Comparison of insect pest complexes in different Philippine dryland rice environments: population densities, yield loss, and management

In the Philippines most of the dryland rice pests are distinct from those of wetland culture. Partitioned-growth-stage yield loss studies revealed the highest losses in dryland rice were due to sown-seed and seedling pests (ants, field crickets, mole crickets, and termites) as well as root feeders (white grubs and root aphids) and early seedling pests (seedling maggot and flea beetle) more than the common foliar wetland pests. Losses (5–71%) were highest in the sites with the smallest rice area in which pests were concentrated and the poorest soils (which constrain yield compensation) along a continuum of dryland rice habitats. Crop management practices such as overseeding and fertility management can mitigate potential losses to a large degree. Therefore integrated crop management plays a central role in integrated pest management in dryland rice cultivation where the use of insecticides should be minimized for economic and environmental reasons.