Fungus Beauveria Bassiana Research Articles

Microencapsulation of a Native Strain of the Entomopathogenic Fungus Beauveria bassiana and Bioinsecticide Activity against Pyrethroid-Resistant Triatoma infestans to Vector Control of Chagas Disease in the Argentine Gran Chaco Region.

The blood-sucking bug Triatoma infestans is the main Chagas disease vector in the Southern Cone of Latin America. Populations resistant to pyrethroid insecticides have been detected in the early 2000s and then expanded to the endemic area of northern Salta province, Argentina. In this context, the entomopathogenic fungus Beauveria bassiana has been shown to be pathogenic to pyrethroid-resistant T. infestans. In this study, both the bioinsecticidal activity and the residual effect of an alginate-based microencapsulation of a native strain of B. bassiana (Bb-C001) were tested under semi-field conditions against pyrethroid-resistant T. infestans nymphs. Fungal microencapsulated formulation caused higher nymph mortality than the unmicroencapsulated fungus and contributed to maintaining the conidial viability throughout the period evaluated under the tested conditions. These results suggest that alginate microencapsulation is an effective, simple, low-cost method that could be incorporated into the formulation of a bioinsecticide as a strategy to reduce the vector transmission of Chagas disease.

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.

Economic Benefits from Managing Coffee Berry Borer (Hypothenemus hampei) in Hawaii

Coffee berry borer (CBB) is considered the most damaging insect pest of coffee worldwide. CBB was first detected on Hawai'i Island in 2010, and quickly spread throughout the state's coffee-growing regions. With the introduction of this pest, Hawaii's small yet economically important coffee industry was changed forever with growers facing significantly higher production and labor costs, as well as decreased yield and coffee quality. We assessed the economic benefits of managing CBB based on three strategies that emerged in Hawaii over the last decade: (1) the use of the entomopathogenic fungus Beauveria bassiana alone, (2) early integrated pest management (IPM), which combined monitoring and sanitation with spraying B. bassiana, and (3) research-based IPM, which focused on CBB biology in Hawaii, optimization of monitoring, B. bassiana applications, and cultural controls. From 2011 to 2021, the economic benefits from managing CBB were USD 52 million using B. bassiana alone, USD 69 million from early IPM, and USD 130 million from research-based IPM, for a total of USD 251 million from all management. Our findings suggest that all types of management provide economic benefits to Hawaii growers, but management strategies based on Hawaii-specific research have provided the greatest gains in coffee yield, price, and revenue.

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.

Adaptive Reproductive Strategies of an Ectoparasitoid Sclerodermus guani under the Stress of Its Entomopathogenic Fungus Beauveria bassiana.

Complex interspecific relationships between parasites and their insect hosts involve multiple factors and are affected by their ecological and evolutionary context. A parasitoid Sclerodermus guani (Hymenoptera: Bethylidae) and an entomopathogenic fungus Beauveria bassiana (Hypocreales: Cordycipitaceae) shared the same host in nature, Monochamus alternatus (Coleoptera: Cerambycidae). They often encountered the semi-enclosed microhabitat of the host larvae or pupae. We tested the survival and reproduction of the parasitoid's parent and its offspring fitness under different concentrations of B. bassiana suspension. The results show that S. guani parent females carrying higher concentrations of the pathogen shorten the pre-reproductive time and regulate their own fertility and their offspring's survival and development. This minimal model of the interspecific interactions contains three dimensionless parameters, vulnerability (θ), dilution ratio (δ), and PR, which were used to evaluate the mortality effect of the parasitoid S. guani on its host M. alternatus under the stress of the entomopathogenic fungus B. bassiana. We compared the infection and lethal effect of the fungus B. bassiana with different concentrations to the parasitoid S. guani and the host larvae M. alternatus. At higher concentrations of the pathogen, the parasitoid parent females shorten the pre-reproductive time and regulate their own fertility and their offspring's survival and development. At moderate concentrations of the pathogen, however, the ability of the parasitoid to exploit the host is more flexible and efficient, possibly reflecting the potential interspecific interactions between the two parasites which were able to coexist and communicate with their hosts in ecological contexts (with a high overlap in time and space) and cause interspecific competition and intraguild predation.

The Entomopathogenic Fungus Beauveria bassiana Employs Autophagy as a Persistence and Recovery Mechanism during Conidial Dormancy.

Many filamentous fungi develop a conidiation process as an essential mechanism for their dispersal and survival in natural ecosystems. However, the mechanisms underlying conidial persistence in environments are still not fully understood. Here, we report that autophagy is crucial for conidial lifespans (i.e., viability) and vitality (e.g., stress responses and virulence) in the filamentous mycopathogen Beauveria bassiana. Specifically, Atg11-mediated selective autophagy played an important, but not dominant, role in the total autophagic flux. Furthermore, the aspartyl aminopeptidase Ape4 was found to be involved in conidial vitality during dormancy. Notably, the vacuolar translocation of Ape4 was dependent on its physical interaction with autophagy-related protein 8 (Atg8) and associated with the autophagic role of Atg8, as determined through a truncation assay of a critical carboxyl-tripeptide. These observations revealed that autophagy acted as a subcellular mechanism for conidial recovery during dormancy in environments. In addition, a novel Atg8-dependent targeting route for vacuolar hydrolase was identified, which is essential for conidial exit from a long-term dormancy. These new insights improved our understanding of the roles of autophagy in the physiological ecology of filamentous fungi as well as the molecular mechanisms involved in selective autophagy. IMPORTANCE Conidial environmental persistence is essential for fungal dispersal in ecosystems while also serving as a determinant for the biocontrol efficacy of entomopathogenic fungi during integrated pest management. This study identified autophagy as a mechanism to safeguard conidial lifespans and vitality postmaturation. In this mechanism, the aspartyl aminopeptidase Ape4 translocates into vacuoles via its physical interaction with autophagy-related protein 8 (Atg8) and is involved in conidial vitality during survival. The study revealed that autophagy acted as a subcellular mechanism for maintaining conidial persistence during dormancy, while also documenting an Atg8-dependent targeting route for vacuolar hydrolase during conidial recovery from dormancy. Thus, these observations provided new insight into the roles of autophagy in the physiological ecology of filamentous fungi and documented novel molecular mechanisms involved in selective autophagy.

Divergent Physiological Functions of Four Atg22-like Proteins in Conidial Germination, Development, and Virulence of the Entomopathogenic Fungus Beauveria bassiana

In yeast, Atg22 functions as a vacuolar efflux transporter to release the nutrients from the vacuole to the cytosol after the degradation of autophagic bodies. There are more than one Atg22 domain-containing proteins in filamentous fungi, but their physiological roles are largely unknown. In this study, four Atg22-like proteins (BbAtg22A through D) were functionally characterized in the filamentous entomopathogenic fungus Beauveria bassiana. These Atg22-like proteins exhibit different sub-cellular distributions. BbAtg22A localizes in lipid droplets. BbAtg22B and BbAtg22C are completely distributed in the vacuole, and BbAtg22D has an additional association with the cytomembrane. The ablation of Atg22-like proteins did not block autophagy. Four Atg22-like proteins systematically contribute to the fungal response to starvation and virulence in B. bassiana. With the exception of ∆Bbatg22C, the other three proteins contribute to dimorphic transmission. Additionally, BbAtg22A and BbAtg22D are required for cytomembrane integrity. Meanwhile, four Atg22-like proteins contribute to conidiation. Therefore, Atg22-like proteins link distinct sub-cellular structures for the development and virulence in B. bassiana. Our findings provide a novel insight into the non-autophagic roles of autophagy-related genes in filamentous fungi.

Overdispersion Models for Clustered Toxicological Data in a Bioassay of Entomopathogenic Fungus

We consider discrete mortality data for groups of individuals observed over time. The fitting of cumulative mortality curves as a function of time involves the longitudinal modelling of the multinomial response. Typically such data exhibit overdispersion, that is greater variation than predicted by the multinomial distribution. To model the extra-multinomial variation (overdispersion) we consider a Dirichlet-multinomial model, a random intercept model and a random intercept and slope model. We construct asymptotic and robust covariance matrix estimators for the regression parameter standard errors. Applying this model to a specific insect bioassay of the fungus Beauveria bassiana, we note some simple relationships in the results and explore why these are simply a consequence of the data structure. Fitted models are used to make inferences on the effectiveness and consistency of different isolates of the fungus to provide recommendations for its use as a biological control in the field.

Effects of endophytism by Beauveria bassiana (Cordycipitaceae) on plant growth, Fusarium (Nectriaceae) disease, and Sunn pest Eurygaster integriceps (Hemiptera: Scutelleridae) in wheat (Poaceae)

Abstract Fungi living within a plant (i.e., endophytic fungi) can directly affect the growth of the host plant or have indirect effects by affecting levels of damage to the plant caused by insect herbivory or plant pathogens. Greenhouse and field trials were conducted to investigate the endophytic effects of the fungus Beauveria bassiana on wheat, on the wheat-feeding Sunn pest, Eurygaster integriceps (Hemiptera: Scutelleridae), and on the wheat pathogen, Fusarium culmorum (Nectriaceae), which causes root and crown rot disease. Conidia of B. bassiana were applied to wheat either by foliar spray, soil drench, or seed treatment. Seed treatment with conidia provided the highest re-isolation percentages: 91.7% in leaves, 95.8% in stems, and 91.7% in roots. Inoculated plants were taller and had greater wet and dry weights compared to control plants. In both greenhouse and field studies, E. integriceps that were fed inoculated plants laid eggs that were less likely to hatch. Inoculations reduced the incidence of root and crown rot disease by 42% under greenhouse conditions. These results document the potential of using endophytic infections of B. bassiana in wheat as a control measure for Sunn pest and root and crown rot disease.

Evaluation of Beauveria bassiana and Beauveria pseudobassiana Against Tanymecus dilaticollis

The grey corn weevil, Tanymecus (Episomecus) dilaticollis Gyll., (Curculionidae: Entiminae) is the most destructive pest of maize and sun flower crops in Romania. In this article we report result of evaluation of native strains of entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. (Deuteromicotina: Hyphomycetes) and B. pseudobassiana Rehner et Humber against Tanymecus dilaticollis (Curculionidae: Entiminae) both in laboratory and field. In laboratory assay, two different strains of B. bassiana and one strain of B. pseudobassiana (BbLy) were applied on insects as 1×108 conidia/ml aqueous suspensions. The pure ATCC 74040 commercial strain of B. bassiana and the commercial mycoinsecticide based on this strain (Naturalis) were included in the laboratory assay for comparison. Adult mortalities were recorded daily, 14 days post-exposure. All the fungal strains have been shown to be pathogenic to T. dilaticollis. The B. bassiana strain (BbTd1) and the B. pseudobassiana strain (BbLy) were effective against adults of T. dilaticollis and comparable in percentage of mycosis and virulence to the B. bassiana strain ATCC 74040. The commercial product Naturalis was superior to the tested fungal strains killing the insects within a day. In the field, the strains BbTd1 and BbLy applied as conidia multiplied on barley grains (1×109 /g d.w) in the soil did not affect the T. dilaticollis density in maize crop.

Efficacy of Some Local Isolates of the Fungus Beauveria bassiana (Bals.-Criv.) Vuill Towards the Immature Stages of the Fall Armyworm, Spodoptera frugiperda (J. E. Smith)

Alshadidi, B., J. Faddoul and A. Basheer. 2023. Efficacy of Some Local Isolates of the Fungus Beauveria bassiana (Bals.-Criv.) Vuill Towards the Immature Stages of the Fall Armyworm, Spodoptera frugiperda (J. E. Smith). Arab Journal of Plant Protection, 41(4): 384-390. https://doi.org/10.22268/AJPP-41.4.384390 The fall armyworm, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is one of the major pests that attack the maize crop. The use of entomopathogenic fungi is considered one of the most important strategies in managing this invasive pest as opposed to synthetic pesticides that are hazardous to human, environment and biodiversity. The experiments were conducted at the Biological Control Studies and Research Center (BCSRC), Faculty of Agricultural Engineering, University of Damascus during the period 2020-2022. The efficiency of seven Beauveria bassiana isolates was evaluated on the immature stages of armyworm. Isolates KA.1 and BS.5 caused the highest eggs mortality rate, 88.17 and 83.40%, respectively, when applied at a concentration of 1 x 108 spores/ml7 days after treatment. Isolate BS.5 caused the highest mortality rate of 54.77% at the same spore concentration and there was no significant effect on second instar larvae and pupae. However, when the isolate KA.1 was used, the highest mortality rate was in the pupa and reached 21.27 % two weeks after treatment. Thus, B. bassiana fungus can be applied with high efficiency in controlling the armyworm community, especially in the early larval stages. Keywords: Entomopathogenic fungi, larval stages, Spodoptera frugiperda.

MANAGEMENT OF CORN CICADA WITH BIOINSUMOS A BASE OF FUNGUS (BEAUVERIA BASSIANA)

Bioinsumos are governed by Federal Decree no. 10. 375 of May 26, 2020, which uses in its attributions, bioinsumption is considered the product, process or technology of plant, animal or microbial origin, intended for use in the production, storage and processing of agricultural products, in aquatic production systems or planted forests, which positively interfere in the growth, development and response mechanism of animals, plants, microorganisms and derived substances and that interact with products and physicochemical and biological processes. The bioinputs compatibility test was performed using the fungus Beauveria bassiana (Bals.) Vuill., strain PL63 (minimum of 1 x 108 viable conidia/ge and Isaria fumosorosea CEPA ESALQ-1296 (min. of 2.5 x 109 viable conidia/mL) at a dose of (500 gr/ha) associated with the insecticide based on Bifenthrin + Carbosulfan (600 mL/ha). In the field, the experiment was conducted in Sitio Santa Maria in the Municipality of Bandeirantes-PR located between the coordinates 50º37'63" WO and 23º15'79" S. Data collection was performed over a period of 4 months, with 1 crop in the management of corn culture. Soil analysis was performed (0 to 20 cm depth). The work for the evaluation of the fungus and insecticide, being carried out in the field, when the plants presented in the phase V2, V4, V6. The evaluations took place at 3, 7, 10, 14 days, after each application, total area considered (m2). The experimental design used was randomized blocks with 4 repetitions, with 15.75 m² plots (2.25 x 7) and spacing of 45 centimeters between rows, constituting 6 treatments, totaling 24 plots.

Efficacy of the entomopathogenic fungi Beauveria bassiana and Lecanicillium muscarium in the control of the tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Abstract Background Among the phytosanitary problems, affecting tomato crops in greenhouses heated by geothermal water in southern Tunisia, the tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is gaining prominence from year to year. Results This study determined the susceptibility of eggs, second-instar larvae of T. absoluta to commercial formulations of the entomopathogenic fungi (EPF) Beauveria bassiana and Lecanicillium muscarium at different doses (1010, 109, 108, 107 and 106 spores/ml). Pathogenicity tests were carried out under controlled laboratory conditions at 27 ± 1 °C, and RH of 75 ± 5%, showed that the three commercial formulations of B. bassiana R444 (Bb-Protec®), B. bassiana ATCC 74,040 (Naturalis®) and L. muscarium Ve6 (Mycotal®) were effective against eggs and second instar larvae of T. absoluta. Mortality rates of eggs and larvae were high with increasing the concentrations of the fungi. B. bassiana ATCC 74,040 was the most effective one, with an egg mortality rate of (71.42%) and larval mortality was greater than (80%), at the highest concentration of 1010 spores/ml. The lethal concentration required to kill 50% of eggs was 1.56 × 108, 1.73 × 109 and 1.09 × 1010 conidia/ml for B. bassiana ATCC, B. bassiana R444, and L. muscarium, respectively. After 7 days, the median lethal concentration (LC50) values against larvae were the lowest for B. bassiana ATCC with 2.63 × 107 and 4.76 × 106 conidia/ml by way 1 and way 2 treatments, respectively. Thus, these three formulations affected the emergence of pest’s adults. The fungi significantly reduced pupation and adult emergence. Only 50.25, 60.15 and 69.16% of T. absoluta adults emerged in the treatments with B. bassiana ATCC, B. bassiana R444, and L. muscarium, respectively. Conclusions Biological performances of the EPF showed the role of a biological control agent that can be played against T. absoluta within the framework of an Integrated Pest Management program.

Pengaruh penambahan kitosan pada media tumbuh Beauveria bassiana (Bals.) Vuill terhadap pertumbuhan, perkembangan, dan virulensinya pada walang sangit (Leptocorisa acuta F.)

Perbanyakan cendawan Beauveria bassiana yang dilakukan beberapa kali pada media alami akan menyebabkan penurunan virulensi. Solusi untuk mengatasi penurunan pertumbuhan B. bassiana untuk mempertahankan virulensi cendawan B. bassiana, yaitu dengan penambahan kitosan pada media tumbuh dengan konsentrasi yang tepat. Penelitian ini bertujuan untuk menguji pengaruh penambahan kitosan pada beberapa konsentrasi terhadap pertumbuhan, perkembangan, dan virulensi B. bassiana. Penelitian ini disusun menggunakan rancangan acak lengkap dengan 6 perlakuan dan 4 ulangan. Adapun perlakuan yang digunakan, yaitu P0 (kontrol), P1 (kitosan 1 mg/ml), P2 (kitosan 2 mg/ml), P3 (kitosan 3 mg/ml), P4 (kitosan 4 mg/ml), dan P5 (kitosan 5 mg/ml). Hasil penelitian menunjukkan bahwa kitosan berpengaruh terhadap pertumbuhan dan perkembangan cendawan B. bassiana. Diameter koloni tertinggi terjadi pada perlakuan P1, yaitu 8,34 cm dan viabilitas konidia tertinggi juga terjadi pada perlakuan P1, yaitu 85,26%. Pengaruh penambahan kitosan pada perlakuan P1 menunjukkan virulensi tertinggi pada Leptocorisa acuta L. dengan mortalitas imago sebesar 90% selama 10 hari setelah inokulasi (HSI) dan mortalitas pada stadia nimfa sebesar 95% selama 7 HSI. Pengamatan mikosis tertinggi terjadi pada P1 dengan persentase mikosis imago 66,81% dengan lama waktu 2,37 hari dan persentase mikosis nimfa 73,61% dengan lama waktu 2,25 hari. Pengamatan mumifikasi tertinggi terjadi pada P1 dengan persentase mikosis imago 62,02% dengan lama waktu 4,05 hari dan persentase mikosis nimfa 67,56% dengan lama waktu 3,99 hari. Penambahan kitosan sebesar 1 mg/ml pada media pertumbuhan jamur berpengaruh baik terhadap pertumbuhan dan virulensi B. bassiana.

Efficacy of the entomopathogenic fungus, Beauveria bassiana and Lecanicillium muscarium against two main pests, Bemisia tabaci (Genn.) and Tetranychus urticae (Koch), under geothermal greenhouses of Southern Tunisia

BackgroundThe geothermal greenhouses in Southern Tunisia are an important axis of agricultural development. This sector faces many abiotic and biotic constraints that could threat its sustainability. Thus, the heated greenhouses encounter destructive pests such as the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and the two-spotted spider mite Tetranychus urticae (Koch) (Acari: Tetranychidae).ResultsThis study aimed to assess the effect of the entomopathogenic fungi (EPF) Beauveria bassiana (strain ATCC and strain R444) and Lecanicillium muscarium strain Ve6 on simultaneous existence of T. urticae and B. tabaci in the host plants. The EPF had a significant effect on eggs and larvae of B. tabaci and on eggs and mobile forms of T. urticae in particular. The use of B. bassiana ATCC, B. bassiana R444 and L. muscarium strains Ve6 showed significant efficacies against B. tabaci larvae and eggs compared to untreated control. Indeed, the reduction percent of B. tabaci eggs varied between 42.65 and 58.52%. Thus, the efficacy against the number of B. tabaci larvae was in order to 65.04, 60.26 and 55.52% of B. bassiana strain ATCC, B. bassiana strain R444 and L. muscarium strain Ve6, respectively. In addition, these EPF were very effective on T. urticae eggs with a percentage reduction greater than 92.86%, whereas the percentage reduction in the T. urticae mobile forms varied between 95.11 and 98.52%.ConclusionsUse of EPF will be an imperative to develop directed interventions at the integrated management of these two pests in protected and geothermal crops.

Lethal Concentration and Sporulation by Contact and Direct Spray of the Entomopathogenic Fungus Beauveria bassiana on Different Stages of Nezara viridula (Heteroptera: Pentatomidae).

The southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae) is the most significant pest of soybean worldwide. The present study was conducted to compare the effectiveness of a Delta native strain NI8 of Beauveria bassiana by contact and direct spray on nymphs (2nd to 5th instar) and adults of N. viridula. Water control and four concentrations of B. bassiana were used to evaluate the survival, mortality, and molting percentage and to estimate median lethal concentration (LC50), median lethal sporulation (LS50), and resistance ratio (RR50). Direct spray at all concentrations observed the greatest reduction in survival on all life stages. Mortality and sporulation were positively correlated by concentration, while molting was highly variable with a significantly lower negative correlation on insects that were directly sprayed. Pathogenicity exhibited reduction as young stages developed and emerged to adult. The LC50 (Contact: 612 spores/mm2; Direct spray: 179 spores/mm2) and LS50 (Contact: 1960 spores/mm2 Spray: 3.3 × 106) values showed that adults of N. viridula were highly resistant than any other life stage when exposed to either contact or direct spray. Fourth instar was the most susceptible (LC50: Contact: 18 spores/mm2; Direct spray: 23 spores/mm2) (LS50: Contact: 53 spores/mm2; Direct spray: 26 spores/mm2) followed by second, third, and fifth instars.

The effect of the fungus Beauveria bassiana on different stages of cowpea weevil Callosobrushes Maculantus (fab.) (Coleoptera: Bruchidae).

A study in year 2006 show the effect of the fungus Beauveria bassiana in percentages of killing different stages of the insect cowpen weevil callosobrunchus maculates in three different dilutions 3.4 × 10-6 , 3.4 × 10-5 × 3.4 × 10-6 spore/ML in constant temp. 28 ± 2 C and R.H.75 ± 5%. The best dilution was 3.4×10-6 the percentage of egg hatching 30 % and percentage killing for the four larval in star was 43.3 # and also percentage killing at the pupae 70% and percentage killing of adult 100% male and female.

Application of the local entomopathogenic fungus Beauveria Bassiana Vuill against larvae Oryctes rhinoceros L. in immature oil palm plants in Sei Siasam, Rokan Hulu Regency, Riau Province, Indonesia

The decline in oil palm production can be caused by pest attacks. The main pest that attacks oil palm is the horn beetle. Control is usually done by using chemical pesticides. The use of chemical pesticides can cause resistance, resurgence, destruction of natural enemies, and environmental pollution. The use of chemical insecticides can be minimized by using environmentally friendly and sustainable control alternatives, namely by using the local entomopathogenic fungus B. bassiana. This study aimed to obtain the best dose of local B. bassiana Vuill in controlling O. rhinoceros larvae in immature oil palm plantations in Sei Siasam, Rokan Hulu Regency, Riau Province. The study was carried out in Sei Siasam, Rokan Hulu Regency and the Plant Pest Laboratory, Faculty of Agriculture, University of Riau. Completely Randomized Design with five treatments doses of local entomopathogenic fungus B. bassiana 30 g/hole, 35 g/hole, 40 g/hole, 45 g/hole, 50 g/hole and four replications, in order to get 20 experimental units. The results showed that the application of local Riau B. bassiana at a dose of 40 g/hole was the best dose capable of causing death of 72.5%. Early death 77 hours after application and Lethal time 50 180.75 hours after application.

Antimicrobial peptides expressed in the fat body of Spodoptera frugiperda (Lepidoptera: Noctuidae) in response to the microbial challenge

Spodoptera frugiperda (Lepidoptera: Noctuidae) is the key pest in maize crops and has a major impact on world agriculture. Several studies on the biological control of this species have been carried out, and these demonstrate resistance to biological control and pesticides. However, the humoral immune system of S. frugiperda is not yet completely known in relation to the innate immune response to biological control agents. The aim of this study was to evaluate the expression of Gloverin, Sf-gallerimycin, and Attacin genes in the fat body of larvae at the 6th instar of development. Our work confirmed the expression of Sf-gallerimycin in response to the bacterial challenge, 24 h post-inoculation, and revealed the expression of Gloverin and Attacin for the first time for both bacterial challenge and entomopathogenic fungus Beauveria bassiana challenge. Gloverin and Attacin genes were upregulated under the conditions analyzed. In addition, we revealed the presence of two probable antimicrobial peptides in the hemolymph, induced 24 h post challenge with the microorganisms. The 4.7 kDa band b is probably a defensin-like peptide, and the 6.1 kDa band a is a peptide not yet reported in S. frugiperda.

Effect of Bed Bug (Hemiptera: Cimicidae) Aldehydes on Efficacy of Fungal Biopesticides.

The use of the entomopathogenic fungus Beauveria bassiana (Bals. - Criv.) Vuill. (Hypocreales: Cordycipitaceae) has been recently incorporated in the management of bed bugs, Cimex lectularius L. (Hemiptera: Cimicidae). Bed bugs produce a set of aldehydes that are known to affect the growth of some fungi. Considering that bed bugs or their exuviae release these aldehydes, it was suspected that the bed bugs' aggregation sites would contain an increased level of the bed bug aldehydes. The current study examined if elevated levels of the bed bug aldehydes in the microhabitats would impact the efficacy of B. bassiana. Following a brief exposure to the residues of commercial products containing B. bassiana, the treated bed bugs were kept in a vial with or without a natural or artificial blend of bed bug aldehydes (i.e., exuviae or synthetic compounds). For a B. bassiana product that is not currently registered for bed bugs control, the presence of aldehydes significantly reduced 15-d mortality (61-62%) compared to the no aldehydes control (97.7%). However, when tested with a B. bassiana formulation designed for bed bug control, the aldehydes only caused delayed mortality for the treated bed bugs. When tested in culture, the growth rate of B. bassiana on a medium was significantly reduced when the bed bug aldehydes were provided in the headspace. Implications on practical bed bug management using fungal biopesticides are discussed.