Patterns of Thermal Sensitivity and Sex-Specificity of Courtship Behavior Differs Between Two Sympatric Species of Enchenopa Treehopper

Abstract

Predicting how insects will react to future thermal conditions requires understanding how temperature currently affects insect behavior, from performance traits to those involved in mating and reproduction. Many reproductive behaviors are thermally-sensitive, but little is known how temperature affects the behaviors used to find mates and coordinate mating. Here, we investigate how temperature influences courtship activity in two sympatric species of Enchenopa treehoppers (Hemiptera: Membracidae). Enchenopa use substrate-borne vibrational signals exchanged in male-female duets to facilitate pair formation prior to mating. In a controlled laboratory setting, we assessed the likelihood of males and females to produce courtship signals across a range of ecologically relevant temperatures. We found that changes in courtship activity across temperatures differed between the two species. We also found sex differences within species: in one species males were more likely to signal at higher temperatures, while in the other species females were more likely to signal at higher temperatures. Our results suggest that sex-specific responses to temperature may constrain mating to narrower ranges of temperatures. Furthermore, sympatric species may respond differently to changes in thermal variation despite sharing similar climactic history.

Harvesters (Arachnida: Opiliones) mate more at cooler temperatures, but the effect of temperature on mating varies across years

“…Behavioral processes at all stages of mating change with temperature as a result (Leith et al, 2021). In the precopulatory stages, temperature affects the likelihood of individuals engaging in a precopulatory activity—an important prerequisite for mating in many animals—with the highest activity often occurring at intermediate temperatures (Brandt et al, 2018; Eberhard et al, 2019; Leith et al, 2020; Macchiano et al, 2019). Thus, the likelihood of mating to occur also often peaks at intermediate temperatures (Huey & Stevenson, 1979; Leith et al, 2020; Leith et al, 2021) with notable exceptions (Brandt et al, 2018).…”

Warm developmental temperatures induce non‐adaptive plasticity in the intrasexually selected colouration of a dragonfly

“…Overall, thermal plasticity in wing colouration appears to be non‐adaptive relative to the known production costs, as well as intrasexual selection, with respect to wing colouration in this population of P. longipennis (Moore & Martin, ; Moore et al ., ; Moore et al ., ). Thus, unlike some sexually selected signals in other insects (Beckers & Schul, ; Jocson et al ., ; Macchiano et al ., ), temperature‐mediated variation in intrasexual selection has not generated adaptive thermal plasticity for wing colouration. Without adaptation, this response in wing colouration may become particularly detrimental as the climate continues to warm: sexual and ecological sources of selection will favour less and less wing colour, whereas the developmental temperatures induce the expression of more and more.…”

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

“…Many studies that describe behavioral responses to temperature focus on performance traits like sprint speed and locomotion (Bennett, 1980, 1990; Cullum, 1998; Green & Fisher, 2004; Hertz, Huey, & Nevo, 1983; Lailvaux, Alexander, & Whiting, 2003); in contrast, the thermal sensitivity of mating‐related traits has received less attention (Andrew et al., 2013; but see Brandt, Kelley, & Elias, 2018; Rosenthal & Elias, 2019; Macchiano, Sasson, Leith, & Fowler‐Finn, 2019). Because reproductive behaviors are closely tied to Darwinian fitness, understanding how temperature affects mating‐related behaviors is central to understanding the fitness effects of thermal variation (Sinclair et al., 2012; Visser, 2008).…”

“…Many ectotherms mate within specific thermal windows because physiological constraints can limit mating‐related behavior to intermediate temperatures (Huey & Stevenson, 1979). For example, in sexually reproducing species, temperature‐related constraints on activity levels, mate localization, and copulatory behaviors could all influence the coordination of mating (Brandt et al., 2018; Candolin, 2019; Flanagan & Bevier, 2014; Macchiano et al 2019) with potentially important consequences for reproduction in a thermally variable environment.…”

“…When the thermal sensitivity of courtship activity in males and females are similar, patterns of mating across temperatures are likely to align with the activity levels of both sexes. However, sex‐specific thermal responses ( e.g., Kvarnemo, 1994; Cullum, 1998; Lailvaux et al., 2003; Darnell, Fowler, & Munguia, 2013; Condon et al., 2015; Brandt et al., 2018; Macchiano et al., 2019) stemming from differences in behavior and physiology—for example, differences in body size, metabolic costs, and extra heat produced by mating‐related activity (Beaupre & Duvall, 1998; Block, 1994; Brown & Weatherhead, 2000; Cullum, 1998; Kingsolver & Huey, 2008)—may generate mismatches in the timing of when males and females are most actively seeking or receptive to potential mates. When mismatches between male and female responses to temperature occur, the activity patterns of one sex could disproportionately constrain mating rates or the activity patterns of both sexes may interact to determine patterns of mating across temperatures.…”