Climate change is altering precipitation patterns globally, leading to more frequent and severe drying periods that disrupt stream flow regimes and degrade water quality. Drying streams experience increased temperatures, lower oxygen concentrations, and sediment accumulation; however, the effects of these changes on aquatic insect emergence remain uncertain. Since insect emergence is crucial for aquatic food webs and energy transfer to terrestrial ecosystems, understanding its response to flow reduction is essential. To investigate these effects, we measured insect emergence in two tropical streams in Puerto Rico. We experimentally manipulated flow in one stream across three dry seasons (March–July 2022, 2023, 2024) to extend the dry period, aligning with global change projections for our study site. Flow was reduced by ~40%. A nearby stream served as a control. Insect emergence was quantified using four 1 m² emergence traps per site, traps were place in the stream for four days and insect emergence was expressed as individuals per day. We found that Diptera consistently increased under flow reduction (0.85-fold on average, with the highest increase in 2023 at 1.67-fold), likely benefiting from sediment accumulation, particularly the family Chironomidae. Ephemeroptera responses varied between streams, suggesting that substrate conditions and algal growth influence their emergence. Trichoptera showed no clear response to flow reduction. Interestingly, similar patterns were observed in the control stream, indicating that broader environmental factors may also drive emergence trends. These findings highlight the complexity of aquatic insect responses to drying and underscore the need to account for both experimental and natural variability when predicting the ecological consequences of altered flow regimes in tropical streams.