Recent research on Hover flies (Diptera: Syrphidae) in the Netherlands shows this group is suffering from a higher extinction rate than thought in the last decades. Between 1993 and 2017 it is five times higher than the period of 1942-1992, and even two times higher than the current extinction rate for solitary bees. The percentage for bees is stable while it is accelerating for hoverflies.
The authors arrive at these conclusions based on studying a combination of data sources. Pollution, toxicity of pesticides and climate change are identified as possible causes.

So again, more alarming news considering our pollinators and insects in general.

Journal of Syrphidae source article