Megachile mendica

Flat-tailed Leafcutter Bee

Leafcutter bees, genus Megachile, are solitary insects that construct nests in narrow cavities. Females find a cavity and then construct of a series of cells made of pieces of leaves and petals that they cut with their mandibles.Females have a conspicuous scopa ("pollen basket") of long hairs on their lower abdomens with which they transport pollen. Female abdomens are somewhat pointed. Males tend to be smaller, with very hairy faces and blunter abdomens (no scopa and no stinger). When a female leafcutter bee finds a suitable cavity she then finds suitable foliage and flowers to cut to construct cells. They cut round pieces for a base and then oval pieces for the walls. Cells are usually built of leaf fragments on the outside and then lined with petal fragments if suitable flowers are in the vicinity. Females then provision the open cell with a mixture of pollen and nectar. An egg is laid on the pollen mass and females then cut additional round pieces of foliage to cap the cell. Each cell is about half an inch long. This process is repeated so that the cavity is eventually filled with eight or nine cells and capped with sometimes numerous, round leaf fragments. Females are able to control the sex of their offspring by withholding sperm from male eggs. Because males develop faster than females they emerge first from the nest so the mother bee lays female eggs in the deepest cells and male eggs closer to the entrance. New leafcutter bees have to chew through the intervening cells to exit the nest, but they wait until their younger siblings have emerged before them. In other words, they do not chew up any siblings that block their exit. Leafcutter bee grubs are legless and pale. They molt as they grow and finally develop into a prepupa that spins a tough, silken cocoon that soon turns dark brown. These grubs then molt into pupae that eventually molt into new adults. The last eggs laid in late summer and early fall hatch into grubs that develop into a prepupal stage that overwinters inside the cocoon. Warming temperatures the next spring induce the prepupae to molt into pupae from which new adults emerge later.
REF:https://content.ces.ncsu.edu/leafcutter-bees#section_heading_11038