Abstract
Tracheal volume (Vtr) was measured in pupae of the Giant silkworm moth Hyalophora cecropia (Saturniidae, Lepidoptera, Insecta) using inert gas wash-out techniques. The animal was placed in a small vessel that was continuously ventilated (rate V̊) by a gas mixture containing 20% in N 2; the inflowing (FI i) and outflowing gas fractions (F e) of the vessel could be continuously measured by a respiratory mas spectrometer. At the onset of a spiracular constriction period, which was evidenced from the F e CO2 emerging from the animal, M N2, was calculated from V̊ and the difference (F E−F I) N2 . V tr was calculated from M N2 and the N 2 concentration in the tracheal system before constriction (assumed to equal that in the ventilating gas before replacement by Ar). Measurements were repeated with N 2 and Ar replacing each other. V tr averaged 48 μl·g −1 (range 39 to 59) for animals of 5.8 g average body weight (range 3.4 to 9.9), when inert gas solubility in body fluids was accounted for. Both size and stage in pupal development appear to affect V Tr. These values show reasonable agreement with literature data, mostly obtained by emptying the tracheal gas space by mechanical compression.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.