Hosmer Lake is fabulous. Fish in both ends of the lake and in the channels too. Callibaetis are just getting off to the 2025 start and the best is coming over the next 4 or 5 weeks, with a 2nd brood returning in August. 
Damsel Nymphs, Soft Hackles, Scud, Alderflies (use a Black Elk Hair Caddis in #14) and Chironomids (especially Red Ice Cream Cones #16 and Red Holo Jig). Balanced Leeches are often really effective in the lower lake and add Blobs there too. You can strip or indicator fish with either and perhaps run them as a combination rig. 
I think it is entirely possible to see flying ant there this week with the warm days coming.