RESUMO
BACKGROUND: Ticks are obligate bloodsucking parasites responsible for significant economic losses and concerns with human and animal health, mainly due to the transmission of pathogens. Entomopathogenic fungi have been intensively studied as an alternative strategy for tick control that can be used in combination with synthetic acaricides in the integrated management of ticks. Here, we investigated how the gut bacterial community of Rhipicephalus microplus is shaped after Metarhizium anisopliae treatment and how the tick susceptibility to the fungus is affected after disrupting gut bacterial microbiota. METHODS: Partially engorged tick females were artificially fed with pure bovine blood or blood plus tetracycline. Two other groups received the same diet and were topically treated with M. anisopliae. The guts were dissected, and the genomic DNA was extracted 3 days after the treatment; the V3-V4 variable region of the bacterial 16S rRNA gene was amplified. RESULTS: The gut of ticks that received no antibiotic but were treated with M. anisopliae exhibited lower bacterial diversity and a higher occurrence of Coxiella species. The Simpson diversity index and Pielou equability coefficient were higher in the gut bacterial community when R. microplus were fed with tetracycline and fungus-treated. Ticks from fungus-treated groups (with or without tetracycline) exhibited lower survival than untreated females. Previous feeding of ticks with the antibiotic did not change their susceptibility to the fungus. Ehrlichia spp. were not detected in the gueated groups. CONCLUSIONS: These findings suggest that myco-acaricidal action would not be impacted if the calf hosting these ticks is under antibiotic therapy. Moreover, the hypothesis that entomopathogenic fungi can affect the bacterial community in the gut of R. microplus engorged females is endorsed by the fact that ticks exposed to M. anisopliae exhibited a dramatic reduction in bacterial diversity. This is the first report of an entomopathogenic fungus affecting the tick gut microbiota.
Assuntos
Acaricidas , Microbioma Gastrointestinal , Metarhizium , Rhipicephalus , Feminino , Humanos , Animais , Bovinos , Rhipicephalus/microbiologia , RNA Ribossômico 16S/genética , Controle Biológico de Vetores , Tetraciclina , Antibacterianos/farmacologiaRESUMO
A new species from the fungal genus Tolypocladium (Hypocreales: Ophiocordycipitaceae) that infects Stratiomyidae larva from the genus Hylorops is described: Tolypocladium valdiviae Gallardo-Pillancari, Montalva & González. The description is based on both genomic data and morphological characteristics. The sexual stage of T. valdiviae presents fleshy and visible stromata; unlike Tolypocladium ophioglossoides, it is smaller and emerges directly from its host and resembles Tolypocladium longisegmentis and Tolypocladium capitatum, both of which are parasites of deer truffle fungi of the genus Elaphomyces (Ascomycota: Eurotiales). In the anamorphic state, T. valdiviae presents conidiogenous cells similar in shape and arrangement to those of Tolypocladium inflatum, however T. valdiviae produces larger conidiogenous cells and, occasionally, produces chlamydospores. Phylogenetic evidence suggested that T. valdiviae is in a clade close to T. longisegmentis, T. inflatum and T. ophioglossoides, species also recognized to be parasites of fungi of the genus Elaphomyces. The new species is known so far only from Valdivia, southern Chile.
Assuntos
Dípteros , Hypocreales , Animais , Larva , Filogenia , Chile , Hypocreales/genéticaRESUMO
Aedes aegypti (Linnaeus, 1762) is an important vector of arboviruses in the tropics and subtropics. New control strategies based on natural enemies such as entomopathogenic fungi are of utmost importance, and the present study reports the first isolation of Clonostachys spp. (Hypocreales: Bionectriaceae) from mosquitoes and their activity against A. aegypti. Entomopathogenic fungi were surveyed in central Brazil using A. aegypti larvae as sentinels and, also, a CDC light trap. Clonostachys eriocamporesii R.H. Perera & K.D. Hyde, 2020 (IP 440) and Clonostachys byssicola Schroers, 2001 (IP 461) were identified by sequence analysis of the nuclear ribosomal internal transcribed spacer gene, and tested against eggs, larvae, and adults. Both strains were highly active against A. aegypti third instar larvae, with mortalities ≥ 80% at 107 conidia/mL after 5 days but distinctly less active against eggs and adults. This is the first report of both C. eriocamporesii and C. byssicola as naturally occurring pathogens affecting mosquitoes, and IP 440 appears to be a promising control agent against aquatic stages of A. aegypti.
Assuntos
Aedes , Hypocreales , Aedes/microbiologia , Animais , Larva/microbiologia , Controle de Mosquitos , Mosquitos Vetores , Esporos FúngicosRESUMO
Collecting entomopathogenic fungi associated with mosquitoes and studies on their activity against mosquito developmental stages will improve the understanding of their potential as agents to control important mosquito vectors. Twenty-one strains of entomopathogenic fungi affecting mosquitoes in Central Brazil were studied: 7 of Beauveria bassiana, 7 of Metarhizium humberi, 3 of M. anisopliae, 2 of Cordyceps sp. and one each of Akanthomyces saksenae and Simplicillium lamellicola. These fungi were isolated from field-collected mosquito adults (3 strains) or larvae (a single strain); the other 17 strains were isolated from laboratory-reared Aedes aegypti sentinel larvae set out in partially immersed cages placed in diverse small- to middle-sized aquatic mosquito habitats in or close to areas with secondary tropical forest. The frequent recovery of normally soil-borne Metarhizium spp. and B. bassiana from aquatic habitats is notable. Our laboratory findings indicated that M. anisopliae IP 429 and IP 438 and M. humberi IP 421 and IP 478 were highly active against immature stages and, together with M. anisopliae IP 432, also against adults. These strains appear to be the most promising candidates to develop effective control strategies targeting the different developmental stages of A. aegypti, the most important vector of viral diseases in humans in the tropics.
Assuntos
Aedes , Beauveria , Metarhizium , Aedes/microbiologia , Animais , Brasil , Ecossistema , Humanos , Larva , Controle de Mosquitos , Controle Biológico de Vetores , SoloRESUMO
Musca domestica L. is a cosmopolitan nuisance of high sanitary importance. Entomopathogenic fungi are innovative and attractive tools for integrated control of the housefly to overcome insufficient levels of control caused by increasing resistance of this pest against chemical insecticides. High virulence of a fungal strain is a prerequisite to develop a mycoinsecticide, and the present study investigated the potential of hypocrealean fungi from the genera Beauveria, Clonostachys, Cordyceps, Akanthomyces, Metarhizium, and Tolypocladium, isolated from mosquitoes in Central Brazil against M. domestica. The highest mortalities (larvae, pupae, and adults) were caused by Metarhizium humberi IP 478 (98%) and IP 421 (90%), Metarhizium anisopliae IP 432 (85%), Beauveria bassiana IP 433 (82%), and Tolypocladium cylindrosporum IP 425 (68%) after a 23-day exposure of initially pre-pupating third instar larvae to conidia mixed with vermiculite. Lethal concentrations to kill 90% of adults of IP 433 and IP 478 were 5 × 107 and 108 conidia g-1 substrate, respectively. Fifty percent of adults were killed within 4 to 5 days of exposure initially as pupae close to emergence to substrate treated with conidia of IP 478 or IP 433 at 1.1 × 108 conidia g-1, respectively. The other fungal strains tested were less virulent. The results demonstrate high potentials for conidial preparations in vermiculite of IP 433 and IP 478 as candidates for the biological control of both pre-pupating larvae, pupae, and emerging adults of houseflies.
Assuntos
Beauveria , Moscas Domésticas , Metarhizium , Silicatos de Alumínio , Animais , Brasil , Larva/microbiologia , Controle Biológico de Vetores , Esporos FúngicosRESUMO
Entomopathogenic fungi can achieve important innovative outcomes for integrated mosquito control especially of Aedes aegypti, the key vector of arboviruses to humans in the tropics and subtropics. This study sought to design and to develop a simple dissemination device to attract and to infect gravid A. aegypti adults with a granular formulation of the ascomycete Metarhizium humberi IP 46, and to validate this device in the laboratory as well as in semi-field and field conditions. Hydrogel (polyacrylamide potassium polyacrylate) was confirmed to be a suitable substitute for water used in the device that attracted gravid females under field conditions. Females laid eggs on black polyethylene terephthalate carpet fixed in the device that also proved to be a suitable substrate for a granular formulation of fungal microsclerotia and/or conidia. The plastic device (29.5 cm high) was divided into a lower closed compartment with a water reservoir and an upper, laterally open but covered compartment with continuously hydrated gel and the fungal formulation attached to the carpet. The uppermost compartment permitted free circulation of mosquito adults. The device attracted both male and female A. aegypti. The fungal formulations of IP 46 propagules tested in the device were effective against adults in laboratory, semi-field, and field settings. Findings in the laboratory, semi-field, and especially in field conditions strengthen the value and utility of this innovative device for focal applications of a mycoinsecticide against this important mosquito vector.Key points⢠Low-cost and simple disseminating device for focal control of Aedes aegypti.⢠Granulized Metarhizium humberi IP 46 and hydrogel yield extended control.⢠Findings in field tests strengthen benefit of the device for focal application.
Assuntos
Aedes , Metarhizium , Animais , Brasil , Feminino , Humanos , Masculino , Mosquitos VetoresRESUMO
Granular microsclerotial formulations of entomopathogenic fungi deserve attention because of their post-application, in situ production of new conidia that enhance and prolong mycoinsecticidal efficacy against a target pest insect. Because high ambient moisture is a crucial condition to induce fungal development and conidiogenesis on granules, we tested the impacts of the additions of three humectants-glycerin, propylene glycol, and polyethylene glycol 400-on water absorption by pellets incorporating microsclerotia of Metarhizium humberi IP 46 with microcrystalline cellulose or vermiculite carriers, and on the production of infective conidia of IP 46 microsclerotia in ambient humidities suboptimal for routine conidiogenesis. Glycerin facilitated greater and faster absorption of water than the other humectants. Microcrystalline cellulose absorbed low quantities of water without any added humectant whereas vermiculite did not. IP 46 did not grow or sporulate on pellets prepared with or without glycerin at 86% relative humidity (RH) or on control pellets without glycerin at 91% RH; conidial production on pellets prepared with vermiculite or microcrystalline cellulose and 10% glycerin reached 1.1 × 105 conidia/mg and 1 × 105 conidia/mg, respectively, after 20 days of exposure at 91% RH. Hence, these results strongly support glycerin as a suitable humectant for granular microsclerotial formulations of this fungus.
Assuntos
Higroscópicos/farmacologia , Metarhizium/efeitos dos fármacos , Metarhizium/fisiologia , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento , Glicerol/farmacologia , Higroscópicos/classificação , Controle Biológico de Vetores , Propilenoglicol/farmacologia , Água/metabolismoRESUMO
Entomopathogenic fungi are important agents for mosquito vector control. We report on the utility of a simple method to detect fungi on living larvae of Aedes aegypti that had been exposed to a fungal entomopathogen. Four species of the hypocrealean genera Metarhizium, Beauveria, Tolypocladium and Culicinomyces, known for their larvicidal activity against mosquito species, were tested. Living larvae previously exposed to a suspension of different conidial concentrations were set directly into the surface water film on non-nutritive agar supplemented with chloramphenicol, thiabendazole and crystal violet and then incubated. Except for C. clavisporus ARSEF 964 (which developed and produced conidia mostly inside the cadaver rather than on its surface in the present study), this method favored external fungal development and conidiogenesis on larvae of different instars after death. The dead larva on the water agar represents the unique and specific source of nutrition for the fungus that killed it. The technique facilitates the detection and posterior isolation of entomopathogenic fungi, and offers a compact, convenient, and rapid means to survey larval mosquito populations for fungal pathogens at the field.
Assuntos
Aedes/microbiologia , Entomologia/métodos , Hypocreales/isolamento & purificação , Controle de Mosquitos/métodos , Parasitologia/métodos , Aedes/crescimento & desenvolvimento , Animais , Beauveria/isolamento & purificação , Larva/crescimento & desenvolvimento , Larva/microbiologia , Metarhizium/isolamento & purificaçãoRESUMO
The impact of ambient relative humidity (RH) on conidial production of Metarhizium humberi IP 46 microsclerotia (MS) formulated in pellets or granules was investigated, and a promising granular formulation was tested against Aedes aegypti adults to confirm its efficacy. Microcrystalline cellulose (MC) and diatomaceous earth (DE) or a combination of vermiculite (VE), DE and silicon dioxide (SD) were tested as carriers in granular formulations containing MS. A range of 93-96.5% RH was critical for fungal development, and at least 96.5-98.5% RH was required for high conidial production on pellets or granules. Conidial production was clearly higher on pellets and granules prepared with VE than MC as the main carrier. VE granules containing MS were highly active against A. aegypti adults. Most mosquitoes were killed within 6 days after treatment regardless of the exposure time of adults to the formulation (1 min-24 h) or ambient humidity (75 or >98%). Production of conidia on dead adults varied between 7.3 × 106 and 2.2 × 107 conidia/individual, when exposed to MS granules for 12 h and 1 min, respectively. Granular formulations containing VE as the main carrier and MS as the active ingredient of M. humberi have strong potential for use against A. aegypti. KEY POINTS: ⢠High conidial production on granular microsclerotial formulations at >96.5% RH ⢠Vermiculite is more appropriate as a carrier than microcrystalline cellulose ⢠Granules with IP 46 microsclerotia are highly active against Aedes aegypti adults.
Assuntos
Aedes , Metarhizium , Animais , Umidade , Larva , Controle Biológico de VetoresRESUMO
We combined matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) along with sequencing of the B locus intergenic region (Bloc) to assess the diversity of Brazilian species within the anamorphic genus Beauveria. A total of 121 strains maintained in a government-owned culture collection and isolated from a range of hosts/substrates over a long time span (1981-2015) were assessed. Strains were collected in five of six Brazilian biomes, mostly in the Atlantic Forest (42.2%) and Cerrado (29.8%), primarily from insect pests of crops. All strains were subjected to MS, and those not accurately identified by this technique were genomically analyzed. Among the outcomes of this study, four taxa from the genus Beauveria were recognized, with the great majority of strains belonging to B. bassiana s.str. (93.4%), followed by B. caledonica (2.5%), B. pseudobassiana (2.5%) and B. amorpha (1.6%). B. bassiana s.str. was found in all biomes and isolated from a wide range of hosts/substrates. Due to low numbers, associations of the remaining Beauveria species with specific hosts or habitats/biomes were not clear, except that all three B. caledonica strains were found only in the Cerrado biome and were associated with adults of the banana weevil, Cosmopolites sordidus (Col.:Curculionidae). B. pseudobassiana is reported for the first time on the South American continent, in a subtropical region and from two insect orders not yet associated with this taxon. We also showed that some strains previously ascribed to B. brongniartii were misidentifications. The biodiversity of Beauveria analyzed in our study was comparatively low. The geographic origins of strains used in our study were biased towards biomes with intense human interventions. Future surveys on more conserved, less environmentally disturbed biomes, such as Caatinga, Pampa, Pantanal, and Amazon are needed for a more comprehensive picture of the diversity of Beauveria and related genera in Brazil.
Assuntos
Beauveria/classificação , Interações Hospedeiro-Patógeno , Micobioma , Beauveria/genética , Brasil , DNA Fúngico/análise , DNA Intergênico/análise , Filogenia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
The aquatic fungal genus Culicinomyces attacks dipteran larvae but little is known about its efficacy against Aedes aegypti. Here we report on the activity of both described species-Culicinomyces clavisporus and Culicinomyces bisporalis-on larvae, eggs and adults, and on trans-stadial transmission. Ten C. clavisporus isolates (ARSEF 372, 582, 644, 706, 964, 1260, 2471, 2478, 2479 and 2480) and C. bisporalis ARSEF 1948 were screened against larvae of this important vector of viral diseases. ARSEF 644, 964 and 2479 had the lowest LC50 (≤3.6â¯×â¯105â¯conidia/ml) after a 3-day exposure and shortest LT50 (≤1.3â¯days) at 106â¯conidia/ml against larvae; none of these isolates affected either eggs or adults treated topically with conidia. However, adults fed on a conidial (106â¯conidia/ml) suspension in 10% sucrose died (≤26.6⯱â¯3.3% mortality, 5â¯days after feeding) but no fungal development was detected on dead adults. No pupae or adults obtained following treatment of fourth instar larvae with 105 or 106â¯conidia/ml showed any indication of fungal presence. C. clavisporus-especially ARSEF 644, 964 and 2479-is the first choice for control of A. aegypti and has high potential in control strategies targeting aquatic larvae.
Assuntos
Aedes/parasitologia , Hypocreales , Larva/parasitologia , Controle de Mosquitos/métodos , Controle Biológico de Vetores/métodos , Animais , Óvulo/parasitologiaRESUMO
Pythium insidiosum is a straminopilan pathogen causing life threatening infections in mammals inhabiting temperate, tropical and subtropical areas of the world. The concept that P. insidiosum could also infect mosquitoes was mentioned earlier by investigators conducting phylogenetic analysis on available P. insidiosum isolates deposited at different culture collections. However, an official report and details on its pathological features in mosquitoes are not available. We are reporting the isolation of P. insidiosum from infected mosquito larvae during a survey conducted in central Brazil. At least three oomycotan isolates were recovered during the survey. Due to their ability to infect mosquito larvae the isolates were deposited in the U.S. Department of Agriculture, Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF; Ithaca, New York) as putative Lagenidium species. The investigated isolates developed very well at 37⯰C, produced typical Pythium-like vesicles containing numerous biflagellate zoospores, hydrolyzed sucrose, and their cultured extracted proteins were recognized in serological analysis by anti-P. insidiosum antibodies. Phylogenetic analyses using ITS and partial COXII DNA sequences identified the isolates as P. insidiosum within the American Cluster I. This is the first official report of P. insidiosum recovered from infected mosquito larvae, indicating that this mammalian pathogen, in addition to plants, it could also use mosquito larvae to complete its life cycle in nature.
Assuntos
Culicidae/parasitologia , Pythium/isolamento & purificação , Animais , Brasil , Larva/parasitologia , Filogenia , Pythium/classificação , Pythium/genética , Análise de Sequência de DNARESUMO
A strain within the Metarhizium anisopliae species complex was isolated in 2009 from a soil sample in a banana plantation in the municipality of Quixeré, Northeastern region of Brazil. Previous studies showed that this insect-pathogenic strain does not fit with any current taxon within the M. anisopliae species complex, as determined by both genomic and by mass spectrometric analyses. In the present study, CG1123 (=ARSEF 13308) is shown to be morphologically indistinguishable from most species in this cosmopolitan species complex, whereas multilocus phylogeny confirmed its uniqueness and supports its recognition as a new species, Metarhizium alvesii, in honor of Sérgio Batista Alves, one of the founders of insect pathology in Brazil.
Assuntos
DNA Fúngico/genética , Metarhizium/genética , DNA Fúngico/análise , Filogenia , Análise de Sequência de DNARESUMO
The current study investigated the thermotolerance of Metarhizium anisopliae s.l. conidia from the commercial products Metarril® SP Organic and Metarril® WP. The efficacy of these M. anisopliae formulations against the tick Rhipicephalus sanguineus s.l. was studied in laboratory under optimum or heat-stress conditions. The products were prepared in water [Tween® 80, 0.01 % (v/v)] or pure mineral oil. Conidia from Metarril® SP Organic suspended in water presented markedly delayed germination after heating to constant 40 °C (for 2, 4, or 6 h) compared to conidia suspended in mineral oil. Metarril® SP Organic suspended in oil and exposed to daily cycles of heat-stress (40 °C for 4 h and 25 °C for 19 h for 5 consecutive days) presented relative germination of conidia ranging from 92.8 to 87.2 % from day 1 to day 5, respectively. Conversely, germination of conidia prepared in water ranged from 79.3 to 39.1 % from day 1 to day 5, respectively. Culturability of Metarril® WP decreased from 96 % when conidia were cultured for 30 min prior to heat exposure (40 °C for 4 h) to 9 % when conidia were cultured for 8 h. Tick percent control was distinctly higher when engorged females were treated with oil suspensions rather than water suspensions, even when treated ticks were exposed to heat-stress regimen. Oil-based applications protected fungal conidia against heat-stress. Although Metarril® is not registered for tick control, it may be useful for controlling R. sanguineus, especially if it is prepared in mineral oil.
Assuntos
Metarhizium/crescimento & desenvolvimento , Controle Biológico de Vetores/métodos , Rhipicephalus sanguineus/microbiologia , Controle de Ácaros e Carrapatos/métodos , Animais , Feminino , Temperatura Alta , Metarhizium/patogenicidade , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/patogenicidade , VirulênciaRESUMO
The exotic bagrada bug or painted bug, Bagrada hilaris, and the native potato/tomato psyllid, Bactericera (=Paratrioza) cockerelli, are key pests of horticulture in western North America. In 2014-2015, adult and juvenile B. hilaris and B. cockerelli killed by fungi in the genus Zoophthora were detected near Saltillo, northeastern Mexico. We report the field prevalence and observations of Zoophthora on these hosts. The morphology and growth characteristics of field-collected specimens and pure in vitro cultures, as well as molecular markers (ITS1 and ITS4) were analyzed to identify these Zoophthora populations. Although there were morphological spore differences detected among field collections from both insect hosts, the fungi causing these mycoses can be identified as the same species (Zoophthora radicans), according to morphometric data from in vitro cultures (where differences observed in field material were attenuated) and sequence data (96-99% identity for ITS1 and 4). These results underscore the plasticity of field collections and in vitro cultures, and the relevance of comprehensive morphological and molecular analysis from cultures under standard conditions. Dose-response bioassays were conducted with one Z. radicans strain against bagrada bug nymphs. Exposure to conidial showers from cultures induced 30-90% mortality. This is the first report of a natural enemy of bagrada bug in Mexico, and the first published report of entomophthoralean fungi naturally attacking bagrada bugs and potato psyllids. Z. radicans should be further investigated as a tool in the biological control of hemipterans.
Assuntos
Hemípteros/parasitologia , Controle Biológico de Vetores/métodos , Zigomicose/veterinária , Animais , Entomophthorales/patogenicidade , México , Prevalência , VirulênciaRESUMO
A new fungal pathogen of Culicinae (Diptera: Culicidae) adults, Conidiobolus macrosporus (Entomophthorales: Ancylistaceae), was detected and isolated during a survey of mosquito pathogens close to the city of Aruanã, Goiás State, in December 2014. The morphological characteristics of C. macrosporus are presented, and reasons for some uncertainty about this identification are discussed. The pathogenicity and high virulence of this fungus for Aedes aegypti were confirmed in laboratory conditions. Mortality of adults exposed to conidia was observed within 24h of exposure to the pathogen, and increased to 100% as quickly as 3days after inoculation (with the highest conidial concentration tested, 8.3×10(4)conidia/cm(2)). Repeated attempts to obtain genomic sequence data failed despite confirmations that the DNA extraction methods were themselves successful.
Assuntos
Aedes/parasitologia , Conidiobolus/genética , Conidiobolus/patogenicidade , Zigomicose/veterinária , Animais , Brasil , Controle de Mosquitos/métodos , Controle Biológico de Vetores/métodos , VirulênciaRESUMO
We describe symptoms of mycosis induced by two native fungal entomopathogens of the citrus orthezia scale, Praelongorthezia praelonga (Hemiptera: Ortheziidae), an important pest of citrus orchards. The data presented in this article are related to the article entitled "Seasonal prevalence of the insect pathogenic fungus Colletotrichum nymphaeae in Brazilian citrus groves under different chemical pesticide regimes" [1]. The endemic fungal pathogen, C. nymphaeae, emerges through the thin cuticular intersegmental regions of the citrus orthezia scale body revealing orange salmon-pigmented conidiophores bearing conidial masses, as well as producing rhizoid-like hyphae that extend over the citrus leaf. By contrast, nymphs or adult females of this scale insect infected with Lecanicillium longisporum exhibit profuse outgrowth of bright white-pigmented conidiophores with clusters of conidia emerging from the insect intersegmental membranes, and mycosed cadavers are commonly observed attached to the leaf surface by hyphal extensions. These morphological differences are important features to discriminate these fungal entomopathogens in citrus orthezia scales.
RESUMO
A wild, forest-dwelling cockroach from the subfamily Ectobiidae (order Blattodea) in a nature reserve in Cavalcante, in the state of Goiás, Brazil, was found to be infected by a new, genetically distinct species in the Metarhizium flavoviride species complex that we describe here as Metarhizium blattodeae. The status of this fungus as a new species is supported by both multigenic sequence comparisons and protein profiles generated by MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry. This is one of the first reports of a naturally occurring fungal pathogen affecting any sylvatic (forest-dwelling) cockroach from any part of the world. M. blattodeae caused up to 96 % mortality of Periplaneta americana nymphs (a serious peridomestic cockroach species) after 10 d.
Assuntos
Blattellidae/microbiologia , Metarhizium/classificação , Metarhizium/isolamento & purificação , Micoses/microbiologia , Animais , Brasil , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Proteínas Fúngicas/análise , Genes de RNAr , Metarhizium/química , Metarhizium/genética , Microscopia , Fator 1 de Elongação de Peptídeos/genética , Filogenia , RNA Polimerase II/genética , RNA Fúngico/genética , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Fungi are where one finds them, and if one seeks fungal pathogens affecting flies, then a garbage dump may be an ideal place to find both persistent, abundant fly populations and their fungal pathogens. An obvious fungal epizootic affecting the oriental latrine fly, Chrysomya megacephala (Diptera: Calliphoridae), was observed over several days in mid-February 2015 at the local garbage dump adjacent to the city of Cavalcante, northern Goiás. This site harbored large populations of both C. megacephala and a Musca sp. (Diptera: Muscidae) but only the population of oriental latrine fly was affected by any fungal pathogen and presented unusually dense populations of fresh cadavers. The fungus was identifiable as Pandora bullata (Entomophthorales: Entomophthoraceae) only after a very small number of characteristically decorated resting spores were found in these flies two months later; this represents the first Brazilian (and South American) record of this species. P. bullata is known previously from a small number of North American, European and Australian collections, all of which have included relatively abundant production of resting spores. We cannot dismiss the possibility that the extremely sparse formation of resting spores at this Brazilian site may be due to abiotic factors such as latitude (13°46'40.53â³S), day length, ambient temperatures, or even the precipitation patterns in this mid-tropical montaine site. Epizootic events affecting calliphorids in Brazil strengthen the interest in entomophthoran pathogens for biological control of flies.
Assuntos
Dípteros/microbiologia , Entomophthorales/fisiologia , Animais , Brasil , Muscidae/microbiologia , Controle Biológico de VetoresRESUMO
Numerous isolates of an oomycete 'fungus', Leptolegnia chapmanii, are reported from Brazil for the first time. This aquatic pathogen was baited with Aedes aegypti sentinel larvae from stagnant, temporary bodies of water in selected locations under secondary tropical forest in and near the central Brazilian city of Goiânia and from more distant sites in the western and northern regions of the state of Goiás. Isolates were identified based on their morphological and developmental characters, comparative sequence data for the ITS and TEF loci, as well as their rapid activity against A. aegypti larvae. Taxonomic issues affecting the application of the name L. chapmanii and its typification are rectified. This study contributes to a better understanding of the presence and distribution of this oomycete in Brazil, its sequence-based identification, and of its potential as a biological agent against mosquito vectors.