One other possible culprit could be ants. My plants get covered with milweed aphids, and they secrete a nectar which ants and wasps find wonderful. The ants will actually move the aphids around and farm them, stroking them which gets them to produce more nectar. I've seen an ant taking on two big tussock moth caterpillars a hundered times his size, with his pincers out, trying to get to their soft underbody. I'm sure the ants get our eggs and first and second instars too, while roaming around the plants.
Precious little miracles with wings, and an awesome God!