Occurrence of major insect pests and their natural enemies of rice at San Mateo, Isabela [Philippines]

Insect pests and natural enemies were assessed using a light-trap installed in the field at PhilRice, San Mateo [Philippines] during 2002 dry and wet season in order to determine the abundance and peak of time of colonization of insect pests and natural enemies as a guide in determining an appropriate and friendly strategies to manage them. In San Mateo, Isabela, brown planthopper (BPH) and whitebacked planthopper (WBPH) were the most dominant insect pests, while the most dominant natural enemy were carabid beetles and plant bug during the dry and wet season. Insect pest population was observed at increasing trend from January to February and finally peaked during the first week of March dominated by WBPH and BPH with a total of 16,684 and 15,093 individuals (nymphs and adults), respectively. Population of insect pests was observed at increasing trend from July to August and finally peaked during the third and fourth week of September dominated by BPH with 95,222 and 134,412 individuals (nymphs and adults). For the natural enemies, the most dominant was carabid beetle and peaked during the second and third week of March (dry season). During the wet season, plant bug was observed the most dominant and peaked during the second and third week of October