Magmaster,
You what is strange, when it gets to around 100+ degrees here in the summer and no one is catching much during the hot hours of the afternoon. I can just go spot the fish sitting on top and almost always get them on a pink senko or watermelon/red 4" lizrds. I have poured some pink lizards and have yet to catch anything on them. I think this is due to the fact that the will accualy chase a lizard down and on a senko you will usally catch them out of a pure reaction say the fish sees it and it has sunk more than a foot you usally wont catch them, kinda strange. As far as the delta vs. your spots it is probably the water color it always seems to have a bunch of tiny dirt particles floating around even on the clearest days.

Tight Lines,
Taylor