The impact of heatwaves on surveillance programmes for high-risk pests in New Zealand
This research investigates the effects of varying heat and heatwave scenarios, our project aims to understand how these increasingly common climate events could alter the chemical composition (including longevity and stability) and thus, the effectiveness of commercial pheromone-based lures.
Furthermore, we will investigate the effects of heat and heatwaves on the corresponding olfactory perception of pheromone lures (via electrophysiological and behavioral responses) by males of selected high-risk pests or their surrogates, spanning at least two generations after heat exposure.
The research approach that will contribute to planned science and biosecurity outcomes will include:
Objective 1: Years 1-3
- Rear different life stages (eggs, larvae/nymphs) from selected model insect pests and expose them independently for two consecutive generations to four controlled heat/heatwave scenarios encompassing both hot and extreme temperatures (e.g. 36°C or 40°C) over varying durations (depending on the species/life stage and their temperature threshold tolerances – if known), compared to control groups reared continuously at 25°C.
- Test the olfactory responses of F1 and F2 male pests or their surrogates, reared under the various heatwave scenarios, to their respective commercial pheromones, using Y-tube olfactometers or wind tunnels, and EAG/GC-EAD set-ups based on the species.
- This objective involves collaboration with international partners, to study specific pests: MARA-CABI in China for Halyomorpha halys brown marmorated stink bug (BMSB), Macquarie University in Australia for Bactrocera tryoni Queensland fruit fly (QFF) and Spodoptera frugiperda fall army worm* (FAW), Natural Resources Canada (NRCAN) for Lymantria dispar (spongy moth), Gyeongsang National University (GNU)in South Korea for Bactrocera depressa and PFR Lincoln for Spodoptera litura and Nezara viridula, serving as surrogates for Spodoptera spp. and BMSB, respectively. Additionally, collaboration with the National University of Colombia provides access to maize/cotton and pasture-associated FAW strains.
* Although FAW is now present in NZ, geographic variation in the genetics of Australian FAW populations has been detected; thus, the reason for including tests with this species in Australia.
Objective 2: Years 2 and 3
- Quantify the effects of heat/heat waves on commercial pheromone longevity, dispersal, integrity, odour composition, and active space under different heatwave scenarios in the laboratory at our facilities in PFR, Lincoln.
Objective 3: Years 4-5 (see comments to SAG)
- If changes in the longevity, dispersal, integrity, or odour composition of commercial pheromones are detected under the different heatwave scenarios tested, we will explore protective measures against heat damage at the proof-of-concept level, investigating stabilizing adjuvants or innovative release devices that protect against heat damage.
Contact Project Leader Adriana Najar-Rodriguez: a[email protected]