W11: Invertebrate Physiology (The Insect Apocalypse) [Dr. Blair] Flashcards
1
Q
Insect apocalypse attributes? (5)
A
- Insect abundance (~75%) has declined in the last 50 years.
- Several reasons/global threats have contributed to this as a whole.
- Important orders (butterflies, beetles & bees) are disappearing as they provide us with ecosystem services.
- The physiology of insects has been negatively impacted.
- No single over-arching cause.
2
Q
What are the primary drivers towards the insect apocalypse? (5)
A
- Habitat loss/Fragmentation.
- Pollution.
- Pesticide usage.
- Invasive species.
- Climate change.
3
Q
Habitat loss/Fragmentation attributes? (7)
A
- PAs host most insect species.
- PAs have higher levels of abundance & diversity.
- Affected most species.
- Reduced access to habitat/resources.
- Biggest physiological stressors.
- Physiological stress = nutrient stress.
- No real physiological stress.
4
Q
Urbanisation effects/attributes? (5)
A
- Affected most species.
- Urban heat islands: ~1-7 degrees celcius hotter than surrounding areas.
- Major physiological stressor.
- Physiological stress = Thermal stress.
- Physiological responses of insects = heat shock proteins & acclimation.
5
Q
Habitat alteration effects/attributes? (4)
A
- Johannesburg is largest man-made urban forest.
- Afforestation.
- Alters resources & microclimates.
- Changes the guilds of insects (i.e., changes the composition & functionality of insect communities).
6
Q
Pollution effects/attributes? (6)
A
- Pollution of air & water resources, and light pollution.
- Physiological stressor.
- Physiological stress = Toxicity.
- Physiological response of insects = resistance.
- Emerging pollutants such as microplastics contribute to toxicity.
- No physiological responses to microplastics.
7
Q
Air pollution effect/attributes? (3)
A
- Affects most terrestrial species.
- Pollutants & particulate matter cause mediocre air quality in Joburg.
- Toxicity & Respiratory stress.
8
Q
Water pollution effects/attributes? (5)
A
- Affects most aquatic species.
- Lethal to sensitive species.
- Physiological stress = Toxicity.
- Use species as bio-indicators.
- Use SASS5 to assess river health.
9
Q
Light pollution effects/attributes? (3)
A
- Affects most nocturnal species.
- Affects the navigation of nocturnal species.
- Makes nocturnal species more susceptible to predation (phototaxis).
10
Q
Egs of nocturnal species that prey upon insects due to light pollution (phototaxis)? (3)
A
- Bats.
- Spiders.
- Mantids.
11
Q
Climate change effects/attributes? (4)
A
- Elevated CO2 causes dilution effect, structural effect & metabolite effect (explain when writing).
- Cause slowed growth, prolonged development, slow digestion & reduced reproduction.
- Physiological responses of insects = compensatory feeding, increase midgut length & foregut changes.
- High temperatures affect insect distributions & ranges (winners, movers & losers).
12
Q
Invasive species effects/attributes? (3)
A
- Made possible through globalisation.
- No more geographic barriers via globalization.
- Enables the introduction of invasive species.
13
Q
Egs of invasive predators/species? (2)
A
- Polyphagous Shot Hole Borer (PSHB).
- Harmonious ladybird.
14
Q
PSHB attributes/effects? (6)
A
- Arrived in SA from southeast Asia.
- Kills trees, which then have to be cut down.
- Affects ~200 tree species.
- Physiological stressor.
- Causes competition & displacement of native species.
- Short term physiological responses by native species are insufficient in the long term.
15
Q
Harmonious ladybird attributes? (2)
A
- Native species are not adapted to it.
- Short physiological responses of native species are ineffective.
