The rice ecosystem, especially in the tropics, is a usually richly endowed with a great diversity of generalist predators and parasitoids, which tend to be more species specific. As the rice habitat is an ephemeral habitat, most pest species that can cause significant damages and yield losses are generally immigrants. Many of these pest species are also specific rice feeders, monophagous or oligophagous (limited host range). Such specialization may be constrained by local host availability. But the more successful pest species overcome this by migrating, remaining in the rice habitat for only two or three generations, possessing high genetic diversity to overcome changes in the host plants through adaptation and evolution and reproductive capacities. The rice planthoppers are such pests. Under normal undisturbed situations, the high reproductive capacities are kept in check by the huge biodiversity in the natural enemy community. Smart and sustainable pest management strategies would thus focus on maximizing these natural enemy services. Herbivores should thus not be treated as pests unless “proven guilty” that they are indeed causing economic losses (Way and Heong 1994). Prophylactic spraying is thus not smart and not sustainable and should be completely avoided as they do more harm.
In the new book “Biodiversity and Insect Pests”, the chapter we wrote presents three planks for ecological engineering that can focus on reducing the ecological fitness of many rice pests.