Population development of rice black bug, Scotinophara latiuscula (Breddin), under varying nitrogen in a field experiment
Horgan, F.G.; Vu, Q.; Bernal, C.C.; Ramal, A.F.; Villegas, J.M.; Almazan, M.L.P.
Abstract The effects of nitrogenous fertilizers on black bug (Hemiptera: Pentatomidae) colonization and population development in rice fields has not been studied previously. This study reports on the distribution of adults, eggs and nymphs of the black bug, Scotinophara latiuscula (Breddin) during a seasonal outbreak in a rice (Oryza sativa L.) yield experiment that varied nitrogen application rates. Plots at the edge of the experimental field had higher black bug densities. Adult distribution was only weakly affected by nitrogen level. Densities of egg-masses and nymphs increased linearly with increasing nitrogen rates. Nymph development was also more advanced under high nitrogen. Oviposition was highest on larger plants with high grain numbers (actively filling grain), but was otherwise unaffected by the varieties in the experiment. Our results indicate that the build-up of black bug populations in rice is influenced by nitrogen fertilizer rates mainly acting on egg-laying and nymph development.