I spotted these two lady beetles on the underside of a passion vine leaf. The top one is a Seven-spotted Lady Beetle, the other a Variable Lady Beetle. But what got my attention was the fact that they appeared to be interested in the yellow spots on the leaf, as were several ants.
I knew that some passion vines produce these colored bumps to make it look like butterfly eggs are already there. Butterflies don’t like to lay eggs where another butterfly has already done so, though the leaf bumps aren’t foolproof in this regard (see here).
What I didn’t know was that the bumps produce nectar, which attracts ants, as was the case here. And the ants will defend this food source against caterpillars munching on the leaves. Isn’t nature fascinating!