I have the yellow sticky cards, white sticky cards, and then I have blue sticky cards. Two-sided makes a little sense though. The colors are what attracts the insects, but I am quite sure that many are "captured" by accidentally flying onto the sticky surfaces. My cards do a great job but I don't have lady bugs, or at least only a few that make it into the greenhouses on their own.
I am going to hang some of the yellow sticky cards in my S room. I have a few persistent white flies and I am sure have some fungus gnats too.
Here is what part of a card looks like after 2 wks. I typically have six hanging in each greenhouse and they are all loaded with bugs after 4-6 months.
