pure culture of the entomopathogenic fungus M. anisopliae was maintained at Agricultural Entomology Section, College of Agriculture, Dhule on PDA slants. The storability of the fungus M. anisopliae was studied at 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 and 180 days after storage kept at ambient and freeze temperature. The CFU count was taken by serial dilution technique at 104, 105, 106, 107, 108 and 109 dilution 3 days after inoculation. At 15 day’s interval 1 gm sample was taken from both room and freeze temperature prepared samples of the fungus and the viability of the product was studied by serial dilution technique. The results clearly indicated that the viability of the product kept in ambient temperature was 120 days, while the viability of the product kept in freeze temperature was 165 days. Initial one month, the difference in CFU count among the samples kept at room and freeze temperature was less as compared to later stage of storage. The entomopathogenic fungus M. anisopliae can be stored safely up to 4 months at ambient temperature and maximum up to 5.5 months at freeze temperature.

Effects of destruxin A on hemocytes of the domestic silkworm, Bombyx mori.

Destruxin A (DA) is a mycotoxin isolated from the entomopathogenic fungus Metarhizium anisopliae which has demonstrated inhibitory activity against various insect species. However, the mechanism of inhibition on target sites in insects remains unknown. In this research, the dose-response relationship between DA and morphological changes in body tissues and organs of domestic silkworm, Bombyx mori, were investigated by histopathological methods to identify the target sites that responded to DA. The results showed that responses of individual tissues and organs varied with DA dosage and treatment time. At low doses (i.e., 0.01μg/g), the hemocytes were the most sensitive to DA with morphological changes apparent at 6 h after treatment. However, the muscle cells, fat body, and Malpighian tubules were unaltered. At higher doses (i.e., > 0.1μg/g), morphological changes were observed in muscle cells, fat body, and Malpighian tubules at 24 h after treatment. The results indicated that DA can be an immunosuppressant by damaging host cells like hemocytes, and at higher doses may potentially impact other physiological processes, including muscle function, metabolism, and excretion. The information presented in the current study will facilitate development of mycopesticides and novel immunosuppressants.

Viability of Entomopathogenic Fungi in Oil Suspensions and Their Effectiveness against the Agave Pest Scyphophorus acupunctatus under Laboratory Conditions

Oaxaca, Mexico, is home to over 30 species of the genus Agave, and its cultivation is of great economic and social importance for the mezcal industry, which depends on its production. The incidence of the pest Scyphophorus acupunctatus causes severe losses and damage. Agrochemicals are used for its control, but a viable alternative is microbial control. The objectives of this study were to determine the natural occurrence of the entomopathogenic fungi (EPF) Beauveria bassiana and Metarhizium anisopliae, isolated from S. acupunctatus in agave crops, and to evaluate the effect of vegetable oil in water emulsions containing conidia from the native fungi against adults of S. acupunctatus under laboratory conditions. Viability of the fungal isolates was determined at a concentration of ×108 conidia/mL in avocado (Persea americana), mamey (Mammea americana), chia (Salvia hispanica), or olive (Olea europaea) oil in water emulsions at two concentrations, 20% and 40%. The most effective oil emulsion on S. acupunctatus adults was determined under laboratory conditions. Naturally occurring fungi in 900 field collected insects was 2.21%. Ninety-six hours after preparing a 20% emulsion in P. americana oil, B. bassiana and M. anisopliae had a viability of 75% and 66.5%, respectively, while the control conidia suspended in distilled water remained viable for only 48 h. Twenty-four hours after applying M. anisopliae conidia in a 40% P. americana oil emulsion, effectiveness was 100% on S. acupunctatus, followed by M. anisopliae in 20% P. americana oil emulsion with 75% effectiveness. At 72 h post-application, all fungus in oil emulsions achieved an accumulated insect mortality of 100%, while the control showed no effect on adult S. acupunctatus. The most promising combination was 40% P. americana oil emulsion, which achieved 50% viable B. bassiana or M. anisopliae conidia up to 96 h after preparation, and its accumulated effectiveness on S. acupunctatus adults was 87.5% after 24 h.

Agroecological Management of Sphenarium Purpurascens with Vegetable Extracts and Entomopathogenic Fungi in Amaranth, Puebla-Mexico

Among the most important pests of amaranth (Amaranthus hypochondriacus L.) is Sphenarium purpurascens Charpentier, 1845 (Orthoptera: Pyrgomorphidae) which causes damage to the plant, decreased performance and economic losses, with chemical products being the main control method. The objective of this work was to evaluate the effect of aqueous extracts of Ricinus communis and Capsicum frutensis combined with two entomopathogenic fungi; one commercial and one native to Puebla-Mexico, alternated with the application of soap, in laboratory and field conditions. Bioassays were carried out to evaluate the compatibility of aqueous extracts with the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana at concentrations of 25, 50 and 75 % in conidia, in addition, six treatments with five repetitions were tested in a randomized block experimental design in the field. Los bioensayos de laboratorio presentaron diferencias significativas en el desarrollo micelial y tasa de crecimiento, donde se observó un estímulo positivo en el crecimiento de M. anisopliae por parte de los extractos vegetales. In the field, the H+Ch+M treatment registered the least damage (12.9%), least infestation (1.1%) and best seed production (1,353.7 kg/Ha). The effect of aqueous extracts combined with M. anisopliae, alternated with soap applications, proved to be an effective strategy in the integrated management of Sphenarium purpurascens, in amaranth cultivation in Puebla, Mexico.

Virulence of entomopathogenic fungi isolated from wild mosquitoes against Aedes aegypti

AbstractThe entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana are highly virulent control tools for insect pests and have been under evaluation for the control of globally important mosquito vectors such as Aedes aegypti. Here, we identified and isolated other virulent entomopathogenic fungi against Ae. aegypti. We collected 7 species of mosquitoes by human landing catch in 5 municipalities in Central and Northern Mexico and isolated 28 species of fungi. We harvested fungal conidia from six and assessed virulence against Ae. aegypti females. We observed variation in virulence of fungi in Ae. aegypti with the most virulent being Aspergillus tamarii, with a LT50 of 6.4 (±0.65) days and the least virulent was Trichoderma euskadiense with a LT50 of 16.3 (±1.5) days. Additional assays evaluated the impact of the fungi on Ae. aegypti fecundity and fertility and A. tamarii had the highest for both, resulting in 60% and 37% decrease, respectively. These results provide support for the potential utility of A. tamarii as an entomopathogenic control tool for the dengue vector, Ae. aegypti, pending further evaluations of environmental and nontarget safety.

Acoustic Comparisons of Red Palm Weevil (Rhynchophorus ferrugineus) Mortality in Naturally Infested Date Palms after Injection with Entomopathogenic Fungi or Nematodes, Aluminum Phosphide Fumigation, or Insecticidal Spray Treatments.

Red palm weevil (RPW) management is important to the economic success of date palm agriculture. Monitoring with acoustic sensors was conducted in naturally infested trees in date palm orchards for six months after treatments with entomopathogenic fungi (Beauveria bassiana and Metarhizium anisopliae), entomopathogenic nematodes (Steinernema carpocapsae), aluminum phosphide, emamectin benzoate, or fipronil to evaluate their efficacy in an integrated pest management treatment vs. a distilled water injection. Reductions in the mean rates of RPW sound impulse bursts over time after treatment were used as indicators of RPW mortality. Entomopathogenic fungi and nematodes, aluminum phosphide, and emamectin benzoate were the most effective treatments, reducing RPW impulse burst rates within 2-3-months to levels indicating absence of infestation. However, when applied as a spray, fipronil had only a minor effect. The results indicate that treatments utilizing entomopathogenic fungi or nematodes can beneficially manage RPW in palm orchards and can help to limit treatments that may induce insecticide resistance or cause human and environmental harm. Furthermore, the use of an acoustic sensor can be beneficial in monitoring the activities of insect borers inside the tree trunk.