Figure 1 .

The ventral appendages of Tribolium castaneum include the antennae, mouthparts (mandibles, maxillae, and labium), thoracic legs, and genitalia. (A) Ventral view of an adult female. The thoracic legs of T. castaneum are roughly similar, with six true adult podomeres: coxa, trochanter, femur, tibia, tarsus, and pretarsus. The tarsus is subdivided by joints into tarsomeres, which lack independent muscles. The prothoracic leg (B) and mesothoracic leg (C) have five tarsomeres, whereas the metathoracic leg has four tarsomeres (D). The coxae of each type of leg have distinct shapes and sizes. (B′) Larval legs consist of five main segments: the coxa, trochanter, femur, tibiotarsus, and pretarsus. Abbreviations: cx, coxa; fe, femur; pt, pretarsus; t1-5, tarsomeres 1-5; T1–T3, thoracic segments 1-3; Ti, tibia; Ts, tibial spur; tt, tibiotarsus; tr, trochanter.