title: Stage-specific heat effects: timing and duration of heat waves alter demographic rates of a global insect pest.
abstract: The frequency and duration of periods with high temperatures are expected to increase under global warming. Thus, even short-lived organisms are increasingly likely to experience periods of hot temperatures at some point of their life-cycle. Despite recent progress, it remains unclear how various temperature experiences during the life-cycle of organisms affect demographic traits. We simulated hot days (daily mean temperature of 30 °C) increasingly experienced under field conditions and investigated how the timing and duration of such hot days during the life cycle of Plutella xylostella affects adult traits. We show that hot days experienced during some life stages (but not all) altered adult lifespan, fecundity, and oviposition patterns. Importantly, the effects of hot days were contingent on which stage was affected, and these stage-specific effects were not always additive. Thus, adults that experience different temporal patterns of hot periods (i.e., changes in timing and duration) during their life-cycle often had different demographic rates and reproductive patterns. These results indicate that we cannot predict the effects of current and future climate on natural populations by simply focusing on changes in the mean temperature. Instead, we need to incorporate the temporal patterns of heat events relative to the life-cycle of organisms to describe population dynamics and how they will respond to future climate change.
authors.affiliation: Climate Change Biology Research Group, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, TX, 77005, USA.
authors.forename: Volker H W
authors.initials: VH
authors.lastname: Rudolf
authors.affiliation: Climate Change Biology Research Group, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China. machunsen@caas.cn.
authors.forename: Chun-Sen
authors.initials: CS
authors.lastname: Ma
mesh_terms: D000818:Animals; D057231:Climate Change; D005260:Female; D005298:Fertility; D006358:Hot Temperature; D008018:Life Cycle Stages; D009036:Moths / Q000254:growth & development* / Q000502:physiology; D010058:Oviposition; D011157:Population Dynamics; D012098:Reproduction
keywords: Adult lifespan; Carry-over effect; Hot event; Plutella xylostella; Reproduction; Temperature