Would you agree with this statement?

[mhorowit]

If they can do better than syrup, they will go to it.

If you agree, than open syrup away from the hive can tell you if you have a flow or not.

[bejay]

will always use syrup to an extent how much they use of it may change.

[Keefis]

I tried to feed my bees syrup earlier this year in spring and they did not seem to eat any of it. There was of course a bunch of stuff blooming at the time.
Recently, in the mid to late summer they seem to have changed their minds, and they polish off a quart in a day(each hive).
Unfortunately the only way to know how your bees are is to test when you do have a flow, to confirm.
A lot of people say it, when have people ever been wrong? hee hee

[wadehump]

flow in spring will not take much syrup dearth in summer will take as much as you put out

[NasalSponge]

I don't know about syrup but they will completely ignore honey set out if a good flow is on....this I have seen many times.