Evaluación de insecticidas para el manejo de la chinche del aguacate, monalonion velezangeli carvalho and costa (hemiptera: miridae)

Abstract

La chinche Monalonion velezangeli es un insecto plaga que causa danos a brotes terminales y frutos del aguacate, haciendo que estos ultimos se sequen, se pasmen y sean rechazados en la comercializacion; ademas afecta el desarrollo y crecimiento del arbol. No se han definido estrategias para manejo de la plaga. Los productores utilizan insecticidas que no estan registrados para este insecto. En esta investigacion se evaluaron insecticidas de baja descarga quimica sobre M. velezangeli bajo condiciones controladas. Se utilizo un diseno de Bloques Completos al Azar, con once tratamientos y cuatro repeticiones. Los tratamientos fueron los insecticidas deltametrina, -cihalotrina, imidacloprid, thiametoxam,spinosad, spiromesifen, diflubenzuron, diafentiuron y una mezcla de thiametoxam + -cihalotrina, mas un testigo relativo (aplicacion agua) y un testigo absoluto (sin aplicacion). La unidad experimental consistio de un arbusto de guayaba común con 10 individuos confinados en una jaula de tela tul. Los tratamientos se aplicaron una vez, con los insectos confinados en la jaula. Se identifico que deltametrina, - cihalotrina, thiametoxam, imidacloprid y la mezcla de thiametoxam mas - cihalotrina causan mortalidad entre 85 y 100% sobre M. velezangeli, 24 horas despues de ser aplicados; tres dias despues, la mortalidad alcanza el 100%. Estos productos permiten proteger el vegetal del dano de la plaga al causar mortalidad en un tiempo corto y pueden ser integrados a un programa de manejo integrado de este insecto. El diafentiuron causa mortalidades entre 51-81%. Spinosad, spiromesifen y diflubenzuron fueron ineficientes para el manejo de M. velezangeli. No se evidencio efecto de diafentiuron, diflubenzuron y spiromesifen sobre la progenie de los adultos expuestos. Las ninfas tratadas, que luego alcanzaron el estado adulto, dieron origen a un menor numero de ninfas; sin embargo, este efecto debe dilucidarse mejor./Abstract. The bug (Monalonion velezangeli) generates damage in avocado end buds, affecting the tree development. When the attack is located on the fruit it causes its drying and therefore its rejection. There are no strategies to manage this plague, so producers use insecticides without any evaluation about their effectiveness. In this research, we evaluated insecticides with a novel mode of action on M. velezangeli under controlled conditions. We used a randomized complete block design, with eleven treatments and four replications. The treatment set was composed by deltamethrin, -cyhalothrin, imidacloprid, thiamethoxam, spinosad, spiromesifen, diflubenzuron, diafentiuron and a mixture of thiamethoxam+ - cyhalothrin, plus a control treatment with water and a control treatment with no application. The experimental unit was a common guava shrub with ten insects confined within a tul cage. Treatments were applied once with the insects inside the cage. Deltamethrin, -cyhalothrin, thiamethoxam, imidacloprid and the mixture of thiamethoxam+ -cyhalothrin caused mortalities between 85 and 100% on M. velezangeli 24 hours after being applied; three days after application, mortality is 100%, protecting the plant from the plague. These products can be included in an integrated pest management program for M. velezangeli. Diafenturion caused mortalities between 51 and 81%. No effect of diafenturion, diflubenzuron or spiromesifen was evidenced on exposed adult progeny, but treated nymphs that became adult originated a lesser quantity of nymphs. This effect should be better elucidated

Abstract: The bug (Monalonion velezangeli) generates damage in avocado end buds, affecting the tree development. When the attack is located on the fruit it causes its drying and therefore its rejection. There are no strategies to manage this plague, so producers use insecticides without any evaluation about their effectiveness. In this research, we evaluated insecticides with a novel mode of action on M. velezangeli under controlled conditions. We used a randomized complete block design, with eleven treatments and four replications. The treatment set was composed by deltamethrin, λ-cyhalothrin, imidacloprid, thiamethoxam, spinosad, spiromesifen, diflubenzuron, diafentiuron and a mixture of thiamethoxam+ λcyhalothrin, plus a control treatment with water and a control treatment with no application. The experimental unit was a common guava shrub with ten insects confined within a tul cage. Treatments were applied once with the insects inside the cage. Deltamethrin, λ-cyhalothrin, thiamethoxam, imidacloprid and the mixture of thiamethoxam+ λ-cyhalothrin caused mortalities between 85 and 100% on M. velezangeli 24 hours after being applied; three days after application, mortality is 100%, protecting the plant from the plague. These products can be included in an integrated pest management program for M. velezangeli. Diafenturion caused mortalities between 51 and 81%. No effect of diafenturion, diflubenzuron or spiromesifen was evidenced on exposed adult progeny, but treated nymphs that became adult originated a lesser quantity of nymphs. This effect should be better elucidated.