Given the chemical properties of synthetic pyrethroids, it is probable that compounds including esfenvalerate that enter surface waters may become incorporated into aquatic insect food sources. We examined the effect of dietary esfenvalerate uptake in aquatic insects representing different functional feeding groups.  We utilized three field-collected aquatic insect species: a grazing scraper Cinygmula reticulata (Ephemeroptera: Heptageniidae), an omnivorous filter feeder Brachycentrus americanus (Trichoptera: Brachycentridae), and a predator Hesperoperla pacifica (Plecoptera: Perlidae). Laboratory-cultured algae were pre-exposed for 24h to esfenvalerate concentrations of 0, 0.025, 0.05, and 0.1 µg/L and provided to two C. reticulata age classes, small and final-instar nymphs. Reduction in small nymph growth was observed following three weeks feeding on algae exposed to 0.05 and 0.1 µg/L esfenvalerate, and the highest dietary exposure reduced egg production in final-instar nymphs. The diet for B. americanus and H. pacifica insects consisted of dead third-instar Chironomus tentans larvae pre-exposed for 24h to esfenvalerate concentrations ranging between 0.1 and 1.0 µg/L. Consumption of larvae exposed to 0.5 to 1.0 µg/L esfenvalerate caused case-abandonment and mortality in B. americanus caddisfly larvae. Although H. pacifica nymphs readily consumed esfenvalerate-exposed larvae, no adverse effects were observed during the course of this study. Further, there was no evidence of esfenvalerate-induced feeding deterrence in any of the species tested, suggesting that aquatic insects may not be able to distinguish between pyrethroid-contaminated and uncontaminated food sources. These findings indicate that feeding deterrence is not a factor regulating aquatic insect dietary exposures to synthetic pyrethoids.