Molecular taxonomic characterization and infra-specific diversity of entomopathogenic Beauveria bassiana fungi from Argentina.

It has been the aim of this study to molecular-taxonomically identify 15 Beauveria isolates collected from different geographical regions and insect hosts in Argentina and to investigate the levels of inter- and intra-specific diversity across this set of isolates. Based on phylogenetic analyses of EF1A-RPB1-RPB2 concatenated genes and BLOC markers, all Beauveria strains were identify as Beauveria bassiana. Within the B. bassiana clades of both phylogenies, isolates from Argentina were not clustered according to geographic origin or host. The 15 fungal isolates were further analyzed by PCR amplification of the intron insertion hot spot region of the nuclear 28S rRNA encoding sequence. By intron sequence and position, seven different group-I intron combinations termed variants A, B1, B2, C, D, E and F were found in the 15 isolates under study. Variants B1/B2 consisting of a single 28Si2 intron were found in ten isolates, whereas variant A occurred twice and variants C through F were unique across the set of isolates under study. The determination of the different introns and intron combinations in the 28S rRNA gene is a powerful tool for achieving infraspecific differentiation of B. bassiana isolates from Argentina.

Species Discrimination within the Metarhizium PARB Clade: Ribosomal Intergenic Spacer (rIGS)-Based Diagnostic PCR and Single Marker Taxonomy.

(1) Background: The entomopathogenic fungus Metarhizium anisopliae sensu lato forms a species complex, comprising a tight cluster made up of four species, namely M. anisopliae sensu stricto, M. pinghaense, M. robertsii and M. brunneum. Unambiguous species delineation within this "PARB clade" that enables both the taxonomic assignment of new isolates and the identification of potentially new species is highly solicited. (2) Methods: Species-discriminating primer pairs targeting the ribosomal intergenic spacer (rIGS) sequence were designed and a diagnostic PCR protocol established. A partial rIGS sequence, referred to as rIGS-ID800, was introduced as a molecular taxonomic marker for PARB species delineation. (3) Results: PARB species from a validation strain set not implied in primer design were clearly discriminated using the diagnostic PCR protocol developed. Using rIGS-ID800 as a single sequence taxonomic marker gave rise to a higher resolution and statistically better supported delineation of PARB clade species. (4) Conclusions: Reliable species discrimination within the Metarhizium PARB clade is possible through both sequencing-independent diagnostic PCR and sequencing-dependent single marker comparison, both based on the rIGS marker.

Compatibility between Leptolegnia chapmanii and diflubenzuron and neem oil for the control of Aedes aegypti / Compatibilidad de Leptolegnia chapmanii con diflubenzurón y aceite de neem parael control de Aedes aegypti

Abstract Leptolegnia chapmanii is pathogenic to mosquito larvae. The compatibility betweenL. chapmanii and two insect growth regulators (IGR), diflubenzuron and neem oil, was evaluated. L. chapmanii was grown on culture media containing different concentrations of eachIGR. The mycelial growth was significantly reduced with the highest concentrations of IGR(F6,98= 268, p < 0.05). However, the production of zoospores (F6,56= 0.93, p > 0.05) and the lar-val mortality of Aedes aegypti (F6,56= 0.95, p > 0.05) were not significantly different amongtreatments. Furthermore, the percentage of adult emergence in the presence of different con-centrations of diflubenzuron or a neem formulation was determined, and the pathogenic activityof zoospores was evaluated at the concentrations that inhibit the emergence at 30, 50 and 90%.The pathogenicity of zoospores was not significantly different among treatments (F6,14= 0.54,p > 0.05), and the larval mortalities were above 90% in all cases.

Resumen Leptolegnia chapmanii es un patógeno de larvas de mosquitos. Se evaluó la com-patibilidad entre L. chapmanii y dos reguladores del crecimiento de insectos (IGR, por sus siglasen inglés), diflubenzurón y aceite de neem. L. chapmanii creció en medios de cultivo con diferentes concentraciones de estos IGR. El crecimiento micelial fue menor con las concentraciones más altas (F6,98= 268; p < 0,05). No hubo diferencias significativas en la producción de zoosporas (F6,56= 0,93; p > 0,05) ni en la mortalidad de las larvas de Aedes aegypti (F6,56= 0,95; p > 0,05).Se determinó el porcentaje de emergencia de adultos en presencia de diferentes concentra-ciones de diflubenzurón o de un formulado a base del aceite de neem. También se evaluó lapatogenicidad de las zoosporas a las concentraciones de los IGR que inhibieron la emergenciadel 30, 50 y 90% de adultos. No hubo diferencias significativas en la actividad de las zoosporasal comparar los tratamientos (F6,14= 054; p > 0,05). La mortalidad de las larvas fue superior al90%.

A new species of Herpomyces (Laboulbeniomycetes: Herpomycetales) on Periplaneta fuliginosa (Blattodea: Blattidae) from Argentina.

We are becoming increasingly aware of the dazzling diversity of fungi-new taxa are being discovered from poorly sampled habitats and integrative approaches point at (near-)cryptic species in many groups. The class Laboulbeniomycetes, which is composed of three orders (Herpomycetales, Laboulbeniales, Pyxidiophorales), is no exception. However, still, in the orders Herpomycetales and Laboulbeniales, species are predominantly described based on morphology alone. Here, we present a new species of Herpomyces from Argentina parasitic on Periplaneta fuliginosa, the smokybrown cockroach. Herpomyces spegazzinii, sp. nov., is characterized based on morphology and molecular data. Phylogenetic inference based on internal transcribed spacer (ITS, consisting of ITS1-5.8S-ITS2) barcode region supports the status of this fungus as a separate species, sister to the recently described H. shelfordellae.

Adulticidal Activity of Metarhizium anisopliae s.l. (Hypocreales: Clavicipitaceae) Native Strains From Argentina Against Aedes aegypti (Diptera: Culicidae).

The adulticidal activity of six fungal strains of Metarhizium anisopliae (Metschn.) Sorokin s.l. (Hypocreales: Clavicipitaceae) against Aedes aegypti (L.) (Diptera: Culicidae) was assessed. These strains (CEP 085, CEP 087, CEP 120, CEP 350, CEP 404, and CEP 423) were isolated from soil samples or nondipteran hosts collected from areas in Argentina where Ae. aegypti is distributed. Bioassays were performed with four conidial concentrations plus a control of each fungal strain to determine the lethal concentrations (LC50/LC90), the median survival times (ST50), the mean percentage of the surviving individuals, and the mean percentage of mycotized cadavers. The strains were able to infect and kill adult Ae. aegypti. Significant differences were found among the LC50 values, with CEP 423 as the most virulent strain with the lowest LC50 (2.4 × 106 conidia/ml). At 1 × 107 conidia/ml: no significant differences were found in the Kaplan-Meier survival functions among the strains; the ST50 ranged from 5 (CEP 085) to 8 d (CEP 350); and the mean percentage of the surviving adults was between 13.3 (CEP 085, CEP 350 and CEP 423) and 46.7% (CEP 087). Significant differences were also found among strains in the mean percentage of cadavers with fungal sporulation. Strain CEP 423 produced the highest percentage of mycotized adults (70%). The concentration of the inoculum significantly affected the survival of individuals and the percentage of mycotized cadavers within each strain. Metarhizium anisopliae s.l. CEP 423 was selected as the most promising candidate for further research aiming to develop a mycoinsecticide against Ae. aegypti.

Natural occurrence in Argentina of a new fungal pathogen of cockroaches, Metarhizium argentinense sp. nov.

The aim of this study was to search for entomopathogenic fungi that infect wild cockroaches in forest ecosystems in two protected natural areas of Argentina. Two isolates of Metarhizium argentinense were obtained and identified from wild cockroaches (Blaberidae: Epilamprinae) through the use of morphological characteristics and molecular phylogenetic analyses. This novel species was found in Argentina and is a member of the Metarhizium flavoviride species complex. Phylogenetic analyses, based on sequence similarity analysis using internal transcribed spacer (ITS) and a set of four protein-coding marker sequences (EF1A, RPB1, RPB2 and BTUB), supported the status of this fungus as a new species. In addition, we tested the biological activity of the new species through assays against Blattella germanica nymphs and found that the two evaluated isolates were pathogenic. However, isolate CEP424 was more virulent and caused a confirmed mortality of 76 % with a median lethal time of 7.2 d. This study reports the southernmost worldwide location of a Metarhizium species that infects cockroaches and will help expand the knowledge of the biodiversity of pathogenic fungi of Argentine cockroaches.

Impact of short-term temperature challenges on the larvicidal activities of the entomopathogenic watermold Leptolegnia chapmanii against Aedes aegypti, and development on infected dead larvae.

The oomycete Leptolegnia chapmanii is among the most promising entomopathogens for biological control of Aedes aegypti. This mosquito vector breeds in small water collections, where this aquatic watermold pathogen can face short-term scenarios of challenging high or low temperatures during changing ambient conditions, but it is yet not well understood how extreme temperatures might affect the virulence and recycling capacities of this pathogen. We tested the effect of short-term exposure of encysted L. chapmanii zoospores (cysts) on A. aegypti larvae killed after infection by this pathogen to stressful low or high temperatures on virulence and production of cysts and oogonia, respectively. Cysts were exposed to temperature regimes between -12 °C and 40 °C for 4, 6 or 8 h, and then their infectivity was tested against third instar larvae (L3) at 25 °C; in addition, production of cysts and oogonia on L3 killed by infection exposed to the same temperature regimes as well as their larvicidal activity were monitored. Virulence of cysts to larvae and the degree of zoosporogenesis on dead larvae under laboratory conditions were highest at 25 °C but were hampered or even blocked after 4 up to 8 h exposure of cysts or dead larvae at both the highest (35 °C and 40 °C) and the lowest (-12 °C) temperatures followed by subsequent incubation at 25 °C. The virulence of cysts was less affected by accelerated than by slow thawing from the frozen state. The production of oogonia on dead larvae was stimulated by short-term exposure to freezing temperatures (-12 °C and 0 °C) or cool temperatures (5 °C and 10 °C) but was not detected at higher temperatures (25 °C-40 °C). These findings emphasize the susceptibility of L. chapmanii to short-term temperature stresses and underscore its interest as an agent for biocontrol of mosquitoes in the tropics and subtropics, especially A. aegypti, that breed preferentially in small volumes of water that are generally protected from direct sunlight.

Effect of UV-B Irradiation on Water-Suspended Metarhizium anisopliae s.l. (Hypocreales: Clavicipitaceae) Conidia and Their Larvicidal Activity in Aedes aegypti (Diptera: Culicidae).

Ultraviolet (UV) radiation is a key limiting factor for biological pest control with entomopathogenic fungi. While little is known about the impact of UV on Metarhizium anisopliae Metchnikoff (Sorokin) (Hypocreales: Clavicipitaceae) conidia in aquatic mosquito-breeding sites, this study determined the effect of UV-B on the viability and virulence of M. anisopliae sensu lato (s.l.) strain IP 46 in the laboratory against Aedes aegypti (L.) (Diptera: Culicidae) larvae. Conidia were treated in cups under defined water depths (0, 1, 2, and 3 cm) to six different UV-B doses (0, 0.657, 1.971, 3.942, 7.884, 11.826, or 15.768 kJ m-2) at 27 ± 2°C. The ability of treated conidia to germinate up to 24 h postexposure on PDAY + benomyl + chloramphenicol medium at 25 ± 1°C was adversely affected by higher doses of UV-B radiation regardless of the water depth. Germination, however, did not fall below 70% regardless of the test conditions. In fact, conidial virulence against second-instar larvae was not affected by either the water depth (F3,84 = 0.3, P = 0.85) or any tested levels of UV-B radiation (F6,21 ≤ 1.2, P ≥ 0.39) including those distinctly higher than might be expected for tropical sites. These findings strengthen previous observations that IP 46 has significant potential for use against A. aegypti larvae, even when exposed to elevated UV-B irradiance levels in the small breeding sites that are common for this important vector.

Organización y conservación de la colección de hongos patógenos y simbiontes de insectos y otros artrópodos del CEPAVE (CONICET-UNLP), La Plata, Argentina / Organization and preservation of the collection of pathogenic and fungal symbionts of insects and other arthropods from CEPAVE (CONICET-UNLP), La Plata, Argentina

La colección de hongos patógenos y simbiontes de insectos y otros artrópodos del Centro de Estudios Parasitológicos y de Vectores es única por sus características específicas en la Argentina y por preservar hongos en cultivo, in vitro e in vivo. Esta colección está abierta para actividades de investigación, docencia, servicios y asesoramiento público y privado. Un total de 421 aislamientos pertenecientes a 23 géneros (Ascomycota: 16, Entomophthoromycotina: 4 Glomeromycota: 2 y Oomycota: 1) son preservados en la colección mediante diversos métodos: criopreservación en freezer a −20 °C y −70 °C, agua destilada estéril, papel, arena y liofilización. Las cepas que integran la colección fueron aisladas de insectos y de otros artrópodos; y a partir de suelo (usando insectos trampa o aislamiento directo en medios selectivos). La identificación se realizó mediante estudios de caracterización morfológicos y, en algunos casos, por taxonomía molecular. Esta colección se utiliza como centro de referencia para identificación de especies, certificaciones, estudios de investigación y docencia, transferencia tecnológica, servicios a terceros, depósito de cepas y preservación de la diversidad y conservación del germoplasma. Las cepas preservadas son, en su mayor parte, nativas de distintas regiones de la Argentina. La colección fue originada en el año 1988 y está registrada en la base de la Federación Latinoamericana de Colecciones de Cultivos y en la World Federation of Culture Collections.

The collection of fungal pathogens and symbionts of insects and other arthropods of the Centro de Estudios Parasitológicos y de Vectores, La Plata, Argentina, is unique because it preserves in vivo and in vitro cultures of fungal pathogens. This culture collection is open for research, teaching, consulting services, and strain deposit. It contains 421 strains belonging to 23 genera (16 Ascomycota, 4 Entomophthoromycotina, 2 Glomeromycota and 1 Oomycota), and the cultures are preserved by different methods such as cryopreservation in freezer at −20 °C and −70 °C, paper, distilled water and lyophilization. Fungi were isolated from insects, other arthropods, and soil (by using insect baits and selective media). Species were identified by morphological features and in a few strains by molecular taxonomy (PCR of rDNA). This collection is a reference center for species identification/certifications, research and teaching purposes, strain deposit, transference and consultancy services, and its overall goal is to preserve the fungal germplasm and ex situ diversity. Most of the strains are native of Argentina. The collection was originated in 1988 and is registered in the Latin American Federation for Culture Collections and in the World Federation of Culture Collections.

Contribution to the knowledge of pathogenic fungi of spiders in Argentina: Southernmost record in the world / Aporte al conocimiento de los hongos patógenos de arañas en Argentina: El registro más austral del mundo

The aim of this study was to identify entomopathogenic fungi infecting spiders (Araneae) in a protected area of Buenos Aires province, Argentina. The Araneae species identified was Stenoterommata platensis. The pathogens identified were Lecanicillium aphanocladii Zare & W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones & Samson and Ophiocordyceps caloceroides (Berk & M.A. Curtis). This study constitutes the southernmost records in the world and contributes to expanding the knowledge of the biodiversity of pathogenic fungi of spiders in Argentina.

El objetivo de este estudio fue identificar hongos entomopatógenos de arañas en un área protegida de la provincia de Buenos Aires, Argentina. La especie de araña identificada fue Stenoterommata platensis. Los patógenos identificados fueron Lecanicillium aphanocladii Zare y W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones y Samson y Ophiocordyceps caloceroides (Berk y M.A. Curtis). Este estudio constituye el registro más austral del mundo y contribuye a ampliar el conocimiento de la biodiversidad de hongos patógenos de arañas en Argentina.

Contribution to the knowledge of pathogenic fungi of spiders in Argentina. Southernmost record in the world.

The aim of this study was to identify entomopathogenic fungi infecting spiders (Araneae) in a protected area of Buenos Aires province, Argentina. The Araneae species identified was Stenoterommata platensis. The pathogens identified were Lecanicillium aphanocladii Zare & W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones & Samson and Ophiocordyceps caloceroides (Berk & M.A. Curtis). This study constitutes the southernmost records in the world and contributes to expanding the knowledge of the biodiversity of pathogenic fungi of spiders in Argentina.

[Organization and preservation of the collection of pathogenic and fungal symbionts of insects and other arthropods from CEPAVE (CONICET-UNLP), La Plata, Argentina]. / Organización y conservación de la colección de hongos patógenos y simbiontes de insectos y otros artrópodos del CEPAVE (CONICET-UNLP), La Plata, Argentina.

The collection of fungal pathogens and symbionts of insects and other arthropods of the Centro de Estudios Parasitológicos y de Vectores, La Plata, Argentina, is unique because it preserves in vivo and in vitro cultures of fungal pathogens. This culture collection is open for research, teaching, consulting services, and strain deposit. It contains 421 strains belonging to 23 genera (16 Ascomycota, 4 Entomophthoromycotina, 2 Glomeromycota and 1 Oomycota), and the cultures are preserved by different methods such as cryopreservation in freezer at -20°C and -70°C, paper, distilled water and lyophilization. Fungi were isolated from insects, other arthropods, and soil (by using insect baits and selective media). Species were identified by morphological features and in a few strains by molecular taxonomy (PCR of rDNA). This collection is a reference center for species identification/certifications, research and teaching purposes, strain deposit, transference and consultancy services, and its overall goal is to preserve the fungal germplasm and ex situ diversity. Most of the strains are native of Argentina. The collection was originated in 1988 and is registered in the Latin American Federation for Culture Collections and in the World Federation of Culture Collections.

Prevalence of entomophthoralean fungi (Entomophthoromycota) of aphids in relation to developmental stages.

BACKGROUND: Transmission of fungal pathogens of aphids may be affected by the host developmental stage. Brassica and Lactuca sativa L. crops were sampled in Santa Fe, Argentina, to determine the prevalence of fungal-diseased aphids and investigate the differences between developmental stages of aphids. RESULTS: The fungal pathogens identified were Zoophthora radicans (Bref.) A. Batko, Pandora neoaphidis (Remaud. & Hennebert) Humber and Entomophthora planchoniana Cornu. Their prevalence on each crop was calculated. The numbers of infected aphids were significantly different between the different developmental stages on all crops except B. oleracea var. botrytis L. CONCLUSIONS: The entomophthoralean fungi identified are important mortality factors of aphids on horticultural crops in Santa Fe. The numbers of infected nymphs and adults were significantly different, nymphs being the most affected developmental stage. © 2015 Society of Chemical Industry.

Cuticle Fatty Acid Composition and Differential Susceptibility of Three Species of Cockroaches to the Entomopathogenic Fungi Metarhizium anisopliae (Ascomycota, Hypocreales).

Differences in free fatty acids (FFAs) chemical composition of insects may be responsible for susceptibility or resistance to fungal infection. Determination of FFAs found in cuticular lipids can effectively contribute to the knowledge concerning insect defense mechanisms. In this study, we have evaluated the susceptibility of three species of cockroaches to the entomopathogenic fungi Metarhizium anisopliae (Metschnikoff) Sorokin by topical application. Mortality due to M. anisopliae was highly significant on adults and nymphs of Blattella germanica L. (Blattodea: Blattellidae). However, mortality was faster in adults than in nymphs. Adults of Blatta orientalis L. (Blattodea: Blattidae) were not susceptible to the fungus, and nymphs of Blaptica dubia Serville (Blattodea: Blaberidae) were more susceptible to the fungus than adults. The composition of cuticular FFAs in the three species of cockroaches was also studied. The analysis indicated that all of the fatty acids were mostly straight-chain, long-chain, saturated or unsaturated. Cuticular lipids of three species of cockroaches contained 19 FFAs, ranging from C14:0 to C24:0. The predominant fatty acids found in the three studied species of cockroaches were oleic, linoleic, palmitic, and stearic acid. Only in adults of Bl. orientalis, myristoleic acid, γ-linolenic acid, arachidic acid, dihomolinoleic acid, and behenic acid were identified. Lignoceric acid was detected only in nymphs of Bl. orientalis. Heneicosylic acid and docosahexaenoic acid were identified in adults of Ba. dubia.

Effect of ultraviolet-A radiation on the production of Leptolegnia chapmanii (Saprolegniales: Saprolegniaceae) zoospores on dead Aedes aegypti (Diptera: Culicidae) larvae and their larvicidal activity.

Impact of UV-radiation in entomopathogens in aquatic environments remains little investigated. The present study reports on the effect of UV-A on the larvicidal activity of Leptolegnia chapmanii zoospores in Aedes aegypti; on the production of zoospores in larvae killed by the pathogen and then exposed to UV-A; and on the activity of these zoospores against healthy larvae. Whereas the virulence of free zoospores in A. aegypti larvae was affected by a UV-A exposure time longer than 10min, production of zoospores in larvae and their virulence were not hampered at a maximal 8h exposure of dead larvae to UV-A. Findings suggest that dead larvae and zoosporangia provide a certain protection to zoospores against UV-A and emphasize the susceptibility of free encysted zoospores to such radiation.

[Natural ocurrence of entomopathogenic fungi in soils cultivated with Paraguay tea (Ilex paraguariensis St. Hil.) in Misiones, Argentina]. / Ocurrencia natural de hongos entomopatógenos en suelos cultivados con yerba mate (Ilex paraguariensis St. Hil.) en Misiones, Argentina.

This study aimed to morphologically isolate, identify and characterize entomopathogenic fungi present in soils cultivated with Paraguay tea (Ilex paraguariensis). A survey of native entomopathogenic fungi was conducted from 40 soil samples grown with Paraguay tea in the province of Misiones, Argentina, from May 2008 to June 2010. The soil dilution plate methodology on selective culture media was used to isolate microorganisms. Taxonomic identification was performed using macroscopic and microscopic characters and specific keys. Twenty nine strains, belonging to the species Beauveria bassiana (n = 17), Metarhizium anisopliae (n = 2) and Purpureocillium lilacinum (n = 10) were isolated and identified.

Ocurrencia natural de hongos entomopatógenos en suelos cultivados con yerba mate (Ilex paraguariensis St. Hil.) en Misiones, Argentina / Natural ocurrence of entomopathogenic fungi in soils cultivated with Paraguay tea (Ilex paraguariensis St. Hil.) in Misiones, Argentina

Este trabajo tuvo por objetivo aislar, identificar y caracterizar morfológicamente hongos entomopatógenos presentes en suelos cultivados con yerba mate (Ilex paraguariensis St. Hil.). Se realizó una prospección de hongos entomopatógenos nativos a partir de 40 muestras de suelos cultivados con yerba mate ubicados en la provincia de Misiones, República Argentina, desde mayo de 2008 hasta junio de 2010. Las muestras de suelo se obtuvieron en cercanías de plantas de yerba mate, se aplicó la técnica de dilución seriada en medios de cultivos selectivos. Después de obtenidos los cultivos puros, los hongos fueron caracterizados macroscópica y microscópicamente, y se los identificó mediante el uso de claves taxonómicas específicas. Se aislaron 29 cepas fúngicas pertenecientes a las especies Beauveria bassiana (n = 17), Metarhizium anisopliae (n = 2) y Purpureocillium lilacinum (n = 10)

This study aimed to morphologically isolate, identify and characterize entomopathogenic fungi present in soils cultivated with Paraguay tea (Ilex paraguariensis). A survey of native entomopathogenic fungi was conducted from 40 soil samples grown with Paraguay tea in the province of Misiones, Argentina, from May 2008 to June 2010. The soil dilution plate methodology on selective culture media was used to isolate microorganisms. Taxonomic identification was performed using macroscopic and microscopic characters and specific keys. Twenty nine strains, belonging to the species Beauveria bassiana (n = 17), Metarhizium anisopliae (n = 2) and Purpureocillium lilacinum (n = 10) were isolated and identified

Ocurrencia natural de hongos entomophthorales de áfidos plaga de Medicago sativa L. en Argentina / Natural occurrence of entomophthoroid fungi of aphid pests on Medicago sativa L. in Argentina

Se encontraron cuatro especies de hongos Entomophthorales, Pandora neoaphidis, Zoophthora radicans, Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) y Neozygites fresenii (Neozygitales: Neozygitaceae) infectando a Aphis craccivora, Therioaphis trifolii, Acyrthosiphon pisum y a especies no identificadas pertenecientes al género Acyrthosiphon en cultivos de alfalfa (Medicago sativa L.), en la Argentina. Los muestreos fueron realizados en cinco sitios (Ceres, Rafaela, Sarmiento, Monte Vera y Bernardo de Irigoyen) de la provincia de Santa Fe. Zoophthora radicans fue el patógeno más importante registrado principalmente en Acyrthosiphon sp. Zoophthora radicans fue exitosamente aislado y mantenido en cultivos puros. Este estudio documenta por primera vez en la Argentina la presencia de hongos Entomophthorales infectando áfidos en alfalfa

Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Zoophthora radicans (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae) were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen) in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L.) aphids in Argentina

Characterization and phylogeny of Isaria spp. strains (Ascomycota: Hypocreales) using ITS1-5.8S-ITS2 and elongation factor 1-alpha sequences.

The elongation factor 1-alpha (EF1-α) and the internal transcribed spacer (ITS) regions ITS1 and ITS2 (ITS1-5.8S-ITS2) sequences were used to characterize and to identify Isaria isolates from Argentina, Mexico, and Brazil, as well as to study the phylogenetic relationships among these isolates and other related fungi from the order Hypocreales. The molecular characterization, which was performed by PCR-RFLP of EF1-α and ITS1-5.8-ITS2 genes, was useful for resolving representative isolates of Isaria fumosorosea, Isaria farinosa, and Isaria tenuipes and to confirm the taxonomic identity of fungi from Argentina, Mexico, and Brazil. The phylogenetic analyses showed three clades corresponding to three families of Hypocreales. The genus Isaria was confirmed as polyphyletic and in family Cordycipitaceae, Isaria species were related to anamorphic species of Beauveria, Lecanicillium, and Simplicillium and to teleomorphic Cordyceps and Torrubiella. Therefore, EF1-α and ITS1-5.8S-ITS2 genes were found to be powerful tools for improving the characterization, identification, and phylogenetic relationship of the Isaria species and other entomopathogenic fungi.

A simple method for the detection of Leptolegnia chapmanii from infected Aedes aegypti larvae.

Significant progress in developing Leptolegnia chapmanii as a biological control agent against mosquitoes will be accelerated by improved and simpler methods to detect and to isolate this virulent and rapidly lethal watermold from field-collected mosquito larvae. To date, however, this oomycete has remained understudied and little used. This study presents a simplified method to detect Leptolegnia in infected Aedes aegypti larvae. The development of L. chapmanii inside mosquitoes is easily monitored when pathogen-treated larvae are quasi-immobilized for an initial 48 h in the water film on plates of water agar amended with antibiotic (chloramphenicol, 0.5-1 g/L) and fungicide (thiabendazole, 4-8 g/L) and then transferred to a larger volume of water for an additional 48 h. Surprisingly, chloramphenicol stimulated oosporogenesis by L. chapmanii. The method permits processing of large numbers of A. aegypti and other culicid larvae and is useful for both obtaining new strains and also monitoring the efficacy of L. chapmanii during field tests.