Mosquito larvae often subsist on inputs of terrestrial-derived resources, including leaves and dead insects. However, seasonal inputs of plant pollen is an underexplored resource for many species. We compared the effects of three levels (low, medium, high) of two pollen types (corn, pine) on development, mass, and survival in Anopheles quadrimaculatus (Say) and Culex quinquefasciatus (Say) (Diptera: Culcidae). We also examined the nutrient content of adults (%nitrogen, %carbon, C:N) and stable isotopes (δ¹⁵N, δ¹³C). Culex quinquefasciatus had the highest survival rates when grown on high and medium pine pollen compared with low pine. Survival of Culex quinquefasciatus was generally higher compared to that of An. quadrimaculatus on any level of pine, with the latter species having higher survival in high corn. Nutrient content for An. quadrimaculatus did not vary significantly in either pollen type or amount but were more enriched in δ¹⁵N in corn pollen relative to pine pollen. For Cx. quinquefasciatus, %N decreased and C:N ratio increased across low to high amounts of corn. Adults raised in corn had generally more δ¹³C compared to pine pollen. No developmental differences across diets were observed for either species, however both sexes of Cx. quinquefasciatus were generally larger when grown in high pine and medium and high corn pollen compared with other treatments. The poor performance of An. quadrimaculatus on corn pollen was unexpected, however, we show a benefit of corn pollen to Cx. quinquefasciatus with implications for West Nile virus transmission in the United States, especially around agricultural areas where corn is grown.