The effects of carbofuran, isofenphos and neem on the principal pests of rice and parasites of the rice cecidomyiid, in Burkina Faso.
In the rainy season in Burkina Faso in 1988, extracts of crushed neem seeds applied to rice every 7 and 14 days up to the 63rd day after sowing gave similar results to the insecticides carbofuran and isofenphos against a range of insect pests that included Orseolia oryzivora, Maliarpha separatella, Epilachna similis and Chilo sp. However, under the combined action of heavy pest pressure and washing neem subsequently proved ineffective. Although the synthetic insecticides could increase yields by 2- or 3-fold, they reduced natural parasitism of O. oryzivora by Platygaster sp. and Tetrastichus by 15-30%.