TABLE 1.

Methane production by the three instars of P. ephippiata larvae and by isolated midguts and hindguts (third instar) incubated separately in Ringer's solution under air

Larva or gut section	CH4 production rate (μmol g−1 h−1)a	n
Larvae
First instar	0.13 ± 0.04	4
Second instar	0.12 ± 0.03	4
Third instar	0.36 ± 0.11	6
Isolated gut sections
Midgut	NDb	14
Hindgut	0.030 ± 0.007	14

^aAll values are based on the fresh weight of the whole animal and are means ± standard errors for n different larvae.

^bND, not detectable (<0.1 nmol g⁻¹ h⁻¹).