QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by HEINRICH, B. Search for Related Content PubMed PubMed Citation Articles by HEINRICH, B.

Journal of Experimental Biology 54,153-166 (1971)
Published by Company of Biologists 1971

Temperature Regulation of the Sphinx Moth, Manduca Sexta : II. Regulation of Heat Loss by Control of Blood Circulation

BERND HEINRICH ¹

¹ Department of Zoology, University of California, Los Angeles, California 90024; Department of Entomology and Parasitology, University of California, Berkeley, California 94720

1. The circulatory anatomy of Manduca sexta is such that heat loss from the thorax is minimized when the flow of blood is reduced, and maximized when it is increased.

2. Abdominal temperatures immediately after flight suggested that blood flow was substantially increased during flight at high T_A, and greatly reduced during flight at low T_A.

3. When the thorax was artificially heated, the pulsation rates of the abdominal blood vessel increased, the amplitudes of the pulsations became large, and the pulsations were always in the posterior-anterior direction.

4. Heating of the abdomen often resulted in the constriction of the abdominal vessel and a reduction in the amplitude of the pulsations.

5. Transection of the ventral nerve cord reduced the frequency of the high-amplitude pulsations and abolished the ability of the abdominal heart to respond to thoracic heating.

6. When the heat was applied to the thorax, but not to the abdomen: (a) T_Th increased while T_Ab remained near T_A; (b) T_Ab then increased while T_Th stabilized near 40-42 °C; (c) finally, if the heat input was not excessive, T_Ab also stabilized at a temperature above T_A.

7. Neither stabilization of T_Th nor increase of T_Ab were observed during thoracic heating of dead moths or those with transected nerve chords.

8. The distribution of temperature observed in the abdomen during thoracic heating is not explicable in terms of heating by conduction from the thorax.

9. During modest thoracic heating, decreases of T_Th were correlated with intervals during which there were full-length pulsations of the dorsal vessel. During periods where movement of the vessel was observed only at the anterior end of the abdomen, the temperature of the thorax increased.

10. Calculations of blood flow and heat flux indicate that the regulation of T_Th in the observed range is physically reasonable by blood circulation alone.

This article has been cited by other articles:

				P. M. Koladich, S. S. Tobe, and J. N. McNeil Enhanced haemolymph circulation by insect ventral nerve cord: hormonal control by Pseudaletia unipuncta allatotropin and serotonin J. Exp. Biol., October 15, 2002; 205(20): 3123 - 3131. [Abstract] [Full Text] [PDF]

				A. Smits, W. Burggren, and D Oliveras Developmental changes in in vivo cardiac performance in the moth Manduca sexta J. Exp. Biol., January 1, 2000; 203(2): 369 - 378. [Abstract] [PDF]

				B. Heinrich Thermoregulation in Endothermic Insects Science, August 30, 1974; 185(4153): 747 - 756. [Abstract] [PDF]

				B. Heinrich and P. H. Raven Energetics and Pollination Ecology Science, May 12, 1972; 176(4035): 597 - 602. [PDF]