Abstract
A detailed study was made on different components of integrated management of brown planthopper (BPH), Nilaparvata lugens (Stål.) (Homoptera : Delphacidae), a major pest of rice in Bangladesh. Four experiments consisting the effect of cultural practices, performance of some indigenous insect predators and vertebrate predators and efficacy of different liquid and granular insecticides along /with hazardous effects on the beneficial organisms such as fishes and frogs were conducted for controlling BPH in different rice season during December, 2002 to August, 2004 in Bangladesh Institute of Nuclear Agriculture (BINA). Among the six treatments of cultural practices, removal of older leaves from the rice plant in the field with no stagnant water and bending of plants provided a good control of the pest. The predatory spiders and insects significantly reduced the BPH population. The wolf spider showed the highest efficiency in controlling brown planthopper as compared to the predatory insects viz. mirid bug, lady bird beetle and carabid beetle. Release of 3-7 wolf spiders per 20-40 BPH was found to cause complete reduction of BPH in 4 to 5 days time. The mirid bug showed predator efficiency almost close to wolf spider. In evaluating the performance of three vertebrate predators viz. ducklings, frogs and fishes the better result was found with the treatment of ducklings. The performance of the vertebrate predators were in the order as ducklings > frogs > fishes. Among all the biological control agents it was evident that the ducklings were capable to reduce BPH population in a short period of time. In determining the effectiveness of insecticides against this pest Basudin 10G was found to be the most effective insecticides followed by Baycarb 500EC, Cidan 4G, Biesteren 5G, Nimbicidine and Diazinon 60EC. All the chemical insecticides were found to leave hazardous effect onto fishes and frogs. Nimbicidine, a botanical based insecticides was found to be less hazardous to the beneficial organisms. Fingerlings of different fishes were more susceptible to the insecticides than the frogs. The results of different experiments indicated the possible use in integrated management of brown planthopper.