I searched on bio-numbers for flicker-fusion threshold of insect eyes in general and for flies in particular. Ruck, 1961 gives values for some flies. Is there any database maintained for these values? Is there any comparative study done for many flies/insects?
"The flicker fusion frequencies of six laboratory insects, and the response of the compound eye to mains fluorescent ‘ripple’" (Miall, 1978) touches on flicker fusion thresholds for six different insect species commonly used in laboratory settings:
Locusta migratoria, Periplaneta americana, Saturnia pavonia, Antheraea pernyi, Glossina morsitans and Drosophila hydei.
I also found this paper: Potential Biological and Ecological Effects of Flickering Artificial Light (Boyles, 2014) that includes an exhaustive literature search of flicker-fusion thresholds and other related data for many species (including insects). If you're looking for an authoritative source, I'd say that this is it (as there doesn't seem to be a database with this information).