Impacts of fungal entomopathogens on survival and immune responses of Aedes albopictus and Culex pipiens mosquitoes in the context of native Wolbachia infections

Microbial control of mosquitoes via the use of symbiotic or pathogenic microbes, such as Wolbachia and entomopathogenic fungi, are promising alternatives to synthetic insecticides to tackle the rapid increase in insecticide resistance and vector-borne disease outbreaks. This study evaluated the susceptibility and host responses of two important mosquito vectors, Ae. albopictus and Cx. pipiens, that naturally carry Wolbachia, to infections by entomopathogenic fungi. Our study indicated that while Wolbachia presence did not provide a protective advantage against entomopathogenic fungal infection, it nevertheless influenced the bacterial / fungal load and the expression of select anti-microbial effectors and phenoloxidase cascade genes in mosquitoes. Furthermore, although host responses from Ae. albopictus and Cx. pipiens were mostly similar, we observed contrasting phenotypes with regards to susceptibility and immune responses to fungal entomopathogenic infection in these two mosquitoes. This study provides new insights into the intricate multipartite interaction between the mosquito host, its native symbiont and pathogenic microbes that might be employed to control mosquito populations.     

Distribution and characterisation of entomopathogenic fungi from Korean soils

We investigated the occurrence of entomopathogenic fungi in 1080 soil samples representing multiple locations and conditions in Korea. Entomopathogenic fungi were isolated from soils using a selective medium containing dodine and antibiotics. Following an initial identification based on morphology, the fungal isolates were more precisely identified by the sequence of their nuclear ribosomal RNA (rRNA) internal transcribed spacer (ITS) regions. As a result, entomopathogenic fungi were found to occur in 32% (342 isolates) of the soil samples studied. The most abundant species were Beauveria spp. (125 isolates) and Metarhizium spp. (82 isolates). Entomopathogenic fungi were more often recovered from natural mountain and riparian soils than from agricultural habitats. The pathogenicity of isolated fungi was evaluated by using wax moth Galleria mellonella L. (Lepidoptera: Pyralidae) larvae. It was determined that 60% (207 isolates) of the isolates were pathogenic using this model. These entomopathogenic fungi may, therefore, have potential use against a variety of agricultural pests. This is the first study of the isolation and distribution of entomopathogenic fungi in representative sampling locations throughout Korea.     

Evaluation of entomopathogenic fungi as potential biological control agents of the dengue mosquito,Aedes aegypti (Diptera: Culicidae)

Dengue is a global health concern. Growing insecticide resistance in the primary mosquito vector, Aedes aegypti, limits the effectiveness of vector control, so alternative tools are urgently needed. One approach is the use of biopesticides comprising entomopathogenic fungi, e.g., Beauveria bassiana and Metarhizium anisopliae. These fungi may decrease disease transmission by reducing mosquito vector longevity and also occur worldwide, although many isolates have not been tested for virulence against mosquitoes. Ninety-three isolates of entomopathogenic fungi representing six species (B. bassiana, M. anisopliae, Isaria fumosorosea, I. farinosa, I. flavovirescens, and Lecanicillium spp.) were screened as potential biological control agents of Aedes aegypti. A hierarchical, multi-criteria experimental design was undertaken to find suitable isolates. Initial screening was performed via in vitro assays measuring radial growth and spore persistence, eliminating isolates with poor growth or viability on nutrient-rich substrate. Subsequent measurements of spore persistence revealed that only nine of 30 strains tested had half-lives exceeding 3 weeks. Ten isolates were chosen for in vivo bioassays against adult Ae. aegypti. From these assays, two Australian isolates of B. bassiana, FI-277 and FI-278, appeared to be most promising. Both isolates were shown to be virulent against Ae. aegypti at 20, 26, and 32°C. Spreading spores manually onto substrate was found to be more efficacious than spraying. Ae. aegypti infected by manually-spread spores on cotton substrate were found to have an LT₅₀ of 3.7±0.3 days. These characteristics suggest that FI-277 has promise as a dengue mosquito biocontrol agent, either alone or combined with conventional chemical insecticides.     

Susceptibility of adult Aedes aegypti (Diptera: Culicidae) to infection by Metarhizium anisopliae and Beauveria bassiana: prospects for Dengue vector control

Dengue fever vectored by the mosquito Aedes aegypti is one of the most rapidly spreading insect-borne diseases, stimulating the search for alternatives to current control methods. Screening assays using a range of Metarhizium anisopliae and Beauveria bassiana isolates were performed against adult female Ae. aegypti. Four virulent isolates were selected for detailed study. Adult female mosquitoes were exposed to supports previously inoculated with fungal suspensions. Fungal isolates were suspended in Tween 80+8% vegetable oil. The isolates caused between 70 and 89% mortality as a result of fungal infection over the 7-day test period. Mean survival times varied between 3 and 5 days for treated insects, whilst control survival exceeded 40 days. The most promising isolate, M. anisopliae LPP133, based not only on virulence but facility for mass production, was used for lethal exposure time determinations. An exposure time of only 3.5 h was necessary to cause 50% mortality. Large cage trails were also carried out and mean survival time of insects exposed to fungus impregnated black cloths was significantly reduced. These results show that entomopathogenic fungi could be promising biological control agents for use against adult Ae. aegypti, by inoculating fungi onto surfaces on which the mosquitoes tend to rest. The subsequent mortality caused by the fungi could potentially reduce the populations of this insect thus reducing the incidence of Dengue.     

New records of hypocrealean fungi infecting aphids and whiteflies: pathogenicity against Myzus persicae and interaction with its predator Eriopis connexa

Occurrence of hypocrealean entomopathogenic fungi in Argentina is reported. Bioassays were performed to evaluate their pathogenicity against Myzus persicae and Eriopis connexa. The findings underscore the importance of preserving these fungi and of investigating their potential for vector control.     

Virulence of entomopathogenic fungi isolated from wild mosquitoes against Aedes aegypti

The 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.     

Simple and rapid screening of entomopathogenic fungi having radical-scavenging and anticancer activities

Entomopathogenic fungal metabolites exhibit a wide variety of insecticidal, antimicrobial, anticancer, antioxidant, and antiviral activities, and they have been suggested as potential candidates for the development of new bioactive agents. The rapid and simple screening of entomopathogenic fungi with such bioactivities is important for investigating bioactive substances. The radical-scavenging and anticancer activities of 28 species and 20 genera of 342 isolates of entomopathogenic fungi were evaluated using only culture filtrates. As a result, 23 isolates of Metarhizium anisopliae var. anisopliae, 1 isolate of Pochonia sp., and 1 isolate of Aspergillus sp. showed high radical-scavenging activity. Additionally, anticancer activity in HCT116 human colon cancer cells was also confirmed for selected culture filtrates. This simple screening method of entomopathogenic fungi using culture filtrates may be useful for the rapid detection of related substances with pharmacological activity from a large number of fungal samples.     

Formulation of the entomopathogenic fungus Beauveria bassiana JN5R1W1 for the control of mosquito adults and evaluation of its novel applicability

In this study, an effective control agent and control technology for adult mosquitoes using entomopathogenic fungi is proposed as a solution to the adverse effects of chemical insecticides used for mosquito control. A formulation study was conducted using Beauveria bassiana JN5R1W1 with high virulence against both Aedes albopictus and Culex pipiens adult mosquitoes. For the inverted emulsion formulation, three kinds of vegetable oils were used to evaluate the germination promotion, UV blocking effects, and adhesion rate of conidia. As a result, soybean oil was selected as the most effective vegetable oil, and the corresponding formulation was made. Direct contact treatment of the inverted emulsion by spraying resulted in a mortality rate of approximately 100 % for both species of adult mosquitoes. However, in reality, since it is difficult to directly apply fungal agent treatment against adult mosquitoes, we evaluated a control method by indirect contact with mosquitoes after applying the inverted emulsion on a net. As an indirect treatment method, the prepared inverted emulsion showed a mortality rate of approximately 93 % or 89 % against Ae. albopictus and Cx. pipiens adult mosquitoes, respectively. Therefore, these results suggested that the inverted emulsion using B. bassiana JN5R1W1 is an effective control agent for controlling adult mosquitoes.     

Entomopathogen ID: a curated sequence resource for entomopathogenic fungi

We report the development of a publicly accessible, curated nucleotide sequence database of hypocrealean entomopathogenic fungi. The goal is to provide a platform for users to easily access sequence data from taxonomic reference strains. The database can be used to accurately identify unknown entomopathogenic fungi based on sequence data for a variety of phylogenetically informative loci. The database provides full multi-locus sequence alignment capabilities. The initial release contains data compiled for 525 strains covering the phylogenetic diversity of three important entomopathogenic families: Clavicipitaceae, Cordycipitaceae, and Ophiocordycipitaceae. Furthermore, Entomopathogen ID can be expanded to other fungal clades of insect pathogens, as sequence data becomes available. The database will allow isolate characterisation and evolutionary analyses. We contend that this freely available, web-accessible database will facilitate the broader community to accurately identify fungal entomopathogens, which will allow users to communicate research results more effectively.     

Environmental Isolates of Fungi from Aquarium Pools Housing Killer Whales (Orcinus orca)

Systemic mycoses in killer whales (Orcinus orca) are rare diseases, but have been reported. Two killer whales died by fungal infections at the Port of Nagoya Public Aquarium in Japan. In this study, the fungal flora of the pool environment at the aquarium was characterized. Alternaria spp., Aspergillus spp. (A. fumigatus, A. niger, A. versicolor), Fusarium spp. and Penicillium spp. were isolated from the air and the pool surroundings. The other isolates were identified as fungal species non-pathogenic for mammals. However, the species of fungi isolated from the environmental samples in this study were not the same as those isolated from the cases of disease in killer whales previously reported.     

Efficiency of fungus‐impregnated black cloths combined with Imidacloprid for the control of adult Aedes aegypti (Diptera: Culicidae)

Entomopathogenic fungi are potential candidates for use in integrated vector management. However, efficient delivery systems for these fungi need to be investigated. It is known that adult mosquitoes are attracted to dark surfaces, and therefore, black cotton cloths impregnated with Metarhizium anisopliae alone or in combination with the insecticide imidacloprid (IMI) were tested under laboratory conditions. Black cloths impregnated with fungus were also tested in large‐cage trials under natural extradomicile conditions. Blood‐fed Rockefeller and wild‐type strain Aedes aegypti had higher levels of survival when compared with sucrose‐fed counterparts following exposure to fungus‐impregnated cloths. However, when blood‐fed A. aegypti were exposed to a combination of M. anisopliae + IMI, the survival rates were statistically equal to those of sucrose‐fed females. Large‐cage trials showed significant decreases in A. aegypti survival following a minimum 12 h exposure of the mosquitoes to fungus‐impregnated cloths. Increased exposure times results in further reductions in survival. The synergism between M. anisopliae and IMI resulted in reduced survival rates independent of feeding regime under laboratory conditions. Fungus‐impregnated cloths tested under simulated field conditions, considered to be unfavourable for fungal infection, resulted in significant reductions in adult A. aegypti survival. We are currently testing the combined use of fungi and insecticides against blood‐fed insects under simulated field conditions.

Significance and Impact of the Study

The use of fungus‐impregnated cotton cloths is a promising point source application method for the control of adult Aedes aegypti, and this strategy could be incorporated into an integrated vector management programme aiming to reduce the incidence of dengue fever.     

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.     

CTC medium: A novel dodine-free selective medium for isolating entomopathogenic fungi,especially Metarhizium acridum,from soil

The selective media most commonly used for isolating hyphomycetous species of entomopathogenic fungi from non-sterile substrates rely on N-dodecylguanidine monoacetate (dodine) as the selective fungicide. Although these media are effective for isolating many species of Metarhizium and Beauveria from soil, they are inefficient media for isolation of an important Metarhizium species, Metarhizium acridum, from non-sterile soil. Our current study was directed to formulating a dodine-free selective medium that is efficient for isolating naturally occurring Beauveria spp. and Metarhizium spp., especially M. acridum, from soil. The selective medium (designated CTC medium) consists of potato dextrose agar plus yeast extract (PDAY) supplemented with chloramphenicol, thiabendazole and cycloheximide. In comparisons with selective media previously reported in the literature, the CTC medium afforded colonies that were larger and had both earlier and more abundant conidiation of entomopathogenic fungi, features which greatly facilitated identification of the emerging entomopathogenic fungi. In addition to efficient re-isolation of M. acridum, this medium also is an effective tool for selective isolation of Metarhizium brunneum, Metarhizium robertsii, Beauveria bassiana and Beauveria brongniartii from non-sterile field-collected soil samples inoculated (spiked) with fresh conidia in the laboratory.     

Isolation and identification of entomopathogenic fungus from Eastern Ghats of South Indian forest soil and their efficacy as biopesticide for mosquito control

The repeated usage of chemical insecticides, responsible for insecticide resistance in mosquitoes and environmental toxicity. Currently effective and environmental-safe control strategies are needed for the control disease-vector mosquitoes. Entomopathogens can be an effective alternative to chemical insecticide. Herein we isolated and tested 46 soil-borne entomopathogenic fungi belonging to six genera, namely Beauveria sp., Metarhizium sp., Fusarium sp., Aspergillus sp., Trichoderma sp., and Verticillium sp., fungi conidia were tested on Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus larvae. Bioassays results show that M. anisopliae fungal isolate causes a 100%, 98.6% and 92% mortality within six days, on Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus, respectively. M. anisopliae treated three mosquito larvae have lower lifetime with LT₅₀ values in A. stephensi, 2.931 days; A. aegypti, 2.676 days and C. quinquefasciatus, 3.254 days. 18 s rDNA sequence analysis confirmed that the isolated fungus are belonging to the genus of M. anisopliae-VKKH3, B. bassiana-VKBb03, and V. lecanii-VKPH1. Our results clearly show that M. anisopliae has good potential, as a low-cost, environmentally safe tool for the control of A. aegypti, A. stephensi, and C. quinquefasciatus mosquitoes.     

Management of pine wilt disease vectoring Monochamus alternatus adults using spray and soil application of Metarhizium anisopliae JEF isolates

Chemical control is widely used to control the Japanese pine sawyer beetle, Monochamus alternatus, but strong chemical regulations require an environmentally sound management strategy. In this work, we investigated the use of entomopathogenic fungi and their application as a means of practical pest management. Thirty-two diverse species of fungal isolates were assayed against adult pine sawyer beetles using a contact method under laboratory conditions, and four isolates showed over 70% virulence consequently. These isolates, two each of Beauveria bassiana and Metarhizium anisopliae were sprayed on the adult beetles at 1 × 10⁷ conidia/ml in plastic containers, respectively. The M. anisopliae-treated adult beetles showed 67% mortality. M. anisopliae isolates JEF-197 and JEF-279 demonstrated dosage-dependent insecticidal activity. Following the laboratory experiments, semi-field trials were conducted in young pine trees under high (RH 94%) and low (RH 35%) humidity conditions. In the high humidity conditions, most of the adult beetles stayed on the top of the branches. When the two M. anisopliae isolates were sprayed on the beetles, they showed ca. 50–70% insecticidal activity 11 days after application. In contrast, in low humidity conditions, the adult beetles tried to move off the branches and onto the soil. When the beetles reached the JEF-197 and JEF-279-treated soil, we measured >90% insecticidal activity. This work suggests that M. anisopliae was the most virulent entomopathogenic fungus against adult Japanese pine sawyer beetles, and this forest insect could be ecologically controlled by the spray and soil application of the M. anisopliae isolates.     

Distribution,occurrence and natural invertebrate hosts of indigenous entomopathogenic fungi of Central India

We report here that, during periodical surveys of insects inhabiting diverse habitats for the collection of entomopathogenic fungi; a large number of isolates were recovered belonging to seven species, from various regions of Madhya Pradesh and Chhattisgarh forest areas and agricultural fields. The most common entomopathogenic fungi such as Beauveria bassiana, Nomuraea rileyi, Paecilomyces farinosus and Paecilomyces fumosoroseus were found to infect various insect hosts species naturally viz. Hyblaea puera, Eutectona machaeralis, Diachrysia orichalcea, Spodoptera litura, and few new insect hosts of these fungal pathogens among Indian insect population were collected for the first time from Central India, such as beetles of Agrilus species, hairy caterpillars of Lymantria species. The isolation, identification, maintenance and pathogenicity assay of these isolates was performed prior to deposition in culture collection center.     

Cold activity of Beauveria and Metarhizium, and thermotolerance of Beauveria

Heat and cold are environmental abiotic factors that restrict the use of entomopathogenic fungi as agents for biological control of insects. The thermotolerance and cold activity of 60 entomopathogenic fungal isolates, including five species of Beauveria and one isolate of Engyodontium albus (=Beauveria alba) were examined as to tolerance of temperatures that might be encountered during field use. In addition, cold activity of eight Metarhizium spp. isolates was evaluated. The isolates were from various geographic regions, arthropod hosts or substrates. High variability in conidial thermotolerance was found among the Beauveria spp. isolates after exposure to 45 °C for 2 h, as evidenced by low (0-20%), medium (20-60%), or high germination (60-80%). The thermal death point (0% germination) for three rather thermotolerant B. bassiana isolates (CG 138, GHA and ARSEF 252) was 46 °C for 6 h. At low temperatures (5 °C), with few exceptions (e.g. CG 66, UFPE 479, CG 227, CG 02), most of the B. bassiana isolates germinated well (ca. 100%). On the other hand, only one isolate of Metarhizium sp. was cold-active (i.e. ARSEF 4343 from Macquarie Island, 54.4°S, Australia). This probably is a M. frigidum isolate. The E. albus isolate (UFPE 3138) was the most susceptible isolate to both heat and cold stress. Isolates ARSEF 252 and GHA of B. bassiana, on the other hand, presented exceptionally high thermotolerance and cold activity. Some isolates with high cold activity, however, were thermosensitive (e.g. ARSEF 1682) and others with high thermotolerance had low cold activity (e.g. CG 227). An attempt to correlate the latitude of origin with thermotolerance or cold activity indicated that B. bassiana isolates from higher latitudes were more cold-active than isolates from nearer the equator, but there was not a similar correlation for heat.     

Evaluation of in vitro activities of extracellular enzymes from Aspergillus species isolated from corneal ulcer/keratitis

Mycotic/fungal keratitis is a suppurative, generally ulcerative infection of the cornea. The filamentous fungi, Aspergillus spp. are the second leading cause of mycotic keratitis, particularly in India. Aspergillus spp. produce a range of extracellular enzymes that are used to break down complex molecules and used for growth and reproduction, also for survival on/in host organism. The current study was designed with an objective to screen in vitro extracellular enzyme activity of Fusarium and Aspergillus isolates from mycotic keratitis patients and to correlate the same as a putative virulence factor. Extracellular enzymes viz., deoxyribonuclease (DNase), protease, lipase, elastase, keratinase, etc., produced by Aspergillus have key role in keratomycosis and hence their (n = 85) in vitro activities were investigated. It was found that, the majority of the Aspergillus isolates produced protease (n = 75; 88% of 85) followed by lipase (n = 59; 69% of 85), DNase (n = 35; 41% of 85), elastase (n = 26; 31% of 85) and keratinase (n = 13; 15% of 85). The enzyme activity indices (EAI) for DNase, elastase, protease and lipase ranged between 1.01 and 1.98, whereas elastase EAI varied between 1.26 and 1.92. DNase, protease and lipase showed a maximum EAI of 1.98 and lowest EAI value of 1.01, respectively. Extracellular enzymes of Aspergillus spp. may have potential role in the onset and progression of keratitis.     

Entomopathogenic fungi as biological control agents for the vector of the laurel wilt disease,the redbay ambrosia beetle,Xyleborus glabratus (Coleoptera: Curculionidae)

The redbay ambrosia beetle (RAB), Xyleborus glabratus, is a wood-boring insect that vectors the fungal pathogen, Raffaelea lauricola, which causes laurel wilt, a lethal disease of avocado. The objective of this study was to determine the susceptibility of RAB to infection and subsequent death by exposure to three commercial strains of entomopathogenic fungi [two strains of Isaria fumosorosea (Ifr 3581 and PFR), and strain GHA of Beauveria bassiana]. RAB females were dipped in fungal spore solutions and their median survivorship times (MST) determined. Contact with any of the biopesticides resulted in death of all RAB females. MSTs of RAB females ranged from 3 days (B. bassiana) to 5 days (I. fumosorosea PFR). B. bassiana killed RAB females faster, followed by Ifr 3581 and PFR. RAB females dipped in B. bassiana suspensions had the highest number of viable spores attached to their bodies, followed by Ifr 3581. Beetles dipped in PFR suspension had significantly less viable spores attached to their bodies. No significant differences were observed in the mortality of beetles exposed to entomopathogenic fungi by dipping in a fungal suspension or walking on treated avocado bolts. Beetles bored into the logs and constructed galleries, but they were found dead inside the galleries a few days after exposure to the entomopathogens. Entomopathogenic fungal infection in dead beetles was confirmed through molecular techniques. This is the first study to demonstrate that entomopathogenic fungi are potential biological control agents against RAB.     

Lethal and pre-lethal effects of a fungal biopesticide contribute to substantial and rapid control of malaria vectors

Rapidly emerging insecticide resistance is creating an urgent need for new active ingredients to control the adult mosquitoes that vector malaria. Biopesticides based on the spores of entomopathogenic fungi have shown considerable promise by causing very substantial mortality within 7-14 days of exposure. This mortality will generate excellent malaria control if there is a high likelihood that mosquitoes contact fungi early in their adult lives. However, where contact rates are lower, as might result from poor pesticide coverage, some mosquitoes will contact fungi one or more feeding cycles after they acquire malaria, and so risk transmitting malaria before the fungus kills them. Critics have argued that 'slow acting' fungal biopesticides are, therefore, incapable of delivering malaria control in real-world contexts. Here, utilizing standard WHO laboratory protocols, we demonstrate effective action of a biopesticide much faster than previously reported. Specifically, we show that transient exposure to clay tiles sprayed with a candidate biopesticide comprising spores of a natural isolate of Beauveria bassiana, could reduce malaria transmission potential to zero within a feeding cycle. The effect resulted from a combination of high mortality and rapid fungal-induced reduction in feeding and flight capacity. Additionally, multiple insecticide-resistant lines from three key African malaria vector species were completely susceptible to fungus. Thus, fungal biopesticides can block transmission on a par with chemical insecticides, and can achieve this where chemical insecticides have little impact. These results support broadening the current vector control paradigm beyond fast-acting chemical toxins.