Aquatic Insect Ecology

Question 1

RCC

Answer 1

River continunem concept

Question 2

Headwater streams

Answer 2

• make up 85% of all running water kilometerage
• steep gradient, coarse substrates
• Riparian vegetation: is n.b. b/c ratio of shoreline to area of stream bottom is high
• vegetation provides:
• 1) Shade ® reduces autotrophic production (less algae)
• 2) Organic matter ® is mostly allochthonous food source
• grassland streams: trees and shrubs line waterway
• high altitude streams: steep slopes provide additional shading

Question 3

Adaptations to fast flow (6)

Answer 3

1- Flat shape to reduce resistance

2- Hooks and suckers to hold onto substrate

3- Weight

4- Good swimmersGood swimmers

5- Burrow into bottom

6- Construct retreat

Question 4

Adaptations to silt

Answer 4

1. Gill covers some mayflies
2. Rectal gills dragonflies
3. Hairy bodies dragonflies
4. Burrow many mayflies
5. Climb plants damselflies, water scorpions
6. Active swimmer beetles, water boatman
7. Breathe at surface beetles, water
   scorpions, some diptera
8. Respiratory pigments

Question 5

Sources of Disturbances

Answer 5

1. Spates
2. Drought
3. Pollution

Question 6

Describe which productivity has the most diversity

Question 7

Sources of recolonization?

Answer 7

1. Drift from upstream
2. Crawling or swimming from surrounding areas (e.g., refugia)
3. • Hyporheic(deep) zone (upwards movement)
4. -Hatching eggs, emergence of adults from pulpae
5. Flight (adult beetles and true bugs)
6. Upstream flight of emerged adults, to oviposit (Mueller’s recolonization theory, or “why don’t we run out of bugs?“)