Thermal biology of Pacific cicada killers, Sphecius convallis Patton, in the upper Sonoran desert

A comprehensive investigation of the Pacific cicada killer, Sphecius convallis Patton, was undertaken to examine the behavioral and physiological mechanisms by which they are able to complete their life cycle in the thermal extremes of the Upper Sonoran Desert. S. convallis were endothermic, exhibiting elevated and relatively constant thorax temperatures during many activities. Males basked in trees at dawn to warm up, then used a variety of behaviors and perching strategies to maintain thorax temperature during territorial behavior. The thorax temperature of females was highest during provisioning and orientation flights, somewhat lower while investigating burrows, and lowest while digging burrows. The optimal thorax temperature for flight was about 40 °C, which was approximated most closely by males resting in the shade during the afternoon. In mating clusters, the mated male was the hottest, the female was coolest and the other males were intermediate. Wasps lost about 5% of body mass during heating treatments, and may use evaporative water loss for cooling. Pacific cicada killers use a complex suite of behavioral and physiological adaptations to regulate body temperature during their nesting season.

Title	Thermal biology of Pacific cicada killers, Sphecius convallis Patton, in the upper Sonoran desert
Creator	Hastings, J. M.
	Coelho, J. R.
	Holliday, Charles W.
	Phillips, C. M.
Publisher	Journal of Thermal Biology
Academic Department	Biology
Division	Humanities
Organization	Lafayette College
Date Issued	April 2016
Date Available	2023-06-05
Type	Article
Language	English
Bibliographic Citation	Coelho, J. R. (2016 Apr) "Thermal biology of Pacific cicada killers, Sphecius convallis Patton, in the upper Sonoran desert." Journal of Thermal Biology 57: 101-109.
Standard Identifier	Handle 10385/n009w365t
Standard Identifier	DOI 10.1016/j.jtherbio.2016.03.001
Permalink	http://hdl.handle.net/10385/n009w365t
Rights Statement	In Copyright
Rights Holders	Elsevier Ltd.