TEMPERATURE COUPLING AS AN EMERGENT PROPERTY: PARALLEL THERMAL EFFECTS ON MALE SONG AND FEMALE RESPONSE DO NOT CONTRIBUTE TO SPECIES RECOGNITION IN AN ACOUSTIC MOTH

• Published in: Evolution Vol. 61; no. 7; pp. 1590 - 1599
• Main Authors: Greenfield, Michael D, Medlock, Chelsea
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Science Inc 01.07.2007; Blackwell Publishing Inc; Society for the Study of Evolution; Oxford University Press; Wiley
• Subjects: Achroia grisella; Acoustic coupling; Animal Communication; Animal reproduction; Animals; Bats; Communication; Evolution; Evolutionary biology; Female; Female animals; Genetic correlation; Genetic Variation; Inbred strains; Insects; Life Sciences; Male; Male animals; Mating behavior; Moths; Moths - genetics; Moths - physiology; Original s; Reproductive Biology; reproductive isolation; sexual selection; signal evolution; Species Specificity; Temperature; Temperature effects
• ISSN: 0014-3820; 1558-5646
• DOI: 10.1111/j.1558-5646.2007.00140.x

Temperature coupling exists when changes in male signal production with temperature are paralleled by changes in female response. Such thermal effects have been observed in various ectothermic animals producing acoustic, visual, and electric signals in which the signal rate may be subject to stabilizing selection imposed by female preference. Often, coupling was considered as an adaptive function wherein male and female thermal effects coevolved under selection pressure favoring species recognition, although this assumption has not been tested definitively. We investigated thermal effects on pulse-pair rate in male song and female acceptance threshold for male song rate in an acoustic moth, Achroia grisella, in which male song rate is subject to directional selection. Male song rate and female acceptance threshold do exhibit parallel increases as temperature rises from 18°C to 30°C, but female thresholds are much lower than male song rates and the thermal effect on female response cannot augment species recognition. In further investigations using inbred lines of A. grisella we found that the male and female thermal effects are genetically correlated, and we discuss the likely sources of this covariance. We consider several explanations for the occurrence of temperature coupling in this species and suggest that it represents an emergent property arising from the neuromuscular responses to temperature that are common to several physiological systems.