Environmental Entomology (1986) 15, 422-426

C.R. Vega and E.A. Heinrichs (1986)
Relationship between levels of resistance to the striped stemborer Chilo suppressalis (Walker) (Lepidoptera: Pyralidae) and rice grain yield losses
Environmental Entomology 15 (2), 422-426
Abstract: Six commercial IR rice cultivars with varying levels of resistance to the striped stemborer, Chilo suppressalis (Walker), in the vegetative stage were evaluated to determine their response when infested with different levels of C. suppressalis larvae in the vegetative and reproductive stages. Resistant cultivars had the least deadhearts and whiteheads. Grain yields at five larvae per plant in the vegetative stage were reduced 66% in susceptible, 50% in moderately resistant, and 13% in resistant cultivars. Following infestation in the reproductive stage, rain yield reduction with five larvae per plant was 47% for susceptible, 14% for moderately resistant, and 15% for resistant cultivars. In both plant growth stages, percentage unfilled grains was highest in the susceptible cultivars. Considering a 10% yield loss as an action threshold, one egg mass per m² for susceptible and two egg masses per m² for resistant varieties is suggested.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Elvis Arden Heinrichs

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host
thresholds/decision-support systems

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Chilo suppressalis	Rice (Oryza)	Philippines