Here's a picture of the development of a leaf-cutter bee species we collected in our bamboo nests. After eating all of the provisioned pollen within its cell, the last instar larva (left) molts into a new pupa (2nd from left). The older pupa (2nd from right) looks much like an adult bee (right) but is still developing it's wings and other internal anatomy.
I am a researcher at CU-Boulder leading a USDA funded project looking at native bee diversity in agricultural landscapes of eastern Colorado. Please enjoy your visit and contact me if you have any questions.