Vrinted in Great Britain PHYSIOLOGY AND ENERGETICS OF PRE-FLIGHT WARM-UP IN THE EASTERN TENT CATERPILLAR MOTH

Thoracic temperature (Tth) during pre-flight warm-up increased linearly with time at all air temperatures (Ta). The rate of pre-flight warm-up increased from 3-3 to 12-7 °C/min between Ta's of 14 and 28 °C. Head temperature remained within a few °C of Tth during warm-up, while ventral abdominal temperature remained within a few °C of Ta. Pulsation rate of the dorsal vessel in the thorax increased directly with thoracic temperature. Wing-stroke frequency (n) varied from 15 s"1 at r th = 16 °C to 58 s- 1 at 7"th = 40 °C and was similar at any given Ttb between Ta's of 14 and 28 °C. While stroke amplitude varied significantly between warm-up and tethered flight, stroke frequency was similar for the two activities in the same Tlb range. Calculated rates of heat production were tightly coupled to Tlb and did not vary with Tu. The change in heat production during warm-up was dependent entirely on changes in frequency of muscle contraction. Stroke work was constant at o-68 mW between Tlb of 15 and 40 °C