ABSTRACT
We report the first occurrence of Zoophthora radicans infecting adults of Gyropsylla spegazziniana Lizer & Trelles in a commercial Paraguay tea plantation (Ilex paraguariensis), in Cascavel, PR, Brazil. The fungus prevalence was high (90% of mortality), considered a natural epizooty.
Subject(s)
Entomophthorales/isolation & purification , Hemiptera/microbiology , Animals , BrazilABSTRACT
A primeira ocorrência de Zoophthora radicans (Entomophthorales: Entomophthoraceae) infectando adultos de Gyropsylla spegazziniana Lizer & Trelles (Hemiptera: Psyllidae) em plantio comercial de erva-mate (Ilex paraguariensis), em Cascavel, PR, Brasil, é relatada. A prevalência do fungo foi elevada (90 por cento de mortalidade), sendo considerada uma epizootia natural.
We report the first occurrence of Zoophthora radicans infecting adults of Gyropsylla spegazziniana Lizer & Trelles in a commercial Paraguay tea plantation (Ilex paraguariensis), in Cascavel, PR, Brazil. The fungus prevalence was high (90 percent of mortality), considered a natural epizooty.
Subject(s)
Animals , Entomophthorales/isolation & purification , Hemiptera/microbiology , BrazilABSTRACT
A terra de diatomácea (TD) é uma alternativa potencial para o controle do cascudinho-dosaviários, Alphitobius diaperinus (Panzer). O objetivo do presente estudo foi conhecer a interferência de alguns fatores ambientais e comportamentais dessa espécie sobre a efi ciência da terra diatomácea no seu controle. Para isso, avaliou-se o efeito da temperatura do ambiente e do substrato (ração parafrangos e cama do aviário) na atividade da TD, assim como a atividade repelente do produto sobre adultos. A 32ºC a mortalidade de insetos foi signifi cativamente maior (53 e 84%, respectivamente para as concentrações de 86 e 172 g/m2) (P < 0,05). Além disso, o substrato infl uenciou, obtendo-se mortalidade de 95% na ração, contra apenas 4% na cama de aviário. Parte dos resultados pode ser atribuída à remoção das partículas de TD pela cama de aviário, conforme indicado pela análise em microscopia eletrônica de varredura (MEV) e também pela determinação da concentração de rodamina na superfície dos insetos. Quanto ao comportamento dos insetos, as armadilhas com TD capturaramcerca de 50% menos insetos que aquelas contendo apenas ração, mostrando, assim, a ação repelentedo produto. Assim, os fatores ambientais infl uenciam a efi ciência de TD e, portanto, devem ser levados em consideração para orientar as estratégias de utilização de TD em campo.
Diatomaceous earth (DE) is a potential alternative to control the lesser mealworm of poultry farms Alphitobius diaperinus (Panzer). Our study aimed to understand the role of some of theenvironmental and insect behavioral factors play on DE effectiveness, such as the substrate (chicken food and poultry house litter), temperature and DE repellent activity on lesser mealworm adults. Mortality was higher at the highest temperature (32ºC), and it increased with DE concentration (53and 84% respectively, for concentrations of 86 and 172 g/m2) (P < 0.05). The substrate also infl uencedDE effectiveness: 95% mortality was observed in the feed, against 4% in the poultry litter. Part of these results can be attributed to the removal of DE particles by the poultry bedding, as supported by scanning electron microscopy (SEM) observations and rhodamine concentration on the surface of the insects. As to insect behavior, DE had a repellent effect, since trap capture decreased nearly 50% in traps containing DE as opposed to those containing only food. Therefore, environmental factors do affect the DE effectiveness, and they must be taken into consideration when looking into developing control strategies in the field.
Subject(s)
Animals , Coleoptera , Diatomaceous Earth , Pest Control, Biological , Coleoptera/ultrastructure , Microscopy, Electron, ScanningABSTRACT
Diatomaceous earth (DE) is a potential alternative to control the lesser mealworm of poultry farms Alphitobius diaperinus (Panzer). Our study aimed to understand the role of some of the environmental and insect behavioral factors play on DE effectiveness, such as the substrate (chicken food and poultry house litter), temperature and DE repellent activity on lesser mealworm adults. Mortality was higher at the highest temperature (32 masculineC), and it increased with DE concentration (53 and 84% respectively, for concentrations of 86 and 172 g/m(2)) (P < 0.05). The substrate also influenced DE effectiveness: 95% mortality was observed in the feed, against 4% in the poultry litter. Part of these results can be attributed to the removal of DE particles by the poultry bedding, as supported by scanning electron microscopy (SEM) observations and rhodamine concentration on the surface of the insects. As to insect behavior, DE had a repellent effect, since trap capture decreased nearly 50% in traps containing DE as opposed to those containing only food. Therefore, environmental factors do affect the DE effectiveness, and they must be taken into consideration when looking into developing control strategies in the field.
