Tolerance to nymphs and adults of Mahanarva spectabilis (Hemiptera: Cercopidae) by forage plants in fertilized soils.

BACKGROUND: Several factors may degrade pastures, in particular, inadequate nutrient application and spittlebug attacks. Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae), one of the species that occur in Brazil, is a limiting pest in forage production. The current investigation analyzes the influence of fertilization with the macronutrients nitrogen, phosphorus and potassium (NPK) on the survival of nymphs of M. spectabilis and damage by nymphs and adults on the production, quality and regrowth capacity of the forages Brachiaria ruziziensis, Pennisetum purpureum and Digitaria sp.

RESULTS: Fertilization of the forages differentially affected damage by spittlebug herbivory. Attacks by nymphs and adults decreased chlorophyll content, regrowth of plants and forage quality and increased injury, regardless of fertilization. The availability of nutrients in the soil did not merely decrease fiber content but also increased crude protein, chlorophyll content and regrowth, even when pest-infested. Soil fertilization increased the capacity of forage plants to lessen, albeit not eliminate, injury effects by M. spectabilis.

CONCLUSION: Forages in fertilized soil are more tolerant to attacks by M. spectabilis nymphs and adults. This article is protected by copyright. All rights reserved.