Merdelyn T. Caasi-Lit
Jessica B. Baroga-Barbecho
John David C. Cortez
University of the Philippines Los Baños, Laguna, Philippines
Edwin A. Benigno
New Era University, College of Agriculture, Pinugay, Baras, Rizal, Philippines
How to cite :
Caasi-Lit, M. T., Baroga-Barbecho, J. B., Cortez, J. D. C., & Benigno, E. A. (2025). Oviposition preference and behavior of the Asian corn borer, Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae), on corn and non-corn plants under semi-field and mini-screen cage conditions. Philippine Agricultural Scientist, 108(Special Issue), 22–36. https://doi.org/10.62550/SIACB07250441
Abstract
Oviposition site selection in Ostrinia furnacalis is a hierarchical, multi-stage process influenced by plant phenology and spatial context. Oviposition preferences under mini-screen cage (Sampaloc) and semi-field (BL2) conditions were evaluated to determine the effects of field size, corn developmental stage, and the presence of non-corn plants on egg deposition patterns. Females deposited significantly more egg masses on 40 DAP (pre-reproductive) corn than on early vegetative-stage plants [Sampaloc: n=437 (40 DAP), n=88 (30 DAP); BL2: n=98 (40 DAP), n=84 (30 DAP)], demonstrating a strong phenological preference, particularly in Sampaloc. The presence of non-corn plants has a negligible effect on corn borer preference. Egg mass aggregation was more pronounced under mini-screen cage conditions, suggesting that restricted dispersal enhances expression of intrinsic preference. Increasing the field size reduced the observable
differentiation in oviposition between phenological stages [Sampaloc: 109.25±11.22 (40 DAP), 22±18.97 (30 DAP); BL2: 16.33±20.54 (40 DAP), 14±14.78 (30 DAP)], indicating that spatial scale modulates preference expression through encounter dynamics and movement costs. Within plants, oviposition was concentrated in the middle canopy (leaf positions 5 to 8 from the bottom) and on the abaxial leaf surface (Abaxial: x̄ =1.307, SE=0.177, 95% CI [0.960, 1.655]; Adaxial: x̄ =1.146, SE=0.162, 95% CI [0.827, 1.464]), reflecting non-random vertical and micro-site selection. Leaf surface preference was consistent across spatial contexts, suggesting that final host acceptance is governed primarily by plant structural traits. These results demonstrate that oviposition in O. furnacalis is structured by nested spatial
and developmental filters that interact to shape egg distribution. Understanding how corn phenology and spatial configuration influence oviposition provides critical baseline information for predicting larval distribution and refining insect resistance management strategies in corn production systems.
Keywords: Asian corn borer, insect resistance management, NK603 corn, Ostrinia furnacalis, ovipositional preference, host
phenology, spatial scale.
