This small mayfly was on the wall of the HQ at the fish hatchery. Roger Rohrbeck (on BugGuide) identified it as a subimago male of this genus, a member of the "Small Minnow Mayflies" (Baetidae).
This was the common emperor flying on this private tract on this weekend. The most abundant Celtis on this tract of South Texas brush is C. pallida with much less C. reticulata and C. laevigata, primarily on fencerows.
Rare human spotted. Please help identify.
Along the east side of the park lake.