Not really.
I started fishing BWO's this year first week of February.
And they can go for a good 2 months or more.
Hendricksons - my favorite - started last week of march on a central pa limestoner, (which I contacted you about)
After a week pause for high water first week of April, I continued fishing them again on Kettle creek for two weeks.
Then fished them on the Clarion river for another 2 weeks after that, when it got wadable.
And finally on to the Delaware river earlier this month, where they were still going strong as of a week ago.
Spent a month and a half just fishing them alone.
Sulphers starting now, and can be fished right through June and into July.
Often with Iso's too
And even once the spring hatches finally wind down, I catch fish on terrestrials all summer and fall.
It pays to move around