Applying different infective structures of Beauveria bassiana to Coffea arabica infested with Hypothenemus hampei (Coleoptera: Curculionidae) under field

Coffee is the most appreciated beverage in worldwide; Brazil is the largest producer and exporter of this commodity. Organochlorine endosulfan was banned from the country in 2013 due to its teratogenic agent-related features. Since then, coffee plantations have experienced increased Hypothenemus hampei infestation rates. The aim of the current study is to assess variations in the rates of Coffea arabica fruits brocaded by H. hampei after the application of entomopathogenic fungal species Beauveria bassiana IBCB66. Experiments were carried out with 'Catuaí' and 'Mundo Novo' cultivars between 2018 and 2020, during the borer transit period. Three experiments were carried out based on the application of the aforementioned fungal species on the investigated coffee plant species, both by spraying and sprinkling, at 30-day intervals; 10 fruits were collected per face of each useful plant in each repetition. The experiment has followed a randomized blocks design with five treatments, including the control, and five repetitions, each. Beauveria bassiana Ecobass (IBCB66) wettable powder spray, at the concentration of 2 × 1013·ha­1, was used in experiments I and II. On the other hand, the mix used in experiment III was prepared with blastospores at concentration of 5 × 1012·ha­1 blastospores + 0.1% Silwet. The sprinkling process in all three experiments has used dry aerial conidia at concentration of 2 × 1013·ha­1. Collected data were subjected to analysis of variance (ANOVA), which was followed by Fisher's test at 5% probability level, in the SISVAR software. More than 35,000 fruits were assessed. In addition to variations between experiments, results have evidenced that the rate of brocaded fruits remained high.

Entomopathogenic fungi associated with citrus blackfly (Aleurocanthus woglumi Ashby) in Southern Bahia / Fungos entomopatogênicos associados à mosca-negra-dos-citros (Aleurocanthus woglumi Ashby) na região Sul da Bahia

The Brazilian citrus industry is the world leading producer of concentrated orange juice. The presence of citrus blackfly Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) in Brazilian citrus orchards has led to agribusiness problems due to damages and inadequate control measures. Entomopathogenic fungi act as natural control in high precipitation regions, being important components of integrated management. The objective of this work was to identify entomopathogenic fungi associated with citrus blackfly in the southern region of the state of Bahia. Orange (Citrus sinensis L. Osbeck) and Tahiti lime (Citrus latifolia Tann.) leaves infested with citrus blackfly eggs, nymphs and pupae were collected in orchards in the municipalities of Ilhéus and Laje, Bahia, Brazil. Fragments of fungi colonies were disinfected with 70% alcohol and 2% sodium hypochlorite, and then washed with distilled water. After drying, the material was placed in Petri dishes with PDA and chloramphenicol, which were placed in bio-oxygen demand (BOD) incubators (27 ± 2 ºC, 12-hour photophase) until spore production. After isolation, the fungi were replaced in PDA Petri dishes and kept under continuous fluorescent light for 30 days to stimulate growth and spore production. The fungi isolates were preserved in test tubes containing PDA and mineral oil, and then stored at 18 ºC in a refrigerated incubator. Entomopathogenic fungi Aschersonia cf. aleyrodis Webber and Aegerita webberi Fawcett were associated with citrus blackfly in Southern Bahia.(AU)

A citricultura brasileira lidera mundialmente a produção de suco concentrado de laranja. A presença da mosca-negra-dos-citros Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) em pomares citrícolas brasileiros tem gerado problemas ao agronegócio, devido aos danos e medidas inadequadas de controle. O controle natural por ação de fungos entomopatogênicos é comum em regiões com alta precipitação, sendo esses agentes importantes componentes do manejo integrado. O objetivo deste trabalho foi identificar fungos entomopatogênicos associados à mosca-negra-dos-citros na região Sul do estado da Bahia. Foram coletadas folhas de laranjeira (Citrus sinensis L. Osbeck) e de lima-Tahiti (Citrus latifolia Tann.) infestadas com ovos, ninfas e pupários da mosca-negra-dos-citros em pomares nos municípios de Ilhéus e Laje, Bahia. Fragmentos de colônias dos fungos foram desinfetados com álcool 70% e hipoclorito de sódio a 2% e, posteriormente, com água destilada. Após secagem, o material foi colocado em placas de Petri com BDA e cloranfenicol, em seguida alocadas em câmaras climatizadas do tipo BOD (27 ± 2 ºC, 12 horas de fotofase) até a produção de esporos. Após o isolamento, os fungos foram recolocados em placas de Petri com BDA, as quais ficaram sob luz fluorescente contínua durante 30 dias para estimular o crescimento e a produção de esporos. Isolados dos fungos obtidos foram preservados em tubos de ensaio contendo BDA e óleo mineral, e armazenados a 18 ºC em câmara climatizada. Os fungos entomopatogênicos associados à mosca-negra-dos-citros na região Sul da Bahia foram Aschersonia cf. aleyrodis Webber e Aegerita webberi Fawcett.(AU)

Liquid production of entomopathogenic fungi and ultraviolet radiation and temperature effects on produced propagules / Produção líquida de fungos entomopatogênicos e efeitos da radiação ultravioleta e da temperatura sobre os propágulos produzidos

The purpose of this paper was to evaluate the liquid culture media for the production of Metarhizium anisopliae (IBCB 425) and Beauveria bassiana (IBCB 66), as well as the tolerance of these seedlings to the ultraviolet action and to the temperature. Twelve treatments composed of combinations between carbon and nitrogen concentrations were assessed. In order to determine the effect of ultraviolet radiation, plates with blastos-pores were exposed to it for 25 and 50 seconds. To determine the temperature efect, blastospores from culture media were exposed to 20, 25, 30 and 35°. For the virulence experiments, caterpillars of Diatraea saccharalis were sprayed with 2 mL of fungal suspension with the aid of a Potter tower. Te best media for M. anisopliae are 16.00 g (carbon) + 7.00 g (nitrogen) and 14.40 g (carbon) + 7.00 g (nitrogen), whereas for B. bassiana: 20.00 g (carbon) + 6.30 g (nitrogen) and 20.00 g (carbon) + 7.00 g (nitrogen). Te longer the exposure to ultraviolet radiation, the smaller the number of colonies. At 35°, there is a significant decrease in the formation of colonies. Te produced seedlings of fungi are pathogenic to D. saccharalis.(AU)

O objetivo deste trabalho foi avaliar os meios de cultura líquidos para a produção de Metarhizium anisopliae (IBCB 425) e Beauveria bassiana (IBCB 66), bem como a tolerância desses propágulos à ação dos raios ultravioleta e à temperatura. Foram avaliados 12 tratamentos compostos pelas combinações entre carbono e nitrogênio. Para determinar o efeito da radiação ultravioleta, placas com blastósporos foram expostas à radiação por 25 e 50 segundos. Para conhecer o efeito da temperatura, os blastósporos de meios de cultura foram expostos a temperaturas de 20, 25, 30 e 35°. Para os experimentos de virulência, as lagartas Diatraea saccharalis foram pulverizadas com 2mL de suspensão fúngica, com o auxílio de uma torre de Potter. Os melhores meios para M. anisopliae são 16,00 g (carbono) + 7,00 g (nitrogênio) e 14,40 g (carbono) + 7,00 g (nitrogênio), e para B. bassiana, 20,00 g (carbono) + 6,30 g (nitrogênio) e 20,00 g (carbono) + 7,00 g (nitrogênio). Quanto mais tempo de exposição à radiação ultravioleta, menor o número de colônias. Aos 35°, há uma diminuição signifcativa na formação de colônias. Os propágulos produzidos pelos fungos são patogênicos a D. saccharalis.(AU)