50 r A
Beetles alive
0. rugatipennis
abdomen e-v_
thorax
50
B
A 0. brincki thorax
Δ 0. brincki abdomen
Γ
· 0. rugatipennis thorax
O 0. rugatipennis abdomen
Beetles idead
A 0. brincki thorax
Δ 0. brincki abdomen
# 0. rugatipennis thorax
O 0. rugatipennis abdomen
4:38
4 : 4 0
Local time
4:42
4:50
Fig. 20. Body temperatures of Onymacris brincki (with white elytra) and O.
rugatipennis (entirely black). (A) When living insects were transferred from shade
to sunshine the abdomen of O. brincki was cooler than its thorax, while the
abdomen and thorax of O. rugatipennis were at about the same temperature.
(B) A similar effect was obtained when dead insects were used, showing that
temperature differences were not due to differences in muscular activity. (C) When
the white elytra of brincki were covered with carbon black, the abdominal temperature rose to equal that of the black abdomen of O. rugatipennis. From Edney
(1971b).