Fig. 3. The CO2 emission rates from the mesothoracic spiracles and
elytral case as a function of total CO2 emission in four dung
beetle species. The regression equations, for which there is a significant
correlation, are given for each species, where: m, mesothoracic
spiracular 
CO2;
el, elytral case
CO2; and
t, total
CO2. For P.
femoralis: el=0.022+0.88t, r2=0.78,
P=0.048. For S. gariepinus:
el=–0.003+0.85t, r2=0.96, P=0. For
S. striatum: m=–0.058+1.52t,
r2=0.78, P=0.02. For C. bacchus:
m=–0.021+0.86t, r2=0.98,
P=0.002.