RESUMEN
The Thaumastocoris peregrinus spread to eucalyptus plantations in many countries. Chemical control is a questionable measure, mainly due to the environmental impact, high cost and moreover has the use restricted by the forest certifications. Bio-insecticides may have similar efficiency to chemical products to control T. peregrinus. The chemical thiamethoxam, thiamethoxam + lambda-cyhalothrin, acephate and the microbial Beauveria bassiana and Metarhizium anisopliae insecticides were tested at different doses to manage T. peregrinus. The products were sprayed on eucalyptus plants using aircraft and populations of this insect were counted before application and at 1, 14 and 21 days afterwards (DAA). Ten eucalyptus trees were evaluated per plot, with the collection of ten leaves from the middle third of the crown of each tree, and the number of T. peregrinus nymphs and adults obtained per leaf was determined. All the chemical insecticides had similar control at 1 DAA for T. peregrinus nymphs and adults. At 14 DAA, the number of T. peregrinus nymphs and adults on eucalyptus leaves was similar for the chemical and microbial insecticide treatments. At 21 DAA the control efficiency of T. peregrinus nymphs and adults was higher than 80% with all insecticides. The entomopathogenic insecticides have potential for aerial application to control T. peregrinus nymphs and adults and provide viable and environmentally-friendly alternative to manage this pest.
Asunto(s)
Eucalyptus/parasitología , Hemípteros/crecimiento & desarrollo , Insecticidas/química , Control Biológico de Vectores/métodos , Animales , Beauveria/fisiología , Hemípteros/efectos de los fármacos , Hemípteros/microbiología , Insecticidas/toxicidad , Metarhizium/fisiología , Nitrilos/química , Ninfa/efectos de los fármacos , Ninfa/microbiología , Hojas de la Planta/parasitología , Piretrinas/química , Tiametoxam/química , Tiametoxam/toxicidadRESUMEN
Hylesia spp. (Saturniidae), important moths for public health due to urticating bristles of their larvae and/or adults, are collected in different habitats with potential to defoliate plants in agriculture and forest systems. Biological and morphological characteristics of Hylesia paulex (Dognin, 1922) (Lepidoptera: Saturniidae) fed with Eucalyptus urophylla (Myrtaceae) were studied in the laboratory. Recently-emerged caterpillars of this species were separated in 10 plastic pots (500ml) with 30 of them per pot, and fed daily with fresh leaves of E. urophylla until they reached adult stage. The egg incubation period of H. paulex was 32.00 ±1.19 days with 65.32 ±14.52% viability, and the duration of the larval stage reached 67.83 ±0.84 days, with seven instars. The gregarious behavior is important to maintain a high survival rate during this stage for H. paulex. The pre-pupa and pupa stages of this insect lasted 3.87 ±0.16 and 21.67 ±0.79 days, respectively. The longevity of females of this species was longer (4.50 ±0.54 days) than that of males (2.80 ±0.44 days). The mean number of eggs per egg mass was 132.3. Moths of H. paulex completed its life cycle, satisfactorily, with leaves of E. urophylla in the laboratory.
Hylesia spp. (Saturnidae), una polilla importante en salud pública debido a las cerdas urticantes de las l arvas y/o de los adultos, son recolectadas en diferentes ambientes con potencial de desfoliación de plantas tanto en agricultura como en sistemas forestales. Características biológicas y morfológicas de Hylesia paulex (Dognin, 1922) (Lepidoptera: Saturniidae) alimentados con Eucalyptus urophylla fueron estudiados en laboratorio. Larvas recién emergidas de esa especie fueron separadas en vasos plásticos (500 ml) con 30 individuos por vaso y alimentados diariamente con hojas frescas de E. urophylla hasta alcanzar el estado adulto. El periodo de incubación de los huevos de H. paulex fue de 32 ±1,19 días con un 65,32 ±14,52% de viabilidad y duración del estado larval de 67,83 ±0,84 días, con siete instares. El comportamiento gregario es importante para mantener una alta tasa de supervivencia durante estos estados en H. paulex. Los estados de pre-pupa y pupa del insecto duraron 3,87 ±0,16 y 21,67 ±0,79 días, respectivamente. La longevidad de las hembras de la especie fue de 4,50 ±0,54 días y para machos de 2,80 ±0,44 días. El número medio de huevos por masa de huevos fue de 132,3. La polilla H. paulex completa su ciclo de vida, satisfactoriamente, con hojas de E. urophylla en laboratorio.
Hylesia spp. (Saturniidae), mariposas importantes para a saúde pública devido às cerdas urticantes de suas larvas e/ou adultos, são coletadas em diferentes hábitats com potencial de desfolhar plantas em sistemas agrícolas e florestais. Parâmetros biológicos e morfológicos de Hylesia paulex (Dognin, 1922) (Lepidoptera: Saturniidae) alimentada com Eucalyptus urophylla (Myrtaceae) foram estudados em laboratório. Lagartas recém-emergidas dessa espécie foram separadas em 10 potes plásticos (500ml) com 30 delas por pote e alimentadas, diariamente, com folhas frescas de E. urophylla até o estágio adulto. O período de incubação dos ovos de H. paulex foi de 32,00 ±1,19 dias com 65,32 ±14,52% de viabilidade e duração do estágio larval de 67,83 ±0,84 dias, com sete estádios. O comportamento gregário é importante para manter a alta taxa de sobrevivência durante esses estádios para H. paulex. Os estágios de pré-pupa e pupa desse inseto duraram 3,87 ±0,16 e 21,67 ±0,79 dias, respectivamente. A longevidade das fêmeas dessa espécie foi maior (4,50 ±0,54 dias) que a dos machos (2,80 ±0,44 dias). O número de ovos/postura foi de 132,3. Mariposas de H. paulex completaram seu ciclo de vida, satisfatoriamente, com folhas de E. urophylla em laboratório.