Details of Award
NERC Reference : NE/T007885/1
Understanding heatwave damage through reproduction in insect systems
Grant Award
- Principal Investigator:
- Professor A Maklakov, University of East Anglia, Biological Sciences
- Co-Investigator:
- Dr LG Spurgin, University of East Anglia, Biological Sciences
- Co-Investigator:
- Dr A Franco, University of East Anglia, Environmental Sciences
- Grant held at:
- University of East Anglia, Biological Sciences
- Science Area:
- Terrestrial
- Overall Classification:
- Panel C
- ENRIs:
- Biodiversity
- Environmental Risks and Hazards
- Global Change
- Science Topics:
- Animal reproduction
- Conservation Ecology
- Population Ecology
- Abstract:
- Recent long-term field surveys have revealed 'catastrophic' declines in insects, even in areas protected from habitat loss and pesticides. Climate change is the likely cause, but we still have 'disturbingly limited knowledge' about proximate drivers of biodiversity loss under global warming (Cahill et al 2013). This project will examine one key driver, by testing the hypothesis that exceptional thermal sensitivities within reproduction can explain why insect populations are declining. Under climate change, extreme conditions such as heatwaves are getting more frequent and severe, and such thermal variation may damage biodiversity more than average change. Male reproductive sensitivity to heat is well known in endotherms, but ectotherms have received scant attention, despite comprising most of biodiversity, and being directly affected by the thermal environment. In a recent NERC project, we identified in our Tribolium beetle model that reproduction is exceptionally sensitive to warming: heatwaves at 5-7oC above the population optimum for 5 days damage male fertility and sperm function, and a second heatwave almost completely sterilises males (Sales et al. 2018: Experimental heatwaves compromise sperm function and cause transgenerational damage in a model insect. Nature Comms). Female reproduction, by contrast, is resilient to heat, but is compromised via thermal damage to sperm in female storage. In addition to these direct impacts, we also revealed less obvious transgenerational damage to reproductive fitness and lifespan of offspring if fathers or fertilising sperm (in female storage) had experienced heatwaves. Because a) reproduction is essential for population viability, b) heatwaves are becoming more frequent and severe, and c) most species on Earth are insects in worrying decline, we propose to measure how experimental heatwaves impact on: 1) reproduction across a suite of tropical and temperate insect species; 2) thermal vulnerabilities at different life stages and whether any damage is permanent; and 3) heatwave impacts on population resilience, viability and extinction. As proposed by recent expert reviews, we will tackle these important questions using systematic experiments across three complementary work packages: 1) MEASURE REPRODUCTIVE SENSITIVITIES IN DIFFERENT INSECT SPECIES. Building on our results from Tribolium beetles, we will investigate how heatwaves impact on sex-specific and gamete-specific reproduction across nine temperate and tropical insect model systems. We have chosen species that represent some major Orders and ecologies, and which we know from experience will breed readily within controlled lab experiments. Heatwave conditions will be simulated where temperatures exceed the average local temperature during breeding for the population by >5oC for 5 days. 2) MEASURE DIFFERENT LIFE STAGE SENSITIVITIES TO HEATWAVE CONDITIONS. Experimental work with Tribolium beetles revealed that heatwave conditions (5-7oC above the optimum for 5 days) halved the reproductive output of mature males and their sperm. New pilot data now reveal that immature males become completely sterile under the same conditions, and pupae suffer high mortality. We will therefore measure the relative vulnerabilities of embryonic, larval, pupal and adult life stages to heatwaves in beetle and moth models, and assess impacts on survival, development, reproduction and transgenerational effects in both sexes, and whether the damage is permanent. 3) MEASURE HEATWAVE IMPACTS ON INSECT POPULATION VIABILITY. Using Tribolium beetle and Plodia moth models which have proven value for the tracking of longer-term, whole-population impacts, and incorporating information about stage sensitivities from 2) as the project progresses, we will measure and model how heatwaves cause longer-term declines and extinctions in replicated populations, gaining broader insight into how extreme weather across life stages influences insect biodiversity.
- NERC Reference:
- NE/T007885/1
- Grant Stage:
- Awaiting Event/Action
- Scheme:
- Standard Grant FEC
- Grant Status:
- Active
- Programme:
- Standard Grant
This grant award has a total value of £541,323
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | DA - Investigators | DA - Estate Costs | DI - Staff | DA - Other Directly Allocated | DI - T&S |
|---|---|---|---|---|---|---|
| £100,682 | £145,891 | £41,212 | £36,330 | £206,369 | £2,706 | £8,130 |
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