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 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. Articles by CASEY, T. M. Search for Related Content PubMed Articles by HEINRICH, B. Articles by CASEY, T. M.

Journal of Experimental Biology 74,17-36 (1978)
Published by Company of Biologists 1978

Heat Transfer in Dragonflies: ‘Fliers’ and ‘Perchers’

BERND HEINRICH ¹ and TIMOTHY M. CASEY ¹

¹ Department of Entomological Sciences, University of California, Berkeley, CA 94720 and Department of Environmental Physiology, Rutgers University, New Brunswick, NJ 08903

1. Both ‘perchers’ (Libellula saturata) and ‘fliers’ (Anax junius and Aeshna multicolor) remained active in the field in sunshine at air temperatures from at least 24 °C to 36 °C.

2. The percher basked at low air temperatures and regulated exogenous heat input by postural adjustments. It markedly reduced flight activity at high air temperatures but flew nearly continuously at intermediate temperatures.

3. In direct sunlight, the abdomen of L. saturata heated faster than the thorax, but this percher exhibited little or no capacity to transfer heat between abdomen and thorax.

4. In contrast, the fliers gave no evidence of behavioural thermoregulation, but both showed impressive capacities for heat transfer from thorax to abdomen.

5. When heated exogenously on the thorax the temperature of the entire abdomen of both fliers increased uniformly, but with endogenous heat production during pre-flight warm-up there was only a slight temperature increase near the anterior portion of the abdomen.

6. Removal of abdominal air sacs or immobilizing the abdomen with wax to prevent all abdominal pumping did not significantly alter the capacity to transfer heat from thorax to abdomen.

7. Ligation of the heart anywhere along the length of the abdomen abolished heat transfer. Given sufficient exogenous heat input, fliers that can regulate their thoracic temperature by transferring the excess heat to the abdomen died in about 2 min due to overheating when the heart was occluded. Under our experimental conditions the fliers appeared to thermoregulate exclusively via a control of blood circulation.

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]

				B. HEINRICH Keeping a Cool Head: Honeybee Thermoregulation Science, September 21, 1979; 205(4412): 1269 - 1271. [Abstract] [PDF]