Effect of plant caging and insecticide application on leaf beetle (Phyllotreta sp.) abundance and induced damage on mustard plants (Brassica rapa var. parachinensis L.)

Effect of plant caging and insecticide application on leaf beetle (Phyllotreta sp.) abundance and induced damage on mustard plants (Brassica rapa var. parachinensis L.) This study was aimed to test the efficacy of plant caging and insecticide treatment on the leaf beetle abundance and the leaf beetle-induced damage on mustard plants. The field experiment consisted of three treatments (caging, insecticide and control) that were set in a completely randomized design with six replicates. Bamboo-framed screen cloth was used as cage while alfametrin was applied at recommended rate. The response variables were leaf beetle abundance (observed using a direct count method) and damage on mustard plants (percentage of severity and incidence). Result showed that plant caging effectively reduced pest abundance, damage severity (43%) and damage incidence (83%). Alfametrin spray slightly reduced leaf beetle abundance, damage severity (12%) and damage incidence (5%). Leaf beetle abundance positively correlated with damage severity (R2 = 0.714). Addition of one leaf beetle individual increased damage severity of 5%.