insect tarsal segment insect metatarsus The first of the tarsal segments of the adult leg. It is located between the tibia and the second tarsal segment and is longer than the other tarsal segments. It has 8 longitudinal rows of bristles around the circumference. first segment of the tarsus FBbt:00004648 basitarsus first tarsal segment UBERON:6004648 tarsal segment 1 1st tarsal segment