Terrestrials can be very important...did it seem like the fish were keying in on them...? Often when they key in on some kind of terrestrial that's getting blown down onto the lake, they won't touch anything else...
Had that very experience early this year on a lake near merritt with an ant hatch...they wouldn't take anything but. Unfortunately I didn't have any ant patterns that fit the bill...now I have several...lesson learned on my part...
That one looks like some kind of longhorn beatle BCkid...