The first abdominal segment when fused with metathorax in bees is known as

The first abdominal segment when fused with the metathorax in bees is known as Propodeum.
Propodeum is part of the thorax of a hymenopteran that lies immediately over and partly surrounding the insertion of the petiole of the abdomen and represents a basal abdominal segment that has become fused with the thorax.
The first abdominal segment is called propodeum. It is fused with metathorax. The first pair of abdominal spiracles are located in the propodeum. The second segment is known as pedicel which connects the thorax and abdomen.