Oviposition decreased in response to enriched water: A field study of the pitcher-plant mosquito, Wyeomyia smithii

1. Environmental cues are known to influence oviposition behaviour in mosquitoes, with important consequences for larval survival and insect population dynamics. Enriched microhabitats have been shown to be preferred oviposition sites. 2. In a field experiment designed to determine whether ovipositing mosquitoes are sensitive to different levels of nutrient enrichment, new pitcher-plant (Sarracenia purpurea) leaves were opened and enriched with 0, 2, or 20 dead ants, and the number of pitcher-plant mosquito (Wyeomyia smithii) larvae resulting from subsequent oviposition were measured. 3. Oviposition rates were higher in leaves with low levels of enrichment (0 and 2 ants per leaf), although larval development was enhanced at the highest enrichment level. 4. Results suggest that, although these mosquito larvae are nutrient limited, ovipositing females preferentially avoid highly enriched leaves. This counterintuitive result may be due to low oxygen concentrations or a masked cue in enriched leaves, and contrasts with other oviposition studies.