Soil properties affect the availability, movement, and virulence of entomopathogenic fungi conidia against puparia of Ceratitis capitata (Diptera: Tephritidae)

The Mediterranean fruit fly, Ceratitis capitata Wiedemann (Diptera: Tephritidae), is the major tephritid pest in the Mediterranean region. This insect may overwinter as pupae inside fruits or in soil. Therefore, infection with entomopathogenic fungi is a potentially useful control technique during the insect’s soil-dwelling stage. Entomopathogenic fungi have an important role in Integrated Pest Management programs as an alternative to conventional chemical control, but they have been usually selected on the basis of laboratory results with little regard to fungal ecology. In this work, we designed several experiments to study the availability and movement of the EF Beauveria bassiana (Balsamo) Vuill. and Metarhizium anisopliae (Metsch.) conidia in 16 soils differing widely in pH, texture, organic matter, and carbonate contents. Experiments of adsorption and drag of conidia by soil particles suspended in CaCl₂ solutions of different ionic strength showed B. bassiana conidia to be retained by clay particles, and this effect disappeared with increasing ionic strength. The availability of M. anisopliae conidia in the suspension tended to be lower for sandy than for clayey soils and was not influenced by ionic strength. Regardless of soil properties, over 90% of the added fungal propagules were recovered from the surface layer of columns of packed soils representing model combinations of texture (sandy or clayey) and pH values (acid or alkaline). However, retention of B. bassiana conidia in the surface layer was higher in clayey than in sandy soils, and the retention of M. anisopliae conidia in the surface layer was higher in sandy than in clayey soils. Finally, neither soil texture nor ionic strength affected the infectivity of conidia of both fungal strains to C. capitata puparia.     

Soil management effects on entomopathogenic fungi during the transition to organic agriculture in a feed grain rotation

The growing demand for organic products creates opportunities for farmers. Information on the consequences of management practices can help farmers transition to organic and take advantage of these prospects. We examined the interaction between soil disturbance and initial cover crop on naturally occurring entomopathogenic fungi (EPF) during the 3-year transition to organic production in a feed grain rotation in central Pennsylvania. Our experiment included four systems comprised of a factorial combination of two levels of primary tillage (full vs. reduced) and two types of initial cover crop (timothy/clover vs. rye/vetch). The cropping sequence consisted of an initial cover crop, followed by soybean, and finally, maize. The entire experiment was replicated in time, with the initiation lagged by 1 year. We detected four species of EPF (Metarhizium anisopliae, Beauveria bassiana, Isaria fumosorosea, and Isaria farinosa) by bioassay of soil samples collected four times during each field season. The latter three species were detected infrequently; therefore, we focused statistical analysis on M. anisopliae. Detection of M. anisopliae varied across sampling date, year in crop sequence, and experimental start, with no consistent trend across the 3-year transition period. M. anisopliae was isolated more frequently in the systems initiated with timothy/clover cover crops and utilizing full tillage; however, we only observed a tillage effect in one temporal replicate. M. anisopliae detection was negatively associated with soil moisture, organic matter, and zinc, sulfur, and copper concentrations in the soil. This study helps to inform farmers about management effects on soil function, specifically conservation biological control.     

Entomogenous Fungi as Promising Biopesticides for Tick Control

When ticks were sealed in nylon tetrapacks and infected with the entomogenous fungi, Beauveria bassiana and Metarizium anisopliae and maintained in potted grass in the field, the fungal oil formulations (10⁹ conidia per ml) induced 100% mortality in larvae of Rhipicephalus appendiculatus and Amblyomma variegatum, whereas mortalities in nymphs varied between 80–100% and in adults 80–90%. The aqueous formulations (10⁹ conidia per ml) induced mortalities of 40–50% and reductions in egg hatchability of 68% (B. bassiana) and 48% (M. anisopliae) when sprayed on Boophilus decoloratus engorging on cattle. The strains of B. bassiana and M. anisopliae isolated from naturally infected ticks were also found to induce high mortalities in both R. appendiculatus and A.variegatum in tetrapacks placed in potted grass. Both aqueous and oil-based formulations were found to be effective, although the latter induced higher mortalities. These fungal strains in aqueous formulation (10⁸ conidia per ml) suppressed on-host populations of adult R. appendiculatus by 80% (B. bassiana) and 92% (M. anisopliae) when sprayed on tick-infested grass once per month for a period of 6 months. The feasibility of using entomogenous fungi for tick control in the field is discussed.     

The development and multiple uses of a standardised bioassay method to select hypocrealean fungi for biological control of aphids

A technically standardised bioassay method was designed, evaluated and used to assess virulence and host range of hypocrealean fungi against aphids. A track mounted sprayer was used to apply conidia because hand held versions of the same sprayer can be used for field applications, thereby allowing the outcome from laboratory experiments to predict activity in the field accurately. Eighteen fungal isolates were assessed in single concentration bioassays against the black bean aphid Aphis fabae Scopoli. Isolates comprised commercially available mycoinsecticides (based on Beauveria bassiana and Lecanicillium longisporum) and isolates of B. bassiana, Lecanicillium spp., Paecilomyces fumosoroseus and Metarhizium anisopliae. Aphid mortality was in excess of 80% for 15 isolates, and HRI 1.72 (L. longipsorum), Z11 (P. fumosoroseus), Mycotech strain GHA (B. bassiana) and ARSEF 2879 (B. bassiana) were studied further. Multiple concentration bioassays identified HRI 1.72 as the most virulent isolate against A. fabae with significantly smaller LC₅₀ and LT₅₀ values compared to other isolates. A precise LC₅₀ value (2.95 × 10² conidia ml⁻¹) was calculated for HRI 1.72 using a second multiple concentration assay with smaller concentrations of conidia. The four isolates were applied at a single concentration (1 × 10⁸ conidia ml⁻¹) against Myzus persicae, A. fabae, Acyrthosiphon pisum, Metopolophium dirhodum, Sitobion avenae and Rhopalosiphum padi. A ranking of aphid susceptibility was obtained, such that S. avenae > M. persicae, A. pisum, A. fabae > R. padi. Results indicate the importance of standardising bioassay methods to reduce bioassay variability without compromising the ability to use the bioassay to investigate fungus–host interactions under varying abiotic and biotic conditions.     

Horizontal transmission of mycotic infection in adult tsetse,Glossina morsitans morsitans

AdultGlossina morsitans morsitans exposed to wet conidia ofBeauveria bassiana andMetarhizium anisopliae suffered high mortalities ranging from 90 to 100% by 2 weeks post-exposure. Infected ♂ ♂ maintained in the same cages with non-infected ♀♀ throughout the experimental period transmitted the fungal infection to the ♀♀ resulting in mortalities of 65% withB. bassiana and 55% withM. anisopliae. Likewise, infected ♀♀ maintained together with non-infected ♂♂ transmitted the infection to the ♂♂ resulting in mortalities of 75% withB. bassiana and 45% withM. anisopliae. Female tsetse flies infected withB. bassiana andM. anisopliae and maintained in the same cages with non-infected ♀♀ also transmitted infection to the non-infected tsetse resulting in mortalities of 62% and 48% withB. bassiana andM. anisopliae respectively. Infected tsetse exposed to non-infected tsetse of the opposite sex for only 30 min were also able to transmit the fungal infection. Pupae produced by female tsetse infected withB. bassiana andM. anisopliae exhibited higher pupal mortality than those produced by non-infected ♀♀. However, pupae exposed directly to dry spores ofB. bassiana andM. anisopliae had no increase in pupal mortality but adults emerging from theB. bassiana-exposed pupae had markedly reduced longevity.      

Isolation of Beauveria bassiana and Metarhizium anisopliae var. anisopliae from Boophilus microplus tick (Canestrini, 1887), in Rio de Janeiro State,Brazil

The objective of this work were to isolate and identify strains of entomopathogenic fungi from ingurgitated female Boophilus microplus ticks, collected from the soil in the municipality of Paracambi, Rio de Janeiro State, Brazil. The ingurgitated females were inoculated in the selective medium oat dodine agar (oda), where 49 colonies of Beauveria bassiana (71%) and 20 of Metarhizium anisopliae var. anisopliae (29%) were isolated. These isolated strains characterize for the first time in Brazil the natural occurrence of these species of fungi in this tick, and will be used to conduct bioassays to evaluate the pathogenicity and virulence of these strains for ticks of the genus Boophilus microplus. This revised version was published online in June 2006 with corrections to the Cover Date.     

Natural occurrence of soil-borne entomopathogenic fungi in the Moroccan Endemic forest of <Emphasis Type="Italic">Argania spinosa</Emphasis> and their pathogenicity to <Emphasis Type="Italic">Ceratitis capitata</Emphasis>

The occurrence and abundance of entomopathogenic fungi were analysed in 203 soil samples of the Moroccan endemic forests of Argania spinosa, the world main refuge of the Mediterranean fruit fly, Ceratitis capitata. Using the Galleria baiting method and selective media, entomopathogenic fungi were isolated from 186 of the 203 (91.62%) soil samples, with only three species found: Beauveria bassiana (Balsamo) Vuillemin, Metarhizium anisopliae (Metschnikoff) Sorokin and Paecilomyces lilacinus (Thom.) Samson. B. bassiana was the most widespread entomopathogenic fungi (90.64%) in the Argan forest whereas M. anisopliae was less common (15.27%) and P. lilacinus was very rare (1.48%). This is the first report of natural occurrence of M. anisopliae and P. lilacinus in Morocco. Furthermore, 118 Moroccan B. bassiana isolates were studied for their pathogenicity to C. capitata and thermotolerance. Most of these autochtonous B. bassiana isolates were virulent (86.44%) to Medfly pupae and tolerant (55.08%) to temperature stress at 45°C for 2 h. Only 60.17% of Moroccan B. bassiana isolates might be considered as highly entomopathogenic and will serve as a source of potential biological control agents to C. capitata. The percentage of thermotolerant and pathogenic B. bassiana to C. capitata were shown to decrease significantly at winter time characterized by low temperatures and absence of any noticeable medfly in the Argan forest. The occurrence, thermotolerance and virulence of B. bassiana isolates to C. capitata seemed to be related to the sampling periods and location. Our data are discussed with respect to fungal ecology and biocontrol potential of B. bassiana isolates in relation to their habitat.     

西花蓟马高毒力虫生真菌筛选及其生防应用潜力的研究进展

西花蓟马是一种外来入侵的世界性害虫,对农林业危害巨大。查阅国内外相关文献,综述了当前防治西花蓟马的虫生真菌的种类、高毒力菌株的筛选及防治现状。现已知西花蓟马的寄生病原真菌有5种,包括蜡蚧轮枝菌(半知菌:丝孢目)、球孢白僵菌(半知菌:丝孢目)、金龟子绿僵菌(半知菌:丝孢目)、玫烟色棒束孢(半知菌:束梗孢目)和小孢新接霉。其中,球孢白僵菌、金龟子绿僵菌在西花蓟马的生物防治中应用最广,具有良好的开发应用潜力,部分防效好的虫生真菌已申请专利及实现工厂化生产。     

Entomopathogenic fungi in cornfields and their potential to manage larval western corn rootworm Diabrotica virgifera virgifera

Entomopathogenic ascomycete fungi are ubiquitous in soil and on phylloplanes, and are important natural enemies of many soil-borne arthropods including larval western corn rootworm, Diabrotica virgifera virgifera, which is a major pest of corn. We measured the prevalence of Beauveria bassiana and Metarhizium anisopliae sensu lato in ten cornfields in Iowa, USA by baiting with larval insects. B. bassiana and M. anisopliae s.l. were present in 60% ± 6.3% and 55% ± 6.4% of soil samples, respectively. Subsequent laboratory bioassays found that some M. anisopliae s.l. strains collected from cornfields killed a greater proportion of D.v. virgifera larvae than a standard commercial strain.     

Entomopathogenic fungi of Eurygaster integriceps Puton (Hemiptera: Scutelleridae): collection and characterization for development

Exploratory activities were done in Syria, Turkey, Iran, Uzbekistan, Kazakhstan, The Kyrghyz Republic, and Russia to locate entomopathogenic fungi of Eurygaster integriceps. Isolates from the entomopathogenic genera Beauveria, Paecilomyces, and Verticillium were collected. Beauveria bassiana was the most commonly recovered species. Thirty-one isolates of the 221 recovered were examined at 20, 25, 30, and 35 °C for 20 days for growth and sporulation. Growth and sporulation were generally highest at 25 °C. None of the isolates grew at 35 °C, and at 30 °C growth was retarded with no conidia being produced. Single- and multiple-concentration bioassays were conducted on greenhouse-grown wheat plants and in pine litter to evaluate virulence of fungi from several sources to E. integriceps. When tested at a single concentration, mortality after 15 days ranged from 66 to >95% in the litter assays and 50 to 91% in the plant assays. There was a distinct concentration response for most of the isolates tested in the multiple-concentration assay, particularly in the in-litter environment. In litter, mortality tended to develop earlier than in on-plant assays. Several isolates of B. bassiana and one Metarhizium anisopliae displayed consistently high virulence against E. integriceps and were more virulent than two commercial strains. Our results demonstrate the potential of entomopathogenic fungi for management of E. integriceps in overwintering sites and in wheat fields.     

Pathogenicity of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> and <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> to the tobacco spider mite <Emphasis Type="Italic">Tetranychus evansi</Emphasis>

Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and two isolates of Beauveria bassiana (Balsamo) Vuillemin were evaluated for their pathogenicity against the tobacco spider mite, Tetranychus evansi Baker & Pritchard. In the laboratory all the fungal isolates were pathogenic to the adult female mites, causing mortality between 22.1 and 82.6%. Isolates causing more than 70% mortality were subjected to dose–response mortality bioassays. The lethal concentration causing 50% mortality (LC₅₀) values ranged between 0.7×10⁷ and 2.5×10⁷ conidia ml⁻¹. The lethal time to 50% mortality (LT₅₀) values of the most active isolates of B. bassiana and M. anisopliae strains varied between 4.6 and 5.8 days. Potted tomato plants were artificially infested with T. evansi and treated with B. bassiana isolate GPK and M. anisopliae isolate ICIPE78. Both fungal isolates reduced the population density of mites as compared to untreated controls. However, conidia formulated in oil outperformed the ones formulated in water. This study demonstrates the prospects of pathogenic fungi for the management of T. evansi.     

Pathogenicity of hyphomycetous fungi against <Emphasis Type="Italic">Cyclocephala signaticollis</Emphasis>

Susceptibility of the white grub Cyclocephala signaticollis Burmeister (Coleoptera: Scarabaeidae: Dynastinae) larvae to seven isolates of Beauveria bassiana (Balsamo) Vuillemin, five of Metarhizium anisopliae (Metschnikoff) Sorokin and two of Paecilomyces lilacinus (Thom) Samson (Deuteromycotina: Hyphomycetes) was investigated. Among 14 fungal isolates screened the most virulent was a B. bassiana isolate (Bb 53) that caused 70% mortality of third instar larvae in 40 days after inoculation at 1 × 10⁸ conida/ml. Strains of M. anisopliae and P. lilacinus showed low efficacy or no virulence to the target host.     

Virulence of entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae against red palm weevil,Rhynchophorus ferrugineus (Olivier)

Nineteen different isolates of the entomopathogenic fungi Beauveria bassiana sensu lato (s.l.) and Metarhizium anisopliae s.l. (Ascomycota: Hypocreales), recovered from different soil samples (field crops, fruit orchards, vegetable fields and forests) and insect cadavers were tested against Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) at two different spore concentrations (1 × 10⁷ and 1 × 10⁸ conidia mL^?1). Three isolates of B. bassiana and two of M. anisopliae gave >88 % larval and >75 % adult mortality of R. ferrugineus on their highest dose rate respectively. More sporulating cadavers (mycosis) resulted from a high dose rate compared to low dose on both life stages of R. ferrugineus. The current study confirmed the lethal action of B. bassiana and M. anisopliae isolates with mortality levels usually directly proportional to the conidial concentration. This study further confirmed that the isolates recovered from R. ferrugineus dead cadavers gave more mortality compared to the other sources. In the virulence assay two isolates of B. bassiana caused the highest percentage of both larval and adult mortality at all exposure intervals which suggest that they may be the most promising for use in sustainable management programs aimed at microbial control in date palm orchards.     

Antagonism between entomopathogenic fungi and bacterial symbionts of entomopathogenic nematodes

Mutual effects between the symbiotic bacteria of entomopathogenic nematodes, Photorhabdus luminescens and Xenorhabdus poinarii, and entomopathogenic fungi were investigated in vitro. A dual culture assay on nutrient agar supplemented with bromothymol blue and triphenyltetrazolium chloride (NBTA) medium revealed that P. luminescens is antagonistic to Metarhizium anisopliae, Beauveria bassiana, B. brongniartii and Paecilomyces fumosoroseus by inhibiting their growth and conidial production; the fungal growth was not inhibited by X. poinarii. In a second laboratory experiment, crude extract produced by M. anisopliae was tested for its activity against P. luminescens and X. poinarii. Crude extract from M. anisopliae was antibacterial to P. luminescens and X. poinarii at 1000 g/ml and inhibited their growth on NBTA, but had no effect at 100 or 10 g/ml. The influence of the crude extract of M. anisopliae on the dispersal of infective juveniles (IJs) of Heterorhabditis megidis and Steinernema glaseri was assayed on Sabouraud Dextrose Agar (SDA) plates. Results showed that the crude extract of M. anisopliae had no toxic effects even at highest concentration (1000 g/ml).     

Relative susceptibility of <Emphasis Type="Italic">Spodoptera litura</Emphasis> pupae to selected entomopathogenic fungi

The pupae of Spodoptera litura (Fab.), (Lepidoptera: Noctuidae), a polyphagous pest affecting common crops in Indian subcontinent, were treated with different concentrations of conidia of four isolates of entomopathogenic fungi belonging to three species, Metarhizium anisopliae var. anisopliae (Metschnikov) Sorokin (ARSEF 7487), Lecanicillium muscarium (Petch) Zare & W Gams (two isolates ARSEF 7037 and ARSEF 6118) and Cordyceps cardinalis Sung & Spatafora (ARSEF 7193) under laboratory conditions. Suspensions (10⁸/ml) of conidia harvested from Sabouraud dextrose agar yeast extract (SDAY) plates resulted in the highest mortality (85.8%) with M. anisopliae and the lowest mortality (57.3%) with C. cardinalis. The values of LC₅₀ and LC₉₀ suggested that M. anisopliae was the most virulent fungal strain followed by L. muscarium (ARSEF 7037). However, C. cardinalis was the least virulent species among the fungi used in the bioassay. In soil bioassays, drenching the soil with conidial suspensions of ARSEF 7487 and ARSEF 7037 (10⁸ conidia/g of soil) reduced the adult emergence from pupa by 81.3% and 72.5%, respectively, while premixing the sterile soil with conidia killed lesser number of pupae (62.9% by ARSEF 7487 and 54.6% by ARSEF 7037). Our findings suggest that M. anisopliae (ARSEF 7487) and L. muscarium (ARSEF 7037) are potent entomopathogens and could be developed into biocontrol agents against rice cutworm in IPM programs. Handling editor: Helen Roy     

Interactions among the entomopathogenic fungus, Beauveria bassiana (Ascomycota: Hypocreales), the parasitoid, Aphidius matricariae (Hymenoptera: Braconidae), and its host, Myzus persicae (Homoptera: Aphididae)

The effect of the entomopathogenic fungus Beauveria bassiana on the biological characteristics and life table of Aphidius matricariae, a parasitoid of the green peach aphid, Myzus persicae, was studied under laboratory conditions. Aphids were first infected with twice the LC₉₅ of B. bassiana for third-instar M. persicae (2 × 10⁸ conidia/ml). Subsequently, at different intervals they were exposed to 1-day-old mated parasitoid females for 24 h. The number of mummies produced per female and the percentage emergence of the F1 generation differed significantly as a function of the time interval between application of the fungus and exposure to the parasitoid. The interference of B. bassiana on parasitoid development was also studied by first exposing the aphid hosts to the parasitoid for 24 h and subsequently applying B. bassiana. The number of mummies produced by a female A. matricariae varied from 11.8 to 24.8 and was significantly different when the aphids were first exposed to the parasitoids and then treated with B. bassiana 24, 48, 72, and 96 h after exposure. There were no significantly different effects of B. bassiana on net reproductive rate (R₀), mean generation time (T), intrinsic rate (r_m) and the finite rate of increase (λ) of A. matricariae as a result of development in hosts exposed to low or high conidial concentrations (1 × 10², 2 × 10⁸ conidia/ml). The parasitoids developed in infected hosts had lower r_m, λ, T and DT (doubling time) values compared with those that developed in uninfected hosts but no differences were observed in R₀ values. With proper timing, A. matricariae and B. bassiana can be used in combination in the successful biological control of M. persicae.     

Evaluation of the fungus Beauveria bassiana (Deuteromycotina: Hyphomycetes), a potential biological control agent of Lutzomyia longipalpis (Diptera, Psychodidae)

Visceral leishmaniasis is a zoonosis whose primary vector in Brazil is the sandfly Lutzomyia longipalpis Lutz & Neiva. Presently, efforts to control the vector have not been effective in reducing the prevalence of disease. A possible alternative to current strategies is the biological control of the vector using entomopathogenic fungi. This study evaluates the effects of the fungus, Beauveria bassiana (Bals.) Vuilleman, in different developmental stages of L. longipalpis. Five concentrations of the fungus were utilized ranging from 10⁴ to 10⁸ conidia/ml, with appropriate controls. The unhatched eggs, larvae and dead adults exposed to B. bassiana were sown to reisolate the fungus. The fungus was subsequently identified by polymerase chain reaction (PCR) and DNA sequencing. Exposure to B. bassiana reduced the number of eggs that hatched by 59% (P < 0.01). The longevity of infected adults was 5 days, significantly lower than that of the negative control which was 7 days (P < 0.001). The longevity of the adult sandfly exposed to the positive chemical (pyrethroid, cypermetherin) control was less than 1 day. The effects of fungal infection on the hatching of eggs laid by infected females were also significant and dose-dependent (P < 0.05). With respect to fungal post-infection growth parameters, only germination and sporulation were significantly higher than the fungi before infection (P < 0.001). The identity of the reisolated fungus was confirmed by automated DNA sequencing post-passage in all insect stages. These data show that B. bassiana has good pathogenic potential, primarily on L. longipalpis larvae and adults. Consequently, the use of this fungus in sandfly control programs has potential in reducing the use of chemical insecticides, resulting in benefits to humans and the environment.     

Virulence of entomopathogenic hypocrealean fungi infecting <Emphasis Type="Italic">Anoplophora glabripennis</Emphasis>

Twenty isolates of four species of entomopathogenic hypocrealean fungi (Beauveria bassiana, Beauveria brongniartii, Isaria farinosa, and Metarhizium anisopliae) were found to be pathogenic to adults of the Asian longhorned beetle, Anoplophora glabripennis. Survival times for 50% of the beetles tested (ST₅₀) ranged from 5.0 (M. anisopliae ARSEF 7234 and B. brongniartii ARSEF 6827) to 24.5 (I. farinosa ARSEF 8411) days. Screening studies initially included strains of B. brongniartii, which is registered as a microbial control agent in Europe, Asia and South America but not in North America. At that time, we could not confirm that this fungal species is native to North America which added uncertainty regarding future registration of this species for pest control in the USA. Therefore, subsequent bioassays documented median survival times for three M. anisopliae isolates (5–6 days to death) and two of these isolates are suggested for further development because they are already registered for pest control in the USA. An erratum to this article can be found at     

The effects of farming system,habitat type and bait type on the isolation of entomopathogenic fungi from citrus soils in the Eastern Cape Province,South Africa

A survey of occurrence of entomopathogenic fungi was undertaken on soils from citrus orchards and refugia on conventionally and organically managed farms in the Eastern Cape Province in South Africa. An adapted method for baiting soil samples with key citrus pest Thaumatotibia leucotreta (Meyrick; Lepidoptera: Tortricidae) and Ceratitis capitata (Wiedemann; Diptera: Tephritidae) larvae, as well as with the standard bait insect, Galleria mellonella (Linnaeus; Lepidoptera: Pyralidae), was implemented. Sixty-two potentially useful entomopathogenic fungal isolates belonging to four genera were collected from 288 soil samples, an occurrence frequency of 21.53%. The most frequently isolated entomopathogenic fungal species was Beauveria bassiana (Balsamo) Vuillemin (15.63%), followed by Metarhizium anisopliae var. anisopliae (Metschnikoff) Sorokin (3.82%). Galleria mellonella was the most effective bait insect used to isolate fungal species (χ ² = 40.13, df = 2, P ≤ 0.005), with a total of 45 isolates obtained, followed by C. capitata with 11 isolates, and T. leucotreta with six isolates recovered. There was a significantly (χ ² = 11.65, df = 1, P ≤ 0.005) higher occurrence of entomopathogenic fungi in soil samples taken from refugia compared to cultivated orchards of both organically and conventionally managed farms. No significant differences were observed in the recovery of fungal isolates when soil samples from both farming systems were compared.