Temperature‐related breakdowns in the coordination of mating in Enchenopa binotata treehoppers (Hemiptera: Membracidae)

• Published in: Ethology 2020-09, Vol.126 (9), p.870-882
• Main Authors: Leith, Noah T., Jocson, Dowen I., Fowler‐Finn, Kasey D., Goymann, Wolfgang
• Format: Article
• Language: English
• Subjects: Animal reproduction; Coordination; Copulation; Courtship; Females; Hemiptera; Insects; Mating; Mating behavior; Membracidae; Pair bond; plasticity; Playbacks; Sensitivity; Sex; Sexual behavior; sex‐specific responses; Temperature; Thermal environments; thermal sensitivity; vibrational communication; Vibratory communication
• ISSN: 0179-1613; 1439-0310
• DOI: 10.1111/eth.13033

Temperature influences the expression of a wide range of behavioral traits in ectotherms, including many involved in the initiation of pair formation and mating. Although opportunities to mate are thought to be greatest when male and female activity overlap, sex‐specific behaviors and physiology could result in mismatched thermal optima for male and female courtship. Here, we investigate how conflicts in the thermal sensitivity of male and female courtship activity affect patterns of mating across temperatures in Enchenopa binotata treehoppers (Hemiptera: Membracidae). These plant‐feeding insects coordinate mating with plant‐borne vibrational signals exchanged in male–female duets prior to pair formation. We manipulated temperature across an ecologically relevant range (18–36ºC) and tested the likelihood of individual male and female E. binotata to engage in courtship activity using vibrational playbacks. We then staged male–female mating interactions across the same temperature range and quantified the thermal sensitivity of mating‐related behaviors across stages of mating. Specifically, we measured the timing of duetting, the likelihood for key pre‐copulatory behaviors to occur, whether the pair mated, and copulation duration. We found sex‐specific thermal sensitivity in courtship activity: Males showed a clear peak of activity at intermediate temperatures (27–30ºC), while females showed highest activity at the hotter thermal extreme. Mating rates, courtship duets, and copulatory attempts were less likely to occur at thermal extremes. Also, duetting occurred earlier and copulation was shortest at higher temperatures. Overall, our data suggest that sexes differ in how temperature affects mating‐related activity and some processes involved in mate coordination may be more sensitive than others across variable thermal environments. Although male Enchenopa binotata treehoppers are most likely to court at cooler temperatures, females are more likely to respond to male courtship signals at warmer temperatures. However, how these sex‐specific effects of temperature on courtship activity translate into mating rates differs between years. Overall, many behaviors involved in reproduction are sensitive to temperature, with potentially important consequences for the coordination of mating in variable thermal environments.