Adult feeding and oviposition preferences and larval performance of the pea leafminer, Liriomyza huidobrensis (Blanchard), were examined on pea, potato, lettuce, gai lan, celery, cucumber, and onion in the laboratory and Þeld. Host preference for feeding and oviposition varied among pea leafminer subpopulations when density measures were used but not with proportional measures. Proportion of oviposition punctures may be a more appropriate measure of oviposition preference than egg density for leafmining ßies, because it is not impacted by factors affecting stippling density. No correlations were found between preference and performance parameters in this highly polyphagous ßy.