Effect of nitrogen fertilization on giant-missionary-grass on the spittlebugs population dynamics

Abstract

Spittlebug insects (Hemiptera: Cercopidae) reduce the yield and pastures quality. To study the effect of nitrogen fertilization on giant-grass-missionary (Axonopus catharinensis Valls) on population dynamics of these pests an experiment was carried in Epagri/Cepaf in Chapecó, Santa Catarina State, Brazil, from October 2008 to September 2011. The experimental design was a randomized block with seven treatments and five replications. The treatments were applications of pig manure (DLS) equivalent the doses of 100, 200, 300, 400 and 500 kg of N.ha-1 and two mineral fertilization with P2 O5 + K2 O (control) and N + P2 O5 + K2 O (standard) following the soil analysis recommendation. The evaluations were carried in the pasture two times a month counting nymph “foams” and spittlebug adults captured with entomological net. Fertilization of the giant-missionarygrass increases the spittlebugs population. Fertilization with annual doses ≥ 100kg of N.ha-1 favors the development of these insects.