Populations Abundance of Major Insect Pests and Their Predators in floatiing Rice Fields

Abstract

Numbers of population of major insect pests an dtheir predators in floating ric efarmer fields were monitored in the province of Sa Kaew. Prachin Buri, Nakhon Nayok an Phra Nakhon si Ayutthaya since 1994 - 1996. Populations of insect p ests and predators were collected across fields by a sweeping net. The pattern of major insect pests popluations in floating rice fields could be conuluded that population number of white-backed planthopper (Sogatella furcifera) were high at the early growth stage of floating rice from june-july. Population mumbers of green leafhopper (Nephotettix virescens) were high almost throughout the growint season of floating rice from June-October. However, brown planthopper (Nilaparvaa lugens) and zigzag-leafhopper (Recilia dorsalis) populations were low throughout the grwoing season. Population of yellow stem borer (Scirpophaga incertulas) and striped stem borer (Chilo supperssalis) were high at some areas from August-November. Popluations of long-jawed spider (Tetragnatha maxillosa) , damselfly (Agriocnemis femina femina) and lady beetle (Micraspis discolor, Coccinella transversalis) were the mos thighest in all monitoring areas throughout the growing seasons.