Caterpillars

Description:

Tiny moving creatures, definitely baby caterpillars. What I am interested in is the oval woolly structure they had made holes in...I am guessing they emerged from it...but eggcase from which multiple caterpillars emerge ...I am a little foxed. It looked like the mother-ship had landed and the aliens were eating up everything beginning with the ship (as moth/butterfly caterpillars do with the individual egg cases)

Habitat:

Spotted in my garden on the under surface of a Bauhinia (white) leaf.

Notes:

Mantises lay multiple eggs in eggcases as do cockroaches...but moths and butterflies???? Can anyone help?