Philippine E-Journals

Aboveground Arthropod Composition, Abundance and Guild Structure in Upland Rice Agro-ecosystem at Matalam, North Cotabato, Philippines

Gina D. Balleras | Leah E. Endonela

 

Abstract:

With the recent innovations in the field of ecological pest management, conservation and enhancement of biological diversity at any rice agro-ecosystems has received considerable attention. The composition and abundance of above ground arthropods was assessed on upland rice fields in Matalam, North Cotabato, Southern Mindanao, Philippines. Sampling and monitoring was done using malaise trapping, sweep netting and direct counting techniques. A total of 29 arthropod species belonging to 21 families in nine orders were documented. The collected samples were comprised of 40% insect pests, 53% predators and 7% parasitoids. The three most abundant insect pests were rice bug (Leptocorisa oratorius), rice seedling maggot (Atherigona oryzae), and pink stemborer (Sesamia inferens). _e predators are dominated by lady bird beetle (Micraspis spp.), social wasp (unknown) and long-jawed spider (Tetragnatha maxillosa). Ichneumonids, Braconids and Tachinids, though in smaller numbers, were present throughout the cropping season. More importantly, the study reported the presence of four rice stem borer species – Scirpophaga innotta, Scirpophaga incertulas, Sesamia inferens and Chilo suppressalis and two rice grain bug species – Paraeucosmetus pallicornis and Elasmolomus sordidus in Matalam. The occurrence, composition and abundance of insect pests and associated natural enemies vary with rice growth and developmental stages. The negative Pearson’s correlation coe_cient (r = -0.31) between the insect pests and natural enemies was attributed to effective cultural management practices which have been developed through decades of subsistence upland rice farming.