Sounds like something a LLM could answer for you:

The extinction of mosquitoes could lead to several ecological problems, primarily affecting food chains and ecosystems that rely on them. While some species may adapt, others could face significant challenges. For instance, specialized predators like the mosquitofish might struggle without their primary food source, potentially leading to population declines.

In the Arctic, mosquito populations serve as a crucial food source for migratory birds, and their absence could result in a decline in bird populations by more than 50%.

Additionally, mosquito larvae are an important food source for various fish species, and their extinction could disrupt aquatic food chains.

Although some animals might adapt by finding alternative prey, the overall impact on biodiversity and ecosystem stability remains a concern.

The loss of mosquitoes could also affect pollination, although most plants do not solely rely on them for this process.

My concern with this is that the "solutions" usually involve using some gene editing tech like CRISPR on them. This creates: flying, heat seeking and gene edited hyperdermic needles that breed like crazy.